Research Article Estimation of Diafenthiuron Residues in...
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Research Article Estimation of Diafenthiuron Residues in Cardamom (Elettaria cardamomum (L.) Maton) Using Normal Phase HPLC: Dissipation Pattern and Safe Waiting Period in Green and Cured Cardamom Capsules Johnson Stanley, 1 Subramanian Chandrasekaran, 2 Gnanadhas Preetha, 3 Sasthakutty Kuttalam, 2 and R. Sheeba Jasmine 2 1 Vivekananda Institute of Hill Agriculture, Almora 263601, India 2 Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore 641003, India 3 Agricultural Research Station, irupathisaram, Tamil Nadu 629901, India Correspondence should be addressed to Johnson Stanley; stanley icar@rediffmail.com Received 21 November 2013; Revised 9 January 2014; Accepted 13 January 2014; Published 24 February 2014 Academic Editor: Alberto Chisvert Copyright © 2014 Johnson Stanley et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Diafenthiuron is an effective insecticide used for pest management in cardamom. Residues of diafenthiuron and its degrada- tion/dissipation pattern in cardamom were determined to work out safe waiting period. Samples were collected aſter three sprays of diafenthiuron @ 400 and 800 g a.i ha −1 and the residues extracted in acetonitrile and quantified in normal phase HPLC in UV detector. Diafenthiuron was detected in 6.61 ± 0.1 min. e limits of detection (LOD) and limits of quantification (LOQ) were determined to be 0.01 and 0.05 gmL −1 . e initial deposits were found to be 3.82 and 4.10 gg −1 aſter sprays of diafenthiuron @ 400 g a.i ha −1 in the first and second experiments, respectively. Nearly cent percent of residues dissipated at 10 days aſter treatment in the recommended dose of diafenthiuron 400 g a.i ha −1 and the half life varied from 2.0 to 2.8 days with a waiting period of 5.5 to 6.7 days in green capsules of cardamom. e waiting period was 5.4 to 7.0 days in cured capsules of cardamom. With harvest being the focal point for enforcement of residue tolerances, the suggested waiting period of seven days is safe without the problem of pesticide residues in harvestable produce. 1. Introduction e pesticide use pattern in the present day situations has led to pesticide residues in the harvestable produce, resistance build-up by pests, and eradication of nontargets which demands newer and safer pesticides with differ- ent modes of action. Diafenthiuron (1-tert-butyl-3-(2,6-di- isopropyl thiourea)) is one such new insecticide, which is the only nonorganofluorine benzyl urea compound hav- ing novel insecticide/acaricide activity acting selectively on group of insects and mites [1] by inhibiting or enhancing biochemical sites such as respiration [2]. Diafenthiuron is reported to be effective against whiteflies and leaf hoppers in brinjal [3, 4], whiteflies, aphids and thrips in tomato [5– 7], thrips and mitesin chilies and tea [8, 9], and all sucking pests in cotton [10, 11]. Diafenthiuron is effective against diamondback moth (DBM) [12, 13], shoot and capsule borer, and thrips in cardamom [14] and it is gaining momentum now in cardamom plantations. Cardamom is an important spice crop grown all over the world and one of the important products fetching enormous foreign exchange. With the strict legislations enforced by the EPA, cardamom capsules with pesticide residues have a chance of being rejected by the hitherto importing countries, which in turn would have a major say in foreign revenues. Since diafenthiuron is effective against the pests of cardamom, knowledge on the residue in the economic produce, dissipation pattern, and waiting period are necessary for its proper use. Diafenthiuron is a biologically inactive proinsecticide which needs transformation into active carbodiimide Hindawi Publishing Corporation Chromatography Research International Volume 2014, Article ID 289747, 8 pages http://dx.doi.org/10.1155/2014/289747
Transcript of Research Article Estimation of Diafenthiuron Residues in...
Research ArticleEstimation of Diafenthiuron Residues in Cardamom(Elettaria cardamomum (L) Maton) Using Normal PhaseHPLC Dissipation Pattern and Safe Waiting Period in Greenand Cured Cardamom Capsules
Johnson Stanley1 Subramanian Chandrasekaran2 Gnanadhas Preetha3
Sasthakutty Kuttalam2 and R Sheeba Jasmine2
1 Vivekananda Institute of Hill Agriculture Almora 263601 India2Department of Agricultural Entomology Tamil Nadu Agricultural University Coimbatore 641003 India3 Agricultural Research Station Thirupathisaram Tamil Nadu 629901 India
Correspondence should be addressed to Johnson Stanley stanley icarrediffmailcom
Received 21 November 2013 Revised 9 January 2014 Accepted 13 January 2014 Published 24 February 2014
Academic Editor Alberto Chisvert
Copyright copy 2014 Johnson Stanley et alThis is an open access article distributed under theCreative CommonsAttribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited
Diafenthiuron is an effective insecticide used for pest management in cardamom Residues of diafenthiuron and its degrada-tiondissipation pattern in cardamom were determined to work out safe waiting period Samples were collected after three spraysof diafenthiuron 400 and 800 g ai haminus1 and the residues extracted in acetonitrile and quantified in normal phase HPLC in UVdetector Diafenthiuron was detected in 661 plusmn 01min The limits of detection (LOD) and limits of quantification (LOQ) weredetermined to be 001 and 005120583gmLminus1 The initial deposits were found to be 382 and 410120583g gminus1 after sprays of diafenthiuron 400 g ai haminus1 in the first and second experiments respectively Nearly cent percent of residues dissipated at 10 days after treatmentin the recommended dose of diafenthiuron 400 g ai haminus1 and the half life varied from 20 to 28 days with a waiting period of 55to 67 days in green capsules of cardamom The waiting period was 54 to 70 days in cured capsules of cardamom With harvestbeing the focal point for enforcement of residue tolerances the suggested waiting period of seven days is safe without the problemof pesticide residues in harvestable produce
1 Introduction
The pesticide use pattern in the present day situationshas led to pesticide residues in the harvestable produceresistance build-up by pests and eradication of nontargetswhich demands newer and safer pesticides with differ-ent modes of action Diafenthiuron (1-tert-butyl-3-(26-di-isopropyl thiourea)) is one such new insecticide which isthe only nonorganofluorine benzyl urea compound hav-ing novel insecticideacaricide activity acting selectively ongroup of insects and mites [1] by inhibiting or enhancingbiochemical sites such as respiration [2] Diafenthiuron isreported to be effective against whiteflies and leaf hoppersin brinjal [3 4] whiteflies aphids and thrips in tomato [5ndash7] thrips and mitesin chilies and tea [8 9] and all sucking
pests in cotton [10 11] Diafenthiuron is effective againstdiamondback moth (DBM) [12 13] shoot and capsule borerand thrips in cardamom [14] and it is gaining momentumnow in cardamom plantations Cardamom is an importantspice crop grown all over the world and one of the importantproducts fetching enormous foreign exchangeWith the strictlegislations enforced by the EPA cardamom capsules withpesticide residues have a chance of being rejected by thehitherto importing countries which in turn would have amajor say in foreign revenues Since diafenthiuron is effectiveagainst the pests of cardamom knowledge on the residuein the economic produce dissipation pattern and waitingperiod are necessary for its proper use
Diafenthiuron is a biologically inactive proinsecticidewhich needs transformation into active carbodiimide
Hindawi Publishing CorporationChromatography Research InternationalVolume 2014 Article ID 289747 8 pageshttpdxdoiorg1011552014289747
2 Chromatography Research International
O
iPr
iPr
NH C
S
NH(tBu)
O
iPr
iPr
C
[O] UV
N N(tBu) [S]+
Figure 1 Activation of diafenthiuron into carbodiimide form [17]
derivative In field conditions it is photochemically trans-formed to 3-(26-di isopropyl-4-phenoxyphenyl)-1-tert-butylcarbodiimide (DFCD) which is considered to be the agentresponsible for the biological activity [15 16] (see Figure1)
Direct photolysis by sunlight is the major degradationpathway of diafenthiuron [18] which is enhanced in humicacid water and aqueous acetone solutions [19] Diafenthiuronbehaves differently in plants as it exhibits strong translaminarand vapour activity Diafenthiuron is reported to rapidlydistribute into cuticular layer with a small portion per-sisting on the surface as dislodgeable residues Keum etal [19] extracted the dislodgeable residue of diafenthiuronby washing the leaves with Tween 80 Dichloromethane(DCM) and then with methanol partitioned with DCMand transferred into methanol to analyze in HPLC In plantmaterials diafenthiuron was analysed by extracting it inacetonitrile partitioned with hexane and analysed in HPLC[19]
Diafenthiuron was reported to have faster degradation inChinese cabbage which was fitted in first order kinetics [20]Different rates of degradation of diafenthiuron were reportedin cotton [15] Diafenthiuron is not approved by CentralInsecticide Board Registration Committee India (CIBampRC)for spray in brinjal in view of long waiting period of 10 daysbut approved for use in cardamom and subjected for fixingof tolerance limits [21] Thus the present study is undertakenwith the objective of detecting the harvest time residues anddissipation behaviour of diafenthiuron in fresh and curedcardamom capsules
2 Experimental
21 Chemicals and Reagents All the solvents were of analyti-cal grade obtained fromMerck India Diafenthiuron techni-cal (935 purity) obtained fromMs Syngenta India Limitedand formulation (diafenthiuron 50WP) obtained fromKrishiRasayan Exports Private Limited were used in the study The
reference standard of diafenthiuron (935 purity) was madeto 100 percent by transferring 107 g of the reference standardinto a 100mL volumetric flask which is then dissolved withdistilled acetone n-hexane (05 95) and then volume wasmade up to 100mL Then the flask was shaken well to geta homogenous solution of 1000120583gmLminus1 (stock solution)This solution was diluted to respective concentrations forfortification studies Formulation was used in field trialsafter dilution in tap water (pH 72ndash75) For extraction ofdiafenthiuron HPLC grade tertiary butyl methyl ether fromJT Baker USA and anhydrous potassium carbonate from sd-fine Chem Limited Mumbai were used
22 Preparation of Standard Solutions The solution forstandard preparation acetone n-hexane (05 95) vv wasprepared by adding 5mL of acetone and 95mL of n-hexaneLikewisemobile phase ofHPLC n-hexane and tertiary butylmethyl ether (65 35) vv was prepared by adding 65mL of n-hexane and 35mL of tertiary butyl methyl ether The cleanupsolution of 4 1 n-hexane and tertiary butyl methyl ether wasprepared by adding 40mL of n-hexane and 10mL of tertiarybutyl methyl ether
23 Field Experiments Following good agricultural prac-tices field experiments were conducted at two different loca-tions namely Bodimettu Bodi and the other DevarsholaGudalur India during 2005-2006 using Randomised BlockDesign Four cardamom clumps were taken for each replica-tion and each treatment was replicated thrice A control plotwhere no pesticide was sprayed was kept aside Diafenthi-uron 50 WP was sprayed 400 g ai haminus1 and 800 g ai haminus1using Knapsack sprayer Diafenthiuron is recommended forthree sprays at 30 days interval in cardamom for cardamomshoot and capsule borer Conogethes punctiferalis Gueneeandthrips Sciothrips cardamomi Ramk Hence three sprays weregiven at 30 days interval when the crop is at the stage offlowering to capsule formation
24 Sampling and Analytical Sample Preparation Maturedand uniform sized capsules were collected at random at thetime of harvest and at 0 (1 h) 1 3 7 15 21 and 30 daysafter treatment with the help of forceps for determination ofharvest time residues and dissipation after the third spray oncardamom The interval between the last spray and the firstharvest was 14 days in the first experiment and 17 days in thesecond experiment From each plot 150 g of green capsuleswas collected and from this a subsample of 25 g greencapsules in duplicate was taken for fresh sample analysisand transferred immediately into the sample container withacetonitrile in the field itself The remaining sample of 100 gwas divided into two and was cured under conventionalcuring chamber with a maximum temperature of 60ndash65∘Cmaintained for 24 h and used as cured samples for residueanalysis Thus a total of six samples were taken for analysisper treatment separately for green and cured capsules Theweights of the samples before and after curing were recordedfrom each plot in each sampling day to work out the residueson moisture free basis and curing loss
Chromatography Research International 3
25 Extraction
251 CardamomCapsules Extractionmixture was preparedwith 08 potassium carbonate and acetonitrile (1 4) vvby adding 25mL of potassium carbonate and 100mL ofacetonitrile Twenty five grams of cardamom was maceratedwith 125mL of extraction mixture by using homogenizerfor 2min The acetonitrile and potassium carbonate solutionwas filtered through Whatman number 42 filter paper ina Buchner funnel with mild vacuum suction The processwas repeated twice with 25mL of acetonitrile The combinedextract was evaporated and volume reduced up to 10mL byusing rotary flash vacuum evaporator (below 40∘C)
252 Soil The field soil samples collected at the time ofcollection of harvest time residues of capsules in both theexperiments were air dried grounded and sieved through100mm mesh 25 g of dry soil was placed into a 500mLErlenmeyer flask and 100mL acetonitrile and 25mL (08)potassium carbonate solution was added The flask was keptas such for 30 minutes with intermittent shakings Thecontents were filtered by suction through Whatman number42 filter paper in a Buchner funnel with mild vacuum Thesoil cake was againmixed and stirred with 25mL acetonitrileThe combined extract was reduced to 10mL in rotary flaskvacuum evaporator
26 Cleanup Procedure The concentrated extract (10mL)was taken in a 250mL separating funnel To this 35mLdistilled water two mL saturated sodium chloride and fivemL cleanup solution (as given in Section 22) were addedshaken well and allowed to separate the two layers Organiclayer was collected and evaporated to dryness the residuewas dissolved in 10mL of the HPLC grade n-hexane tertiarybutyl methyl ether (4 1) mixture and analyzed using HPLCin UV detector
27 Chromatographic Conditions The quantificationof residues was done using High Performance LiquidChromatography (HPLCmdashHitachi Model L 6200) equippedwith normal phase column of Si-10 (Micropak) of 30 cmtimes 4mm dimension HPLC grade n-hexane and tertiarybutyl methyl ether 65 35 were used as mobile phase witha flow rate of 05mLminminus1 [22] Injection was done with arheodyne loop injector with a volume of 20 120583L and detectedin L 4200UV detector at a wavelength of 256 nm Theamount of diafenthiuron in the sample was calculatedaccording to the equation based on the ratio of the peakareas of the standard and sample as follows
Residues =119867119904
119867stdtimes119882std119882119904
times119881119904
119860 sj (1)
where 119867119904
is the peak height of the sample 119867std is the peakheight of the standard 119882std is the weight of the standardinjected in ng119882
119904
is the weight of the sample in g 119881119904
is thevolume of the sample (final extract) in mL and 119860 sj is theAliquot of the sample injected in 120583L
28 Method Validation and Recovery Studies Theparametersaccuracy precision linearity and limits of detection (LOD)and quantification (LOQ) were considered for method vali-dation For linearity test different known concentrations ofdiafenthiuron (025 05 10 and 15 120583gmLminus1) were preparedin distilled acetone n-hexane (05 95) vv by diluting thestock solution Peak areas of each standard solution weremeasured after injecting in HPLC and a calibration curveplotted with concentration of standards versus area of therespective peaks obtained The accuracy of the methodwas determined by recovery tests using fresh cardamomcapsule and soil sample (25 g) taken from organically grownplantation To work out the recovery percent of the ana-lytical methodology different known concentrations (010025 050 and 10 120583g gminus1) of diafenthiuron were made byadding required quantity from 10 120583g gminus1 standard solution incardamom capsule Each concentration was taken in threereplications Samples were equilibrated for 1 h prior to extrac-tion and subsequently taken through the extraction andcleanup procedures described above The limit of detection(LOD 120583gmLminus1) was determined as the lowest concentrationgiving a response of three times the baseline noise definedfrom the analysis of control (untreated) sample The limit ofquantification (LOQ 120583gmLminus1) was determined as the lowestconcentration of diafenthiuron giving a response of 10 timesthe baseline noise [23]
3 Results and Discussion
31 Method Validation
311 Specificity Diafenthiuron was detected at 661min(retention time) (Figure 2) through the above said proce-dures Specificity was confirmed by injecting cardamomextract from cardamom not treated with diafenthiuron (con-trol) and found nomatrix peaks interferingwith the retentiontime of diafenthiuron
312 Linearity Linearity test was made by plotting a stan-dard graphcalibration curve with different standard concen-trations (025 05 10 and 15120583gmLminus1) versus the respectivearea of the peaks obtained The linear regression equationobtained was 119910 = 33288119909 + 4203 with 1198772 09887
313 Detection and Quantification Limits The limit of quan-tification was determined to be 005 120583gmLminus1 The limitof quantification of the analytical method in cardamomcapsules was 005120583g gminus1 considering 25 g weight samples forextraction and 5mL of sample extract The limit of detectionwas determined to be 001 120583gmLminus1 at a level of approximatelythree times the background noise of control injection aroundthe retention time of the peak of interest The minimumdetection limit (sensitivity) of the instrument was 025 120583g gminus1
314 Precision Repeatability and Recovery Percentage Themean recovery percentage was found to be 607 625 592and 593 in green capsules and 585 593 633 and 617in cured capsules respectively for 010 025 050 and100 120583g gminus1 in fortified levels The standard deviations of
4 Chromatography Research International
(min)
0605040302010
SP
500
8001011
661
(a) 025120583gmLminus1 of diafenthiuron standard
(min)
0605040302010
SP
525
800
661
(b) 05120583gmLminus1 of diafenthiuron standard
(min)
0605040302010
SP
090
800
660
(c) 10 120583gmLminus1 of diafenthiuron standard
(min)
0605040302010
SP
200
800
661
(d) 15120583gmLminus1 of diafenthiuron standard
Figure 2 Standard chromatogram of diafenthiuron in HPLC
recovery percentages for both green and cured capsulesare well below 3 and thus the repeatability of the methodis quite good The mean recovery was 6043 and 6070 forgreen and cured capsules respectively The mean percentrecovery of 606 was obtained in the present study on residueanalysis of diafenthiuron which is much lower than thatof the expected recovery of more than 80 percent whichis normally used for validation of residue protocols It ispresumed that the low recovery is due to the conversionof diafenthiuron into its metabolites namely N-[26-bis(1-methylethyl)-4-phenoxyphenyl]-N1015840-(11-dimethylethyl)ureaand N-[26-bis(1-methylethyl)-4-phenoxyphenyl]-N1015840-(11-dimethylethyl)carbodiimide [24] for which standards arenot available Thus the residue data obtained in the presentstudy is only for the parent compound and hence weightagewas given by multiplying the residues obtained with therecovery factor 165 to get the actual quantum of residue
32 Harvest Time Residues in Cardamom Capsules Theresidues of diafenthiuron in harvested capsules of cardamomboth green and cured were below detectable limit at the timeof first harvest after third spray Residues of diafenthiuronin the soil samples on 14 and 17 days after application ofdiafenthiuron on cardamom that is at the time of harvestwere found below detectable limit (BDL)
33 Residues in Green Capsules of Cardamom Half Lifeand Waiting Period The initial deposit on green capsulesin diafenthiuron 400 g ai haminus1 was 382 and 410 120583g gminus1in first and second field trials respectively The depositwas as high as 661 to 732 120583g gminus1 at the higher dose ofdiafenthiuron (800 g ai haminus1) (Tables 1 and 2) The residuesdissipated to below detectable level (BDL) at 15 DAT in boththe concentrations evaluated in two seasons The extent ofreduction in diafenthiuron residues at one DAT was 1439to 2068 percent in diafenthiuron 400 g ai haminus1 The half lifevalues varied from 195 to 282 days for diafenthiuron 400 g ai haminus1 and 342 to 361 days for 800 g ai haminus1 The
maximum residue level (MRL) value for diafenthiuron oncardamom is not available Maximum Residue Limits (MRL)for diafenthiuron was fixed by Australian Pesticides andVeterinary Management Authority on other commoditiesnamely cotton seed (02mg gminus1) peanut (01mg gminus1) and eggmeat milk and poultry (002mg gminus1) [25] Japanese FoodChemical Research Foundation has suggested an MRL valueof 03 120583g gminus1 for cabbage whereas 20120583g gminus1 for tea [25] Sincethe suggested MRL is of very wide range from 03 120583g gminus1 to20120583g gminus1 the tentativeMRLvalue of 05120583g gminus1 for bell pepperused by Syngenta India Ltd was used for arriving waitingperiods in cardamom in the present study The waitingperiod worked out was 550 to 669 days for diafenthiuron 400 g ai haminus1 and 1133 to 1140 days at 800 g ai haminus1
34 Residues in Cured Capsules of Cardamom Half Lifeand Waiting Period The extent of dissipation of residues atone DAT was 2233 to 2419 and 1907 to 2107 percent indiafenthiuron 400 g ai haminus1 and 800 g ai haminus1 respectivelyThe percent dissipation was more than 95 percent in diafen-thiuron 400 g ai haminus1 at 10 DAT and the residues dissipatedto BDL in 15DATThe half life was 178 days for diafenthiuron 400 g ai haminus1 in both the trials and 159 to 302 fordiafenthiuron 800 g ai haminus1 The waiting period workedout was 539 to 701 days for diafenthiuron 400 g ai haminus1The correlation coefficients (119903) of the calibration curvesderived for dissipation of diafenthiuron in cured capsules areabove 09 which shows best fit (Tables 1 and 2)
35 Residues of Diafenthiuron Estimated in Moisture FreeBasis The initial deposit of diafenthiuron residues workedout on moisture free basis was 1384 and 1483 120583g gminus1 indiafenthiuron 400 g ai haminus1 2399 and 2571 120583g gminus1 indiafenthiuron 800 g ai haminus1 in the first and second fieldtrials respectively The residues detected in cured capsuleswere slightly high when compared to green capsules But lowlevel of quinalphos residues was reported earlier in curedcapsules than green capsules [26] Though there will be loss
Chromatography Research International 5
Table1Diss
ipationof
diafenthiuroninoncapsules
ofcardam
ommdashEx
perim
entIB
odim
ettu
DAT
Green
capsules
Curedcapsules
Moistu
refre
ebasis
Diafenthiuron
400g
aihaminus1
Diafenthiuron
800g
aihaminus1
Diafenthiuron
400g
aiaminus1
Diafenthiuron
800g
aihaminus1
Diafenthiuron
400g
aihaminus1
Diafenthiuron
800g
aihaminus1
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
0382
mdash661
mdash496
mdash818
mdash1384
mdash2399
mdash1
303
2068
503
2392
376
2419
662
1907
1095
2086
1789
2543
318
45183
393
4053
220
5565
516
3685
647
5325
1401
4160
7019
9503
191
7110
069
8609
321
6075
068
9509
690
7125
10BD
L10000
089
8651
008
9839
202
7531
BDL
10000
325
8644
15BD
Lmdash
BDL
10000
BDL
10000
013
9841
BDL
mdashBD
Lmdash
21BD
Lmdash
BDL
mdashBD
Lmdash
BDL
mdashBD
Lmdash
BDL
mdashHalflife
(Days)
2815
360
617
7815
915
803636
Waitin
gperio
d(D
ays)
6693
11401
5390
10930
7134
1437
3
119903value
0932
0995
09747
0982
0983
0995
Regressio
nequatio
n
119884=
1948minus
0336119909
119884=
1888minus
0192119909
119884=
1801minus
0390119909
119884=
2388minus
0246119909
119884=
2831minus
0439119909
119884=3163minus
0241119909
BDLbelowdetectablelim
it
6 Chromatography Research International
Table2Dissipationof
diafenthiuroninoncapsules
ofcardam
ommdashEx
perim
entIIDevarshola
DAT
Green
capsules
Curedcapsules
Moistu
refre
ebasis
Diafenthiuron
400g
aihaminus1Diafenthiuron
800g
aihaminus1Diafenthiuron
400g
aihaminus1Diafenthiuron
800g
aihaminus1Diafenthiuron
400g
aihaminus1Diafenthiuron
800g
aihaminus1
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
0410
mdash732
mdash533
mdash840
mdash1483
mdash2571
mdash1
351
1439
581
2063
414
2233
663
2107
1198
1918
2070
1948
3203
5049
423
4221
312
4146
561
3321
721
5139
1483
4231
7086
7902
193
7363
113
7880
313
6274
323
7823
699
7281
10009
9780
092
8743
021
9606
124
8524
033
9788
327
8728
15BD
Lmdash
BDL
10000
BDL
10000
022
9726
BDL
10000
BDL
10000
21BD
Lmdash
BDL
mdashBD
Lmdash
BDL
mdashBD
Lmdash
BDL
mdashHalflife
(days)
1949
3416
1778
3015
2815
344
1
Waitin
gperio
d(days)
5500
1133
970
0611387
9168
17750
119903value
0958
0999
0972
0977
0954
0997
Regressio
nequatio
n
119884=
1657minus
0356119909
119884=
2001minus
0203119909
119884=
1843minus
0306119909
119884=
2318minus
0230119909
119884=
2917minus
0351119909
119884=3266minus
0201119909
BDLbelowdetectablelim
it
Chromatography Research International 7
0
1
2
3
4
0 1 3 7 10
Log
resid
ues (
ppm
)
Period (days)
Linear (green capsules)Linear (cured capsules)Linear (moisture free basis)
Figure 3Dynamics of diafenthiuron (008) residues in cardamomcapsulesmdashExperiment I
0
1
2
3
4
0 1 3 7 10 15
Log
resid
ues (
ppm
)
Period (days)
Linear (green capsules)Linear (cured capsules)Linear (moisture free basis)
Figure 4 Dynamics of diafenthiuron (008) residues in car-damom capsulesmdashExperiment II
of residues in curing process (steaming and garbling) thereduction in weight should also be taken into account Themoisture content in green cardamom is about 70 percentSo when the capsules are driedcured the residues presentin 25 g of green cardamom sample will get concentrated inabout 7 g of cured capsules The dissipation of diafenthiuronis slower than the moisture loss during curing Thus thehigher residues of diafenthiuron in cured capsules than greencapsules obtained in the present study might be due to themoisture loss and high reduction in weight during curing
The dissipation pattern of diafenthiuron in cardamomgreen and cured samples is shown in Figures 3 and 4 Thedissipation rate was much faster in the present study whichis in line with the reports of Keum et al [19] stating veryhigh rate of degradation in Chinese cabbage The waitingperiod (119905MRL) for diafenthiuron was arrived at 550ndash669days in green and 701ndash713 days in cured capsules at therecommended dose of 008 percent This is lower than thereports made for profenofos 005 percent on green (1176days) and cured capsules (1082 days) [27]Thewaiting periodof lambda cyhalothrin (80 ppm) in cardamom was reportedas 88 to 109 days [28]The waiting period was reported to beseven days in green capsules of cardamom for diafenthiuronsprayed at 600 g ai haminus1 [22]
As mentioned earlier diafenthiuron is not approvedby Central Insecticide Board and Registration Committee
(CIBampRC) for spray in brinjal in view of long waiting periodof 10 days but approved for use in cardamom and subjectedfor fixing of tolerance limits [21] Picking of cardamomcapsules is carried out at an interval of 20ndash30 days As harvestbeing the focal point for enforcement of residue tolerancesthe suggested waiting period of seven days is safe enough tocontain the cardamom pests with diafenthiuron without theproblem of pesticide residues in harvestable produce
In conclusion it is clear that diafenthiuron dissipated toa level below detectable by seven days after spraying Usuallycardamomcapsules are harvested at an interval of 20ndash30 daysSo spraying of diafenthiuron does not possess any risk ofresidues in the harvestable produce if sprayed at least sevendays before harvesting
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
References
[1] H P Streibert J Drabek and A Rindisbacher ldquoDiafenthiurona new type of acaricideinsecticide for the control of the suckingpest complex in cotton and other cropsrdquo in Proceedings ofBrighton Crop Protection Conference Pests and Diseases BCPCFarnham pp 25ndash32 Syrrey UK 1988
[2] I Ishaaya S Kontsedalov D Mazirov and A R HorowitzldquoBiorational agents in IPM and IRM programs for controllingagricultural pestsrdquo Universiteit Gent vol 66 pp 363ndash374 2001
[3] C Saradha and RMNachiappan ldquoEvaluation of diafenthiuron50WP (Polo) against whitefly Bemisia tabaci Genn (Aleyro-didae Homoptera) on Brinjal (Solanum mlongena)rdquo Pestologyvol 27 pp 12ndash14 2003
[4] J J Patel B H Patel P D Bhatt and A B Manghodia ldquoBio-efficacy of diafenthiuron 50 WP against sucking pests of bri-njal (Solanum melangena L)rdquo in Biodiversity and Insect PestManagement S Ignacimuthu and S Jayaraj Eds pp 57ndash58Narosa Publishing House New Delhi India 2006
[5] M A Javed and G A Matthews ldquoBioresidual and integratedpestmanagement status of a biorational agent and a novel insec-ticide against whitefly and its key parasitoidsrdquo InternationalJournal of Pest Management vol 48 no 1 pp 13ndash17 2002
[6] J R Scarpellani ldquoEffect of thiamethoxam and diafenthiuron tonymphs of whitefly Bemisia argentifolli on beansrdquo in Proceed-ings of the 21th International Conference of Entomology p 711Iguassu Falls Brazil August 2000
[7] A Noor Field evaluation of newer insecticides against suckingpests infesting in chillies in Western Rajasthan [PhD thesis]Department of Entomology Agricultural Research StationRAU campus Mandor Jodhpur 2001
[8] M H Tatagar H D Mohankumar R K Mesta and MShivaprasad ldquoBioefficacy of new molecules Pegasus 50 WP tochilli thrips Scirtothrips dorsalis (Hood) and mites Polyphago-tarsonemus latus (Banks)rdquo Pestology vol 36 no 2 pp 19ndash212012
[9] UPASI Seventy Nine Annual Report Edited by N Muraleedha-ran and R Rajkumar UPASI Tea Research Found 2005
[10] R Sudhakaran P Rajakumari and A Mohandhas ldquoEvaluationof newer insecticides Match 5 EC and Polo 50 SC on the controlof insect pests on cottonrdquo Pestology vol 19 pp 14ndash18 1995
8 Chromatography Research International
[11] K R Kranthi S Kranthi et al ldquoIRM-Revolutionising cottonpestmanagement in IndiardquoResistant PestManagement Newslet-ter vol 14 pp 33ndash36 2004
[12] I Ishaaya Z Mendelson and A R Horowitz ldquoToxicity andgrowth-suppression exerted by diafenthiuron in the sweet-potatowhiteflyBemisia tabacirdquoPhytoparasitica vol 21 pp 199ndash204 1993
[13] S Lingappa K Basavanagoud K A Kulkarni S P Roopaand D N Kambrekar ldquoThreat to vegetable production by dia-mondback moth and its management strategiesrdquo in DiseaseManagement in Fruits and Vegetables pp 357ndash396 SpringerAmsterdam The Netherlands 2004
[14] J Stanley S Chandrasekaran G Preetha and S KuttalamldquoToxicity of diafenthiuron to honey bees in laboratory semi-field and field conditionsrdquo PestManagement Science vol 66 no5 pp 505ndash510 2010
[15] J Drabek M Boger J Ehrenfreund et al ldquoNew thioureasas insecticidesrdquo in Recent Advances in the Chemistry of InsectControl II C Crobie Ed vol 79 of Special Publication pp 170ndash183 Royal Society of Chemistry Cambridge UK 1992
[16] H A Kadir and C O Knowles ldquoToxicological studies of thethiourea diafenthiuron in diamondback moths and two spottedspider mites and bulb mitesrdquo Journal of Economic Entomologyvol 84 pp 780ndash784 1991
[17] IUPACDetection and Significance of ActiveMetabolites of Agro-chemicals and Related Xenobiotics in Animals vol 67 of Editedby RM Hollingworth N Kurihara J Miyamoto S Otto andGD Paulson International Union of Pure and Applied Chem-istry 1995
[18] H Kayser and P Eilinger ldquoMetabolism of diafenthiuron bymicrosomal oxidation procide activation and inactivation asmechanisms contributing to selectivityrdquo Pest Management Sci-ence vol 57 pp 975ndash980 2001
[19] Y-S Keum J-H Kim Y-W Kim K Kim and Q X Li ldquoPhoto-degradation of diafenthiuron in waterrdquo Pest Management Sci-ence vol 58 no 5 pp 496ndash502 2002
[20] Y S Keum K H Liu J S Seo et al ldquoDissipation of foliarresidues of diafenthiuron and its metabolitesrdquo Bulletin of Envi-ronmental Contamination and Toxicology vol 68 no 6 pp845ndash851 2002
[21] CIBampRC ldquoCentral Insecticide Board andRegistrationCommit-teerdquo 2006 httpwwwcibrcnicin267rcdoc
[22] D Rajabaskar and A Regupathy ldquoPersistence of diafenthiuronin cardamomrdquo Pesticide Research Journal vol 20 pp 247ndash2492008
[23] S Navickiene A Aquino and D S S Bezerra ldquoA matrix solid-phase dispersion method for the extraction of seven pesticidesfrom mango and papayardquo Journal of Chromatographic Sciencevol 48 no 9 pp 750ndash754 2010
[24] APVMA ldquoThe standard MRL in food and animal feed stuffMay 2007 Maximum residue levels of Agricultural and Veteri-nary chemicals and associated substances in food commodi-tiesrdquo 2007 httpwwwapvmagovauresidues
[25] Table of MRLs for Agricultural Chemicals ldquoThe Japan FoodChemical Research Foundationrdquo 2010 httpwwwffcrorjp
[26] S Valarmathi and A Regupathy ldquoEvaluation of two ecofriendlyformulations of quinalphos aqua flow (AF) and colloidal sus-pension (CS) on cardamomresiduesrdquo in 14th International PlantProtection Congress (IPPC rsquo99) Jerusalem Israel July 1999
[27] D Rajabaskar Studies on the evaluation of IPMmodules againstConogethes punctiferalis Guenee and Sciothrips cardamomi
Ramk on cardamom [PhD thesis] Tamil Nadu AgriculturalUniversity Coimbatore India 2003
[28] A Regupathy R S S Kumar D Rajabaskar and K ChozhanldquoDetermination of residues of profenophos in cardamomrdquo inProceedings of National Seminar on Resource Management inPlant Protection during Twenty First Century Hyderabad India2002
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
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Carbohydrate Chemistry
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Advances in
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Analytical Methods in Chemistry
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Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
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The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
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Journal of
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Analytical ChemistryInternational Journal of
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Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
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CatalystsJournal of
2 Chromatography Research International
O
iPr
iPr
NH C
S
NH(tBu)
O
iPr
iPr
C
[O] UV
N N(tBu) [S]+
Figure 1 Activation of diafenthiuron into carbodiimide form [17]
derivative In field conditions it is photochemically trans-formed to 3-(26-di isopropyl-4-phenoxyphenyl)-1-tert-butylcarbodiimide (DFCD) which is considered to be the agentresponsible for the biological activity [15 16] (see Figure1)
Direct photolysis by sunlight is the major degradationpathway of diafenthiuron [18] which is enhanced in humicacid water and aqueous acetone solutions [19] Diafenthiuronbehaves differently in plants as it exhibits strong translaminarand vapour activity Diafenthiuron is reported to rapidlydistribute into cuticular layer with a small portion per-sisting on the surface as dislodgeable residues Keum etal [19] extracted the dislodgeable residue of diafenthiuronby washing the leaves with Tween 80 Dichloromethane(DCM) and then with methanol partitioned with DCMand transferred into methanol to analyze in HPLC In plantmaterials diafenthiuron was analysed by extracting it inacetonitrile partitioned with hexane and analysed in HPLC[19]
Diafenthiuron was reported to have faster degradation inChinese cabbage which was fitted in first order kinetics [20]Different rates of degradation of diafenthiuron were reportedin cotton [15] Diafenthiuron is not approved by CentralInsecticide Board Registration Committee India (CIBampRC)for spray in brinjal in view of long waiting period of 10 daysbut approved for use in cardamom and subjected for fixingof tolerance limits [21] Thus the present study is undertakenwith the objective of detecting the harvest time residues anddissipation behaviour of diafenthiuron in fresh and curedcardamom capsules
2 Experimental
21 Chemicals and Reagents All the solvents were of analyti-cal grade obtained fromMerck India Diafenthiuron techni-cal (935 purity) obtained fromMs Syngenta India Limitedand formulation (diafenthiuron 50WP) obtained fromKrishiRasayan Exports Private Limited were used in the study The
reference standard of diafenthiuron (935 purity) was madeto 100 percent by transferring 107 g of the reference standardinto a 100mL volumetric flask which is then dissolved withdistilled acetone n-hexane (05 95) and then volume wasmade up to 100mL Then the flask was shaken well to geta homogenous solution of 1000120583gmLminus1 (stock solution)This solution was diluted to respective concentrations forfortification studies Formulation was used in field trialsafter dilution in tap water (pH 72ndash75) For extraction ofdiafenthiuron HPLC grade tertiary butyl methyl ether fromJT Baker USA and anhydrous potassium carbonate from sd-fine Chem Limited Mumbai were used
22 Preparation of Standard Solutions The solution forstandard preparation acetone n-hexane (05 95) vv wasprepared by adding 5mL of acetone and 95mL of n-hexaneLikewisemobile phase ofHPLC n-hexane and tertiary butylmethyl ether (65 35) vv was prepared by adding 65mL of n-hexane and 35mL of tertiary butyl methyl ether The cleanupsolution of 4 1 n-hexane and tertiary butyl methyl ether wasprepared by adding 40mL of n-hexane and 10mL of tertiarybutyl methyl ether
23 Field Experiments Following good agricultural prac-tices field experiments were conducted at two different loca-tions namely Bodimettu Bodi and the other DevarsholaGudalur India during 2005-2006 using Randomised BlockDesign Four cardamom clumps were taken for each replica-tion and each treatment was replicated thrice A control plotwhere no pesticide was sprayed was kept aside Diafenthi-uron 50 WP was sprayed 400 g ai haminus1 and 800 g ai haminus1using Knapsack sprayer Diafenthiuron is recommended forthree sprays at 30 days interval in cardamom for cardamomshoot and capsule borer Conogethes punctiferalis Gueneeandthrips Sciothrips cardamomi Ramk Hence three sprays weregiven at 30 days interval when the crop is at the stage offlowering to capsule formation
24 Sampling and Analytical Sample Preparation Maturedand uniform sized capsules were collected at random at thetime of harvest and at 0 (1 h) 1 3 7 15 21 and 30 daysafter treatment with the help of forceps for determination ofharvest time residues and dissipation after the third spray oncardamom The interval between the last spray and the firstharvest was 14 days in the first experiment and 17 days in thesecond experiment From each plot 150 g of green capsuleswas collected and from this a subsample of 25 g greencapsules in duplicate was taken for fresh sample analysisand transferred immediately into the sample container withacetonitrile in the field itself The remaining sample of 100 gwas divided into two and was cured under conventionalcuring chamber with a maximum temperature of 60ndash65∘Cmaintained for 24 h and used as cured samples for residueanalysis Thus a total of six samples were taken for analysisper treatment separately for green and cured capsules Theweights of the samples before and after curing were recordedfrom each plot in each sampling day to work out the residueson moisture free basis and curing loss
Chromatography Research International 3
25 Extraction
251 CardamomCapsules Extractionmixture was preparedwith 08 potassium carbonate and acetonitrile (1 4) vvby adding 25mL of potassium carbonate and 100mL ofacetonitrile Twenty five grams of cardamom was maceratedwith 125mL of extraction mixture by using homogenizerfor 2min The acetonitrile and potassium carbonate solutionwas filtered through Whatman number 42 filter paper ina Buchner funnel with mild vacuum suction The processwas repeated twice with 25mL of acetonitrile The combinedextract was evaporated and volume reduced up to 10mL byusing rotary flash vacuum evaporator (below 40∘C)
252 Soil The field soil samples collected at the time ofcollection of harvest time residues of capsules in both theexperiments were air dried grounded and sieved through100mm mesh 25 g of dry soil was placed into a 500mLErlenmeyer flask and 100mL acetonitrile and 25mL (08)potassium carbonate solution was added The flask was keptas such for 30 minutes with intermittent shakings Thecontents were filtered by suction through Whatman number42 filter paper in a Buchner funnel with mild vacuum Thesoil cake was againmixed and stirred with 25mL acetonitrileThe combined extract was reduced to 10mL in rotary flaskvacuum evaporator
26 Cleanup Procedure The concentrated extract (10mL)was taken in a 250mL separating funnel To this 35mLdistilled water two mL saturated sodium chloride and fivemL cleanup solution (as given in Section 22) were addedshaken well and allowed to separate the two layers Organiclayer was collected and evaporated to dryness the residuewas dissolved in 10mL of the HPLC grade n-hexane tertiarybutyl methyl ether (4 1) mixture and analyzed using HPLCin UV detector
27 Chromatographic Conditions The quantificationof residues was done using High Performance LiquidChromatography (HPLCmdashHitachi Model L 6200) equippedwith normal phase column of Si-10 (Micropak) of 30 cmtimes 4mm dimension HPLC grade n-hexane and tertiarybutyl methyl ether 65 35 were used as mobile phase witha flow rate of 05mLminminus1 [22] Injection was done with arheodyne loop injector with a volume of 20 120583L and detectedin L 4200UV detector at a wavelength of 256 nm Theamount of diafenthiuron in the sample was calculatedaccording to the equation based on the ratio of the peakareas of the standard and sample as follows
Residues =119867119904
119867stdtimes119882std119882119904
times119881119904
119860 sj (1)
where 119867119904
is the peak height of the sample 119867std is the peakheight of the standard 119882std is the weight of the standardinjected in ng119882
119904
is the weight of the sample in g 119881119904
is thevolume of the sample (final extract) in mL and 119860 sj is theAliquot of the sample injected in 120583L
28 Method Validation and Recovery Studies Theparametersaccuracy precision linearity and limits of detection (LOD)and quantification (LOQ) were considered for method vali-dation For linearity test different known concentrations ofdiafenthiuron (025 05 10 and 15 120583gmLminus1) were preparedin distilled acetone n-hexane (05 95) vv by diluting thestock solution Peak areas of each standard solution weremeasured after injecting in HPLC and a calibration curveplotted with concentration of standards versus area of therespective peaks obtained The accuracy of the methodwas determined by recovery tests using fresh cardamomcapsule and soil sample (25 g) taken from organically grownplantation To work out the recovery percent of the ana-lytical methodology different known concentrations (010025 050 and 10 120583g gminus1) of diafenthiuron were made byadding required quantity from 10 120583g gminus1 standard solution incardamom capsule Each concentration was taken in threereplications Samples were equilibrated for 1 h prior to extrac-tion and subsequently taken through the extraction andcleanup procedures described above The limit of detection(LOD 120583gmLminus1) was determined as the lowest concentrationgiving a response of three times the baseline noise definedfrom the analysis of control (untreated) sample The limit ofquantification (LOQ 120583gmLminus1) was determined as the lowestconcentration of diafenthiuron giving a response of 10 timesthe baseline noise [23]
3 Results and Discussion
31 Method Validation
311 Specificity Diafenthiuron was detected at 661min(retention time) (Figure 2) through the above said proce-dures Specificity was confirmed by injecting cardamomextract from cardamom not treated with diafenthiuron (con-trol) and found nomatrix peaks interferingwith the retentiontime of diafenthiuron
312 Linearity Linearity test was made by plotting a stan-dard graphcalibration curve with different standard concen-trations (025 05 10 and 15120583gmLminus1) versus the respectivearea of the peaks obtained The linear regression equationobtained was 119910 = 33288119909 + 4203 with 1198772 09887
313 Detection and Quantification Limits The limit of quan-tification was determined to be 005 120583gmLminus1 The limitof quantification of the analytical method in cardamomcapsules was 005120583g gminus1 considering 25 g weight samples forextraction and 5mL of sample extract The limit of detectionwas determined to be 001 120583gmLminus1 at a level of approximatelythree times the background noise of control injection aroundthe retention time of the peak of interest The minimumdetection limit (sensitivity) of the instrument was 025 120583g gminus1
314 Precision Repeatability and Recovery Percentage Themean recovery percentage was found to be 607 625 592and 593 in green capsules and 585 593 633 and 617in cured capsules respectively for 010 025 050 and100 120583g gminus1 in fortified levels The standard deviations of
4 Chromatography Research International
(min)
0605040302010
SP
500
8001011
661
(a) 025120583gmLminus1 of diafenthiuron standard
(min)
0605040302010
SP
525
800
661
(b) 05120583gmLminus1 of diafenthiuron standard
(min)
0605040302010
SP
090
800
660
(c) 10 120583gmLminus1 of diafenthiuron standard
(min)
0605040302010
SP
200
800
661
(d) 15120583gmLminus1 of diafenthiuron standard
Figure 2 Standard chromatogram of diafenthiuron in HPLC
recovery percentages for both green and cured capsulesare well below 3 and thus the repeatability of the methodis quite good The mean recovery was 6043 and 6070 forgreen and cured capsules respectively The mean percentrecovery of 606 was obtained in the present study on residueanalysis of diafenthiuron which is much lower than thatof the expected recovery of more than 80 percent whichis normally used for validation of residue protocols It ispresumed that the low recovery is due to the conversionof diafenthiuron into its metabolites namely N-[26-bis(1-methylethyl)-4-phenoxyphenyl]-N1015840-(11-dimethylethyl)ureaand N-[26-bis(1-methylethyl)-4-phenoxyphenyl]-N1015840-(11-dimethylethyl)carbodiimide [24] for which standards arenot available Thus the residue data obtained in the presentstudy is only for the parent compound and hence weightagewas given by multiplying the residues obtained with therecovery factor 165 to get the actual quantum of residue
32 Harvest Time Residues in Cardamom Capsules Theresidues of diafenthiuron in harvested capsules of cardamomboth green and cured were below detectable limit at the timeof first harvest after third spray Residues of diafenthiuronin the soil samples on 14 and 17 days after application ofdiafenthiuron on cardamom that is at the time of harvestwere found below detectable limit (BDL)
33 Residues in Green Capsules of Cardamom Half Lifeand Waiting Period The initial deposit on green capsulesin diafenthiuron 400 g ai haminus1 was 382 and 410 120583g gminus1in first and second field trials respectively The depositwas as high as 661 to 732 120583g gminus1 at the higher dose ofdiafenthiuron (800 g ai haminus1) (Tables 1 and 2) The residuesdissipated to below detectable level (BDL) at 15 DAT in boththe concentrations evaluated in two seasons The extent ofreduction in diafenthiuron residues at one DAT was 1439to 2068 percent in diafenthiuron 400 g ai haminus1 The half lifevalues varied from 195 to 282 days for diafenthiuron 400 g ai haminus1 and 342 to 361 days for 800 g ai haminus1 The
maximum residue level (MRL) value for diafenthiuron oncardamom is not available Maximum Residue Limits (MRL)for diafenthiuron was fixed by Australian Pesticides andVeterinary Management Authority on other commoditiesnamely cotton seed (02mg gminus1) peanut (01mg gminus1) and eggmeat milk and poultry (002mg gminus1) [25] Japanese FoodChemical Research Foundation has suggested an MRL valueof 03 120583g gminus1 for cabbage whereas 20120583g gminus1 for tea [25] Sincethe suggested MRL is of very wide range from 03 120583g gminus1 to20120583g gminus1 the tentativeMRLvalue of 05120583g gminus1 for bell pepperused by Syngenta India Ltd was used for arriving waitingperiods in cardamom in the present study The waitingperiod worked out was 550 to 669 days for diafenthiuron 400 g ai haminus1 and 1133 to 1140 days at 800 g ai haminus1
34 Residues in Cured Capsules of Cardamom Half Lifeand Waiting Period The extent of dissipation of residues atone DAT was 2233 to 2419 and 1907 to 2107 percent indiafenthiuron 400 g ai haminus1 and 800 g ai haminus1 respectivelyThe percent dissipation was more than 95 percent in diafen-thiuron 400 g ai haminus1 at 10 DAT and the residues dissipatedto BDL in 15DATThe half life was 178 days for diafenthiuron 400 g ai haminus1 in both the trials and 159 to 302 fordiafenthiuron 800 g ai haminus1 The waiting period workedout was 539 to 701 days for diafenthiuron 400 g ai haminus1The correlation coefficients (119903) of the calibration curvesderived for dissipation of diafenthiuron in cured capsules areabove 09 which shows best fit (Tables 1 and 2)
35 Residues of Diafenthiuron Estimated in Moisture FreeBasis The initial deposit of diafenthiuron residues workedout on moisture free basis was 1384 and 1483 120583g gminus1 indiafenthiuron 400 g ai haminus1 2399 and 2571 120583g gminus1 indiafenthiuron 800 g ai haminus1 in the first and second fieldtrials respectively The residues detected in cured capsuleswere slightly high when compared to green capsules But lowlevel of quinalphos residues was reported earlier in curedcapsules than green capsules [26] Though there will be loss
Chromatography Research International 5
Table1Diss
ipationof
diafenthiuroninoncapsules
ofcardam
ommdashEx
perim
entIB
odim
ettu
DAT
Green
capsules
Curedcapsules
Moistu
refre
ebasis
Diafenthiuron
400g
aihaminus1
Diafenthiuron
800g
aihaminus1
Diafenthiuron
400g
aiaminus1
Diafenthiuron
800g
aihaminus1
Diafenthiuron
400g
aihaminus1
Diafenthiuron
800g
aihaminus1
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
0382
mdash661
mdash496
mdash818
mdash1384
mdash2399
mdash1
303
2068
503
2392
376
2419
662
1907
1095
2086
1789
2543
318
45183
393
4053
220
5565
516
3685
647
5325
1401
4160
7019
9503
191
7110
069
8609
321
6075
068
9509
690
7125
10BD
L10000
089
8651
008
9839
202
7531
BDL
10000
325
8644
15BD
Lmdash
BDL
10000
BDL
10000
013
9841
BDL
mdashBD
Lmdash
21BD
Lmdash
BDL
mdashBD
Lmdash
BDL
mdashBD
Lmdash
BDL
mdashHalflife
(Days)
2815
360
617
7815
915
803636
Waitin
gperio
d(D
ays)
6693
11401
5390
10930
7134
1437
3
119903value
0932
0995
09747
0982
0983
0995
Regressio
nequatio
n
119884=
1948minus
0336119909
119884=
1888minus
0192119909
119884=
1801minus
0390119909
119884=
2388minus
0246119909
119884=
2831minus
0439119909
119884=3163minus
0241119909
BDLbelowdetectablelim
it
6 Chromatography Research International
Table2Dissipationof
diafenthiuroninoncapsules
ofcardam
ommdashEx
perim
entIIDevarshola
DAT
Green
capsules
Curedcapsules
Moistu
refre
ebasis
Diafenthiuron
400g
aihaminus1Diafenthiuron
800g
aihaminus1Diafenthiuron
400g
aihaminus1Diafenthiuron
800g
aihaminus1Diafenthiuron
400g
aihaminus1Diafenthiuron
800g
aihaminus1
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
0410
mdash732
mdash533
mdash840
mdash1483
mdash2571
mdash1
351
1439
581
2063
414
2233
663
2107
1198
1918
2070
1948
3203
5049
423
4221
312
4146
561
3321
721
5139
1483
4231
7086
7902
193
7363
113
7880
313
6274
323
7823
699
7281
10009
9780
092
8743
021
9606
124
8524
033
9788
327
8728
15BD
Lmdash
BDL
10000
BDL
10000
022
9726
BDL
10000
BDL
10000
21BD
Lmdash
BDL
mdashBD
Lmdash
BDL
mdashBD
Lmdash
BDL
mdashHalflife
(days)
1949
3416
1778
3015
2815
344
1
Waitin
gperio
d(days)
5500
1133
970
0611387
9168
17750
119903value
0958
0999
0972
0977
0954
0997
Regressio
nequatio
n
119884=
1657minus
0356119909
119884=
2001minus
0203119909
119884=
1843minus
0306119909
119884=
2318minus
0230119909
119884=
2917minus
0351119909
119884=3266minus
0201119909
BDLbelowdetectablelim
it
Chromatography Research International 7
0
1
2
3
4
0 1 3 7 10
Log
resid
ues (
ppm
)
Period (days)
Linear (green capsules)Linear (cured capsules)Linear (moisture free basis)
Figure 3Dynamics of diafenthiuron (008) residues in cardamomcapsulesmdashExperiment I
0
1
2
3
4
0 1 3 7 10 15
Log
resid
ues (
ppm
)
Period (days)
Linear (green capsules)Linear (cured capsules)Linear (moisture free basis)
Figure 4 Dynamics of diafenthiuron (008) residues in car-damom capsulesmdashExperiment II
of residues in curing process (steaming and garbling) thereduction in weight should also be taken into account Themoisture content in green cardamom is about 70 percentSo when the capsules are driedcured the residues presentin 25 g of green cardamom sample will get concentrated inabout 7 g of cured capsules The dissipation of diafenthiuronis slower than the moisture loss during curing Thus thehigher residues of diafenthiuron in cured capsules than greencapsules obtained in the present study might be due to themoisture loss and high reduction in weight during curing
The dissipation pattern of diafenthiuron in cardamomgreen and cured samples is shown in Figures 3 and 4 Thedissipation rate was much faster in the present study whichis in line with the reports of Keum et al [19] stating veryhigh rate of degradation in Chinese cabbage The waitingperiod (119905MRL) for diafenthiuron was arrived at 550ndash669days in green and 701ndash713 days in cured capsules at therecommended dose of 008 percent This is lower than thereports made for profenofos 005 percent on green (1176days) and cured capsules (1082 days) [27]Thewaiting periodof lambda cyhalothrin (80 ppm) in cardamom was reportedas 88 to 109 days [28]The waiting period was reported to beseven days in green capsules of cardamom for diafenthiuronsprayed at 600 g ai haminus1 [22]
As mentioned earlier diafenthiuron is not approvedby Central Insecticide Board and Registration Committee
(CIBampRC) for spray in brinjal in view of long waiting periodof 10 days but approved for use in cardamom and subjectedfor fixing of tolerance limits [21] Picking of cardamomcapsules is carried out at an interval of 20ndash30 days As harvestbeing the focal point for enforcement of residue tolerancesthe suggested waiting period of seven days is safe enough tocontain the cardamom pests with diafenthiuron without theproblem of pesticide residues in harvestable produce
In conclusion it is clear that diafenthiuron dissipated toa level below detectable by seven days after spraying Usuallycardamomcapsules are harvested at an interval of 20ndash30 daysSo spraying of diafenthiuron does not possess any risk ofresidues in the harvestable produce if sprayed at least sevendays before harvesting
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
References
[1] H P Streibert J Drabek and A Rindisbacher ldquoDiafenthiurona new type of acaricideinsecticide for the control of the suckingpest complex in cotton and other cropsrdquo in Proceedings ofBrighton Crop Protection Conference Pests and Diseases BCPCFarnham pp 25ndash32 Syrrey UK 1988
[2] I Ishaaya S Kontsedalov D Mazirov and A R HorowitzldquoBiorational agents in IPM and IRM programs for controllingagricultural pestsrdquo Universiteit Gent vol 66 pp 363ndash374 2001
[3] C Saradha and RMNachiappan ldquoEvaluation of diafenthiuron50WP (Polo) against whitefly Bemisia tabaci Genn (Aleyro-didae Homoptera) on Brinjal (Solanum mlongena)rdquo Pestologyvol 27 pp 12ndash14 2003
[4] J J Patel B H Patel P D Bhatt and A B Manghodia ldquoBio-efficacy of diafenthiuron 50 WP against sucking pests of bri-njal (Solanum melangena L)rdquo in Biodiversity and Insect PestManagement S Ignacimuthu and S Jayaraj Eds pp 57ndash58Narosa Publishing House New Delhi India 2006
[5] M A Javed and G A Matthews ldquoBioresidual and integratedpestmanagement status of a biorational agent and a novel insec-ticide against whitefly and its key parasitoidsrdquo InternationalJournal of Pest Management vol 48 no 1 pp 13ndash17 2002
[6] J R Scarpellani ldquoEffect of thiamethoxam and diafenthiuron tonymphs of whitefly Bemisia argentifolli on beansrdquo in Proceed-ings of the 21th International Conference of Entomology p 711Iguassu Falls Brazil August 2000
[7] A Noor Field evaluation of newer insecticides against suckingpests infesting in chillies in Western Rajasthan [PhD thesis]Department of Entomology Agricultural Research StationRAU campus Mandor Jodhpur 2001
[8] M H Tatagar H D Mohankumar R K Mesta and MShivaprasad ldquoBioefficacy of new molecules Pegasus 50 WP tochilli thrips Scirtothrips dorsalis (Hood) and mites Polyphago-tarsonemus latus (Banks)rdquo Pestology vol 36 no 2 pp 19ndash212012
[9] UPASI Seventy Nine Annual Report Edited by N Muraleedha-ran and R Rajkumar UPASI Tea Research Found 2005
[10] R Sudhakaran P Rajakumari and A Mohandhas ldquoEvaluationof newer insecticides Match 5 EC and Polo 50 SC on the controlof insect pests on cottonrdquo Pestology vol 19 pp 14ndash18 1995
8 Chromatography Research International
[11] K R Kranthi S Kranthi et al ldquoIRM-Revolutionising cottonpestmanagement in IndiardquoResistant PestManagement Newslet-ter vol 14 pp 33ndash36 2004
[12] I Ishaaya Z Mendelson and A R Horowitz ldquoToxicity andgrowth-suppression exerted by diafenthiuron in the sweet-potatowhiteflyBemisia tabacirdquoPhytoparasitica vol 21 pp 199ndash204 1993
[13] S Lingappa K Basavanagoud K A Kulkarni S P Roopaand D N Kambrekar ldquoThreat to vegetable production by dia-mondback moth and its management strategiesrdquo in DiseaseManagement in Fruits and Vegetables pp 357ndash396 SpringerAmsterdam The Netherlands 2004
[14] J Stanley S Chandrasekaran G Preetha and S KuttalamldquoToxicity of diafenthiuron to honey bees in laboratory semi-field and field conditionsrdquo PestManagement Science vol 66 no5 pp 505ndash510 2010
[15] J Drabek M Boger J Ehrenfreund et al ldquoNew thioureasas insecticidesrdquo in Recent Advances in the Chemistry of InsectControl II C Crobie Ed vol 79 of Special Publication pp 170ndash183 Royal Society of Chemistry Cambridge UK 1992
[16] H A Kadir and C O Knowles ldquoToxicological studies of thethiourea diafenthiuron in diamondback moths and two spottedspider mites and bulb mitesrdquo Journal of Economic Entomologyvol 84 pp 780ndash784 1991
[17] IUPACDetection and Significance of ActiveMetabolites of Agro-chemicals and Related Xenobiotics in Animals vol 67 of Editedby RM Hollingworth N Kurihara J Miyamoto S Otto andGD Paulson International Union of Pure and Applied Chem-istry 1995
[18] H Kayser and P Eilinger ldquoMetabolism of diafenthiuron bymicrosomal oxidation procide activation and inactivation asmechanisms contributing to selectivityrdquo Pest Management Sci-ence vol 57 pp 975ndash980 2001
[19] Y-S Keum J-H Kim Y-W Kim K Kim and Q X Li ldquoPhoto-degradation of diafenthiuron in waterrdquo Pest Management Sci-ence vol 58 no 5 pp 496ndash502 2002
[20] Y S Keum K H Liu J S Seo et al ldquoDissipation of foliarresidues of diafenthiuron and its metabolitesrdquo Bulletin of Envi-ronmental Contamination and Toxicology vol 68 no 6 pp845ndash851 2002
[21] CIBampRC ldquoCentral Insecticide Board andRegistrationCommit-teerdquo 2006 httpwwwcibrcnicin267rcdoc
[22] D Rajabaskar and A Regupathy ldquoPersistence of diafenthiuronin cardamomrdquo Pesticide Research Journal vol 20 pp 247ndash2492008
[23] S Navickiene A Aquino and D S S Bezerra ldquoA matrix solid-phase dispersion method for the extraction of seven pesticidesfrom mango and papayardquo Journal of Chromatographic Sciencevol 48 no 9 pp 750ndash754 2010
[24] APVMA ldquoThe standard MRL in food and animal feed stuffMay 2007 Maximum residue levels of Agricultural and Veteri-nary chemicals and associated substances in food commodi-tiesrdquo 2007 httpwwwapvmagovauresidues
[25] Table of MRLs for Agricultural Chemicals ldquoThe Japan FoodChemical Research Foundationrdquo 2010 httpwwwffcrorjp
[26] S Valarmathi and A Regupathy ldquoEvaluation of two ecofriendlyformulations of quinalphos aqua flow (AF) and colloidal sus-pension (CS) on cardamomresiduesrdquo in 14th International PlantProtection Congress (IPPC rsquo99) Jerusalem Israel July 1999
[27] D Rajabaskar Studies on the evaluation of IPMmodules againstConogethes punctiferalis Guenee and Sciothrips cardamomi
Ramk on cardamom [PhD thesis] Tamil Nadu AgriculturalUniversity Coimbatore India 2003
[28] A Regupathy R S S Kumar D Rajabaskar and K ChozhanldquoDetermination of residues of profenophos in cardamomrdquo inProceedings of National Seminar on Resource Management inPlant Protection during Twenty First Century Hyderabad India2002
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
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International Journal ofPhotoenergy
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Carbohydrate Chemistry
International Journal of
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Journal of
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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
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Analytical Methods in Chemistry
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Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
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The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
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Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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CatalystsJournal of
Chromatography Research International 3
25 Extraction
251 CardamomCapsules Extractionmixture was preparedwith 08 potassium carbonate and acetonitrile (1 4) vvby adding 25mL of potassium carbonate and 100mL ofacetonitrile Twenty five grams of cardamom was maceratedwith 125mL of extraction mixture by using homogenizerfor 2min The acetonitrile and potassium carbonate solutionwas filtered through Whatman number 42 filter paper ina Buchner funnel with mild vacuum suction The processwas repeated twice with 25mL of acetonitrile The combinedextract was evaporated and volume reduced up to 10mL byusing rotary flash vacuum evaporator (below 40∘C)
252 Soil The field soil samples collected at the time ofcollection of harvest time residues of capsules in both theexperiments were air dried grounded and sieved through100mm mesh 25 g of dry soil was placed into a 500mLErlenmeyer flask and 100mL acetonitrile and 25mL (08)potassium carbonate solution was added The flask was keptas such for 30 minutes with intermittent shakings Thecontents were filtered by suction through Whatman number42 filter paper in a Buchner funnel with mild vacuum Thesoil cake was againmixed and stirred with 25mL acetonitrileThe combined extract was reduced to 10mL in rotary flaskvacuum evaporator
26 Cleanup Procedure The concentrated extract (10mL)was taken in a 250mL separating funnel To this 35mLdistilled water two mL saturated sodium chloride and fivemL cleanup solution (as given in Section 22) were addedshaken well and allowed to separate the two layers Organiclayer was collected and evaporated to dryness the residuewas dissolved in 10mL of the HPLC grade n-hexane tertiarybutyl methyl ether (4 1) mixture and analyzed using HPLCin UV detector
27 Chromatographic Conditions The quantificationof residues was done using High Performance LiquidChromatography (HPLCmdashHitachi Model L 6200) equippedwith normal phase column of Si-10 (Micropak) of 30 cmtimes 4mm dimension HPLC grade n-hexane and tertiarybutyl methyl ether 65 35 were used as mobile phase witha flow rate of 05mLminminus1 [22] Injection was done with arheodyne loop injector with a volume of 20 120583L and detectedin L 4200UV detector at a wavelength of 256 nm Theamount of diafenthiuron in the sample was calculatedaccording to the equation based on the ratio of the peakareas of the standard and sample as follows
Residues =119867119904
119867stdtimes119882std119882119904
times119881119904
119860 sj (1)
where 119867119904
is the peak height of the sample 119867std is the peakheight of the standard 119882std is the weight of the standardinjected in ng119882
119904
is the weight of the sample in g 119881119904
is thevolume of the sample (final extract) in mL and 119860 sj is theAliquot of the sample injected in 120583L
28 Method Validation and Recovery Studies Theparametersaccuracy precision linearity and limits of detection (LOD)and quantification (LOQ) were considered for method vali-dation For linearity test different known concentrations ofdiafenthiuron (025 05 10 and 15 120583gmLminus1) were preparedin distilled acetone n-hexane (05 95) vv by diluting thestock solution Peak areas of each standard solution weremeasured after injecting in HPLC and a calibration curveplotted with concentration of standards versus area of therespective peaks obtained The accuracy of the methodwas determined by recovery tests using fresh cardamomcapsule and soil sample (25 g) taken from organically grownplantation To work out the recovery percent of the ana-lytical methodology different known concentrations (010025 050 and 10 120583g gminus1) of diafenthiuron were made byadding required quantity from 10 120583g gminus1 standard solution incardamom capsule Each concentration was taken in threereplications Samples were equilibrated for 1 h prior to extrac-tion and subsequently taken through the extraction andcleanup procedures described above The limit of detection(LOD 120583gmLminus1) was determined as the lowest concentrationgiving a response of three times the baseline noise definedfrom the analysis of control (untreated) sample The limit ofquantification (LOQ 120583gmLminus1) was determined as the lowestconcentration of diafenthiuron giving a response of 10 timesthe baseline noise [23]
3 Results and Discussion
31 Method Validation
311 Specificity Diafenthiuron was detected at 661min(retention time) (Figure 2) through the above said proce-dures Specificity was confirmed by injecting cardamomextract from cardamom not treated with diafenthiuron (con-trol) and found nomatrix peaks interferingwith the retentiontime of diafenthiuron
312 Linearity Linearity test was made by plotting a stan-dard graphcalibration curve with different standard concen-trations (025 05 10 and 15120583gmLminus1) versus the respectivearea of the peaks obtained The linear regression equationobtained was 119910 = 33288119909 + 4203 with 1198772 09887
313 Detection and Quantification Limits The limit of quan-tification was determined to be 005 120583gmLminus1 The limitof quantification of the analytical method in cardamomcapsules was 005120583g gminus1 considering 25 g weight samples forextraction and 5mL of sample extract The limit of detectionwas determined to be 001 120583gmLminus1 at a level of approximatelythree times the background noise of control injection aroundthe retention time of the peak of interest The minimumdetection limit (sensitivity) of the instrument was 025 120583g gminus1
314 Precision Repeatability and Recovery Percentage Themean recovery percentage was found to be 607 625 592and 593 in green capsules and 585 593 633 and 617in cured capsules respectively for 010 025 050 and100 120583g gminus1 in fortified levels The standard deviations of
4 Chromatography Research International
(min)
0605040302010
SP
500
8001011
661
(a) 025120583gmLminus1 of diafenthiuron standard
(min)
0605040302010
SP
525
800
661
(b) 05120583gmLminus1 of diafenthiuron standard
(min)
0605040302010
SP
090
800
660
(c) 10 120583gmLminus1 of diafenthiuron standard
(min)
0605040302010
SP
200
800
661
(d) 15120583gmLminus1 of diafenthiuron standard
Figure 2 Standard chromatogram of diafenthiuron in HPLC
recovery percentages for both green and cured capsulesare well below 3 and thus the repeatability of the methodis quite good The mean recovery was 6043 and 6070 forgreen and cured capsules respectively The mean percentrecovery of 606 was obtained in the present study on residueanalysis of diafenthiuron which is much lower than thatof the expected recovery of more than 80 percent whichis normally used for validation of residue protocols It ispresumed that the low recovery is due to the conversionof diafenthiuron into its metabolites namely N-[26-bis(1-methylethyl)-4-phenoxyphenyl]-N1015840-(11-dimethylethyl)ureaand N-[26-bis(1-methylethyl)-4-phenoxyphenyl]-N1015840-(11-dimethylethyl)carbodiimide [24] for which standards arenot available Thus the residue data obtained in the presentstudy is only for the parent compound and hence weightagewas given by multiplying the residues obtained with therecovery factor 165 to get the actual quantum of residue
32 Harvest Time Residues in Cardamom Capsules Theresidues of diafenthiuron in harvested capsules of cardamomboth green and cured were below detectable limit at the timeof first harvest after third spray Residues of diafenthiuronin the soil samples on 14 and 17 days after application ofdiafenthiuron on cardamom that is at the time of harvestwere found below detectable limit (BDL)
33 Residues in Green Capsules of Cardamom Half Lifeand Waiting Period The initial deposit on green capsulesin diafenthiuron 400 g ai haminus1 was 382 and 410 120583g gminus1in first and second field trials respectively The depositwas as high as 661 to 732 120583g gminus1 at the higher dose ofdiafenthiuron (800 g ai haminus1) (Tables 1 and 2) The residuesdissipated to below detectable level (BDL) at 15 DAT in boththe concentrations evaluated in two seasons The extent ofreduction in diafenthiuron residues at one DAT was 1439to 2068 percent in diafenthiuron 400 g ai haminus1 The half lifevalues varied from 195 to 282 days for diafenthiuron 400 g ai haminus1 and 342 to 361 days for 800 g ai haminus1 The
maximum residue level (MRL) value for diafenthiuron oncardamom is not available Maximum Residue Limits (MRL)for diafenthiuron was fixed by Australian Pesticides andVeterinary Management Authority on other commoditiesnamely cotton seed (02mg gminus1) peanut (01mg gminus1) and eggmeat milk and poultry (002mg gminus1) [25] Japanese FoodChemical Research Foundation has suggested an MRL valueof 03 120583g gminus1 for cabbage whereas 20120583g gminus1 for tea [25] Sincethe suggested MRL is of very wide range from 03 120583g gminus1 to20120583g gminus1 the tentativeMRLvalue of 05120583g gminus1 for bell pepperused by Syngenta India Ltd was used for arriving waitingperiods in cardamom in the present study The waitingperiod worked out was 550 to 669 days for diafenthiuron 400 g ai haminus1 and 1133 to 1140 days at 800 g ai haminus1
34 Residues in Cured Capsules of Cardamom Half Lifeand Waiting Period The extent of dissipation of residues atone DAT was 2233 to 2419 and 1907 to 2107 percent indiafenthiuron 400 g ai haminus1 and 800 g ai haminus1 respectivelyThe percent dissipation was more than 95 percent in diafen-thiuron 400 g ai haminus1 at 10 DAT and the residues dissipatedto BDL in 15DATThe half life was 178 days for diafenthiuron 400 g ai haminus1 in both the trials and 159 to 302 fordiafenthiuron 800 g ai haminus1 The waiting period workedout was 539 to 701 days for diafenthiuron 400 g ai haminus1The correlation coefficients (119903) of the calibration curvesderived for dissipation of diafenthiuron in cured capsules areabove 09 which shows best fit (Tables 1 and 2)
35 Residues of Diafenthiuron Estimated in Moisture FreeBasis The initial deposit of diafenthiuron residues workedout on moisture free basis was 1384 and 1483 120583g gminus1 indiafenthiuron 400 g ai haminus1 2399 and 2571 120583g gminus1 indiafenthiuron 800 g ai haminus1 in the first and second fieldtrials respectively The residues detected in cured capsuleswere slightly high when compared to green capsules But lowlevel of quinalphos residues was reported earlier in curedcapsules than green capsules [26] Though there will be loss
Chromatography Research International 5
Table1Diss
ipationof
diafenthiuroninoncapsules
ofcardam
ommdashEx
perim
entIB
odim
ettu
DAT
Green
capsules
Curedcapsules
Moistu
refre
ebasis
Diafenthiuron
400g
aihaminus1
Diafenthiuron
800g
aihaminus1
Diafenthiuron
400g
aiaminus1
Diafenthiuron
800g
aihaminus1
Diafenthiuron
400g
aihaminus1
Diafenthiuron
800g
aihaminus1
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
0382
mdash661
mdash496
mdash818
mdash1384
mdash2399
mdash1
303
2068
503
2392
376
2419
662
1907
1095
2086
1789
2543
318
45183
393
4053
220
5565
516
3685
647
5325
1401
4160
7019
9503
191
7110
069
8609
321
6075
068
9509
690
7125
10BD
L10000
089
8651
008
9839
202
7531
BDL
10000
325
8644
15BD
Lmdash
BDL
10000
BDL
10000
013
9841
BDL
mdashBD
Lmdash
21BD
Lmdash
BDL
mdashBD
Lmdash
BDL
mdashBD
Lmdash
BDL
mdashHalflife
(Days)
2815
360
617
7815
915
803636
Waitin
gperio
d(D
ays)
6693
11401
5390
10930
7134
1437
3
119903value
0932
0995
09747
0982
0983
0995
Regressio
nequatio
n
119884=
1948minus
0336119909
119884=
1888minus
0192119909
119884=
1801minus
0390119909
119884=
2388minus
0246119909
119884=
2831minus
0439119909
119884=3163minus
0241119909
BDLbelowdetectablelim
it
6 Chromatography Research International
Table2Dissipationof
diafenthiuroninoncapsules
ofcardam
ommdashEx
perim
entIIDevarshola
DAT
Green
capsules
Curedcapsules
Moistu
refre
ebasis
Diafenthiuron
400g
aihaminus1Diafenthiuron
800g
aihaminus1Diafenthiuron
400g
aihaminus1Diafenthiuron
800g
aihaminus1Diafenthiuron
400g
aihaminus1Diafenthiuron
800g
aihaminus1
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
0410
mdash732
mdash533
mdash840
mdash1483
mdash2571
mdash1
351
1439
581
2063
414
2233
663
2107
1198
1918
2070
1948
3203
5049
423
4221
312
4146
561
3321
721
5139
1483
4231
7086
7902
193
7363
113
7880
313
6274
323
7823
699
7281
10009
9780
092
8743
021
9606
124
8524
033
9788
327
8728
15BD
Lmdash
BDL
10000
BDL
10000
022
9726
BDL
10000
BDL
10000
21BD
Lmdash
BDL
mdashBD
Lmdash
BDL
mdashBD
Lmdash
BDL
mdashHalflife
(days)
1949
3416
1778
3015
2815
344
1
Waitin
gperio
d(days)
5500
1133
970
0611387
9168
17750
119903value
0958
0999
0972
0977
0954
0997
Regressio
nequatio
n
119884=
1657minus
0356119909
119884=
2001minus
0203119909
119884=
1843minus
0306119909
119884=
2318minus
0230119909
119884=
2917minus
0351119909
119884=3266minus
0201119909
BDLbelowdetectablelim
it
Chromatography Research International 7
0
1
2
3
4
0 1 3 7 10
Log
resid
ues (
ppm
)
Period (days)
Linear (green capsules)Linear (cured capsules)Linear (moisture free basis)
Figure 3Dynamics of diafenthiuron (008) residues in cardamomcapsulesmdashExperiment I
0
1
2
3
4
0 1 3 7 10 15
Log
resid
ues (
ppm
)
Period (days)
Linear (green capsules)Linear (cured capsules)Linear (moisture free basis)
Figure 4 Dynamics of diafenthiuron (008) residues in car-damom capsulesmdashExperiment II
of residues in curing process (steaming and garbling) thereduction in weight should also be taken into account Themoisture content in green cardamom is about 70 percentSo when the capsules are driedcured the residues presentin 25 g of green cardamom sample will get concentrated inabout 7 g of cured capsules The dissipation of diafenthiuronis slower than the moisture loss during curing Thus thehigher residues of diafenthiuron in cured capsules than greencapsules obtained in the present study might be due to themoisture loss and high reduction in weight during curing
The dissipation pattern of diafenthiuron in cardamomgreen and cured samples is shown in Figures 3 and 4 Thedissipation rate was much faster in the present study whichis in line with the reports of Keum et al [19] stating veryhigh rate of degradation in Chinese cabbage The waitingperiod (119905MRL) for diafenthiuron was arrived at 550ndash669days in green and 701ndash713 days in cured capsules at therecommended dose of 008 percent This is lower than thereports made for profenofos 005 percent on green (1176days) and cured capsules (1082 days) [27]Thewaiting periodof lambda cyhalothrin (80 ppm) in cardamom was reportedas 88 to 109 days [28]The waiting period was reported to beseven days in green capsules of cardamom for diafenthiuronsprayed at 600 g ai haminus1 [22]
As mentioned earlier diafenthiuron is not approvedby Central Insecticide Board and Registration Committee
(CIBampRC) for spray in brinjal in view of long waiting periodof 10 days but approved for use in cardamom and subjectedfor fixing of tolerance limits [21] Picking of cardamomcapsules is carried out at an interval of 20ndash30 days As harvestbeing the focal point for enforcement of residue tolerancesthe suggested waiting period of seven days is safe enough tocontain the cardamom pests with diafenthiuron without theproblem of pesticide residues in harvestable produce
In conclusion it is clear that diafenthiuron dissipated toa level below detectable by seven days after spraying Usuallycardamomcapsules are harvested at an interval of 20ndash30 daysSo spraying of diafenthiuron does not possess any risk ofresidues in the harvestable produce if sprayed at least sevendays before harvesting
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
References
[1] H P Streibert J Drabek and A Rindisbacher ldquoDiafenthiurona new type of acaricideinsecticide for the control of the suckingpest complex in cotton and other cropsrdquo in Proceedings ofBrighton Crop Protection Conference Pests and Diseases BCPCFarnham pp 25ndash32 Syrrey UK 1988
[2] I Ishaaya S Kontsedalov D Mazirov and A R HorowitzldquoBiorational agents in IPM and IRM programs for controllingagricultural pestsrdquo Universiteit Gent vol 66 pp 363ndash374 2001
[3] C Saradha and RMNachiappan ldquoEvaluation of diafenthiuron50WP (Polo) against whitefly Bemisia tabaci Genn (Aleyro-didae Homoptera) on Brinjal (Solanum mlongena)rdquo Pestologyvol 27 pp 12ndash14 2003
[4] J J Patel B H Patel P D Bhatt and A B Manghodia ldquoBio-efficacy of diafenthiuron 50 WP against sucking pests of bri-njal (Solanum melangena L)rdquo in Biodiversity and Insect PestManagement S Ignacimuthu and S Jayaraj Eds pp 57ndash58Narosa Publishing House New Delhi India 2006
[5] M A Javed and G A Matthews ldquoBioresidual and integratedpestmanagement status of a biorational agent and a novel insec-ticide against whitefly and its key parasitoidsrdquo InternationalJournal of Pest Management vol 48 no 1 pp 13ndash17 2002
[6] J R Scarpellani ldquoEffect of thiamethoxam and diafenthiuron tonymphs of whitefly Bemisia argentifolli on beansrdquo in Proceed-ings of the 21th International Conference of Entomology p 711Iguassu Falls Brazil August 2000
[7] A Noor Field evaluation of newer insecticides against suckingpests infesting in chillies in Western Rajasthan [PhD thesis]Department of Entomology Agricultural Research StationRAU campus Mandor Jodhpur 2001
[8] M H Tatagar H D Mohankumar R K Mesta and MShivaprasad ldquoBioefficacy of new molecules Pegasus 50 WP tochilli thrips Scirtothrips dorsalis (Hood) and mites Polyphago-tarsonemus latus (Banks)rdquo Pestology vol 36 no 2 pp 19ndash212012
[9] UPASI Seventy Nine Annual Report Edited by N Muraleedha-ran and R Rajkumar UPASI Tea Research Found 2005
[10] R Sudhakaran P Rajakumari and A Mohandhas ldquoEvaluationof newer insecticides Match 5 EC and Polo 50 SC on the controlof insect pests on cottonrdquo Pestology vol 19 pp 14ndash18 1995
8 Chromatography Research International
[11] K R Kranthi S Kranthi et al ldquoIRM-Revolutionising cottonpestmanagement in IndiardquoResistant PestManagement Newslet-ter vol 14 pp 33ndash36 2004
[12] I Ishaaya Z Mendelson and A R Horowitz ldquoToxicity andgrowth-suppression exerted by diafenthiuron in the sweet-potatowhiteflyBemisia tabacirdquoPhytoparasitica vol 21 pp 199ndash204 1993
[13] S Lingappa K Basavanagoud K A Kulkarni S P Roopaand D N Kambrekar ldquoThreat to vegetable production by dia-mondback moth and its management strategiesrdquo in DiseaseManagement in Fruits and Vegetables pp 357ndash396 SpringerAmsterdam The Netherlands 2004
[14] J Stanley S Chandrasekaran G Preetha and S KuttalamldquoToxicity of diafenthiuron to honey bees in laboratory semi-field and field conditionsrdquo PestManagement Science vol 66 no5 pp 505ndash510 2010
[15] J Drabek M Boger J Ehrenfreund et al ldquoNew thioureasas insecticidesrdquo in Recent Advances in the Chemistry of InsectControl II C Crobie Ed vol 79 of Special Publication pp 170ndash183 Royal Society of Chemistry Cambridge UK 1992
[16] H A Kadir and C O Knowles ldquoToxicological studies of thethiourea diafenthiuron in diamondback moths and two spottedspider mites and bulb mitesrdquo Journal of Economic Entomologyvol 84 pp 780ndash784 1991
[17] IUPACDetection and Significance of ActiveMetabolites of Agro-chemicals and Related Xenobiotics in Animals vol 67 of Editedby RM Hollingworth N Kurihara J Miyamoto S Otto andGD Paulson International Union of Pure and Applied Chem-istry 1995
[18] H Kayser and P Eilinger ldquoMetabolism of diafenthiuron bymicrosomal oxidation procide activation and inactivation asmechanisms contributing to selectivityrdquo Pest Management Sci-ence vol 57 pp 975ndash980 2001
[19] Y-S Keum J-H Kim Y-W Kim K Kim and Q X Li ldquoPhoto-degradation of diafenthiuron in waterrdquo Pest Management Sci-ence vol 58 no 5 pp 496ndash502 2002
[20] Y S Keum K H Liu J S Seo et al ldquoDissipation of foliarresidues of diafenthiuron and its metabolitesrdquo Bulletin of Envi-ronmental Contamination and Toxicology vol 68 no 6 pp845ndash851 2002
[21] CIBampRC ldquoCentral Insecticide Board andRegistrationCommit-teerdquo 2006 httpwwwcibrcnicin267rcdoc
[22] D Rajabaskar and A Regupathy ldquoPersistence of diafenthiuronin cardamomrdquo Pesticide Research Journal vol 20 pp 247ndash2492008
[23] S Navickiene A Aquino and D S S Bezerra ldquoA matrix solid-phase dispersion method for the extraction of seven pesticidesfrom mango and papayardquo Journal of Chromatographic Sciencevol 48 no 9 pp 750ndash754 2010
[24] APVMA ldquoThe standard MRL in food and animal feed stuffMay 2007 Maximum residue levels of Agricultural and Veteri-nary chemicals and associated substances in food commodi-tiesrdquo 2007 httpwwwapvmagovauresidues
[25] Table of MRLs for Agricultural Chemicals ldquoThe Japan FoodChemical Research Foundationrdquo 2010 httpwwwffcrorjp
[26] S Valarmathi and A Regupathy ldquoEvaluation of two ecofriendlyformulations of quinalphos aqua flow (AF) and colloidal sus-pension (CS) on cardamomresiduesrdquo in 14th International PlantProtection Congress (IPPC rsquo99) Jerusalem Israel July 1999
[27] D Rajabaskar Studies on the evaluation of IPMmodules againstConogethes punctiferalis Guenee and Sciothrips cardamomi
Ramk on cardamom [PhD thesis] Tamil Nadu AgriculturalUniversity Coimbatore India 2003
[28] A Regupathy R S S Kumar D Rajabaskar and K ChozhanldquoDetermination of residues of profenophos in cardamomrdquo inProceedings of National Seminar on Resource Management inPlant Protection during Twenty First Century Hyderabad India2002
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
4 Chromatography Research International
(min)
0605040302010
SP
500
8001011
661
(a) 025120583gmLminus1 of diafenthiuron standard
(min)
0605040302010
SP
525
800
661
(b) 05120583gmLminus1 of diafenthiuron standard
(min)
0605040302010
SP
090
800
660
(c) 10 120583gmLminus1 of diafenthiuron standard
(min)
0605040302010
SP
200
800
661
(d) 15120583gmLminus1 of diafenthiuron standard
Figure 2 Standard chromatogram of diafenthiuron in HPLC
recovery percentages for both green and cured capsulesare well below 3 and thus the repeatability of the methodis quite good The mean recovery was 6043 and 6070 forgreen and cured capsules respectively The mean percentrecovery of 606 was obtained in the present study on residueanalysis of diafenthiuron which is much lower than thatof the expected recovery of more than 80 percent whichis normally used for validation of residue protocols It ispresumed that the low recovery is due to the conversionof diafenthiuron into its metabolites namely N-[26-bis(1-methylethyl)-4-phenoxyphenyl]-N1015840-(11-dimethylethyl)ureaand N-[26-bis(1-methylethyl)-4-phenoxyphenyl]-N1015840-(11-dimethylethyl)carbodiimide [24] for which standards arenot available Thus the residue data obtained in the presentstudy is only for the parent compound and hence weightagewas given by multiplying the residues obtained with therecovery factor 165 to get the actual quantum of residue
32 Harvest Time Residues in Cardamom Capsules Theresidues of diafenthiuron in harvested capsules of cardamomboth green and cured were below detectable limit at the timeof first harvest after third spray Residues of diafenthiuronin the soil samples on 14 and 17 days after application ofdiafenthiuron on cardamom that is at the time of harvestwere found below detectable limit (BDL)
33 Residues in Green Capsules of Cardamom Half Lifeand Waiting Period The initial deposit on green capsulesin diafenthiuron 400 g ai haminus1 was 382 and 410 120583g gminus1in first and second field trials respectively The depositwas as high as 661 to 732 120583g gminus1 at the higher dose ofdiafenthiuron (800 g ai haminus1) (Tables 1 and 2) The residuesdissipated to below detectable level (BDL) at 15 DAT in boththe concentrations evaluated in two seasons The extent ofreduction in diafenthiuron residues at one DAT was 1439to 2068 percent in diafenthiuron 400 g ai haminus1 The half lifevalues varied from 195 to 282 days for diafenthiuron 400 g ai haminus1 and 342 to 361 days for 800 g ai haminus1 The
maximum residue level (MRL) value for diafenthiuron oncardamom is not available Maximum Residue Limits (MRL)for diafenthiuron was fixed by Australian Pesticides andVeterinary Management Authority on other commoditiesnamely cotton seed (02mg gminus1) peanut (01mg gminus1) and eggmeat milk and poultry (002mg gminus1) [25] Japanese FoodChemical Research Foundation has suggested an MRL valueof 03 120583g gminus1 for cabbage whereas 20120583g gminus1 for tea [25] Sincethe suggested MRL is of very wide range from 03 120583g gminus1 to20120583g gminus1 the tentativeMRLvalue of 05120583g gminus1 for bell pepperused by Syngenta India Ltd was used for arriving waitingperiods in cardamom in the present study The waitingperiod worked out was 550 to 669 days for diafenthiuron 400 g ai haminus1 and 1133 to 1140 days at 800 g ai haminus1
34 Residues in Cured Capsules of Cardamom Half Lifeand Waiting Period The extent of dissipation of residues atone DAT was 2233 to 2419 and 1907 to 2107 percent indiafenthiuron 400 g ai haminus1 and 800 g ai haminus1 respectivelyThe percent dissipation was more than 95 percent in diafen-thiuron 400 g ai haminus1 at 10 DAT and the residues dissipatedto BDL in 15DATThe half life was 178 days for diafenthiuron 400 g ai haminus1 in both the trials and 159 to 302 fordiafenthiuron 800 g ai haminus1 The waiting period workedout was 539 to 701 days for diafenthiuron 400 g ai haminus1The correlation coefficients (119903) of the calibration curvesderived for dissipation of diafenthiuron in cured capsules areabove 09 which shows best fit (Tables 1 and 2)
35 Residues of Diafenthiuron Estimated in Moisture FreeBasis The initial deposit of diafenthiuron residues workedout on moisture free basis was 1384 and 1483 120583g gminus1 indiafenthiuron 400 g ai haminus1 2399 and 2571 120583g gminus1 indiafenthiuron 800 g ai haminus1 in the first and second fieldtrials respectively The residues detected in cured capsuleswere slightly high when compared to green capsules But lowlevel of quinalphos residues was reported earlier in curedcapsules than green capsules [26] Though there will be loss
Chromatography Research International 5
Table1Diss
ipationof
diafenthiuroninoncapsules
ofcardam
ommdashEx
perim
entIB
odim
ettu
DAT
Green
capsules
Curedcapsules
Moistu
refre
ebasis
Diafenthiuron
400g
aihaminus1
Diafenthiuron
800g
aihaminus1
Diafenthiuron
400g
aiaminus1
Diafenthiuron
800g
aihaminus1
Diafenthiuron
400g
aihaminus1
Diafenthiuron
800g
aihaminus1
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
0382
mdash661
mdash496
mdash818
mdash1384
mdash2399
mdash1
303
2068
503
2392
376
2419
662
1907
1095
2086
1789
2543
318
45183
393
4053
220
5565
516
3685
647
5325
1401
4160
7019
9503
191
7110
069
8609
321
6075
068
9509
690
7125
10BD
L10000
089
8651
008
9839
202
7531
BDL
10000
325
8644
15BD
Lmdash
BDL
10000
BDL
10000
013
9841
BDL
mdashBD
Lmdash
21BD
Lmdash
BDL
mdashBD
Lmdash
BDL
mdashBD
Lmdash
BDL
mdashHalflife
(Days)
2815
360
617
7815
915
803636
Waitin
gperio
d(D
ays)
6693
11401
5390
10930
7134
1437
3
119903value
0932
0995
09747
0982
0983
0995
Regressio
nequatio
n
119884=
1948minus
0336119909
119884=
1888minus
0192119909
119884=
1801minus
0390119909
119884=
2388minus
0246119909
119884=
2831minus
0439119909
119884=3163minus
0241119909
BDLbelowdetectablelim
it
6 Chromatography Research International
Table2Dissipationof
diafenthiuroninoncapsules
ofcardam
ommdashEx
perim
entIIDevarshola
DAT
Green
capsules
Curedcapsules
Moistu
refre
ebasis
Diafenthiuron
400g
aihaminus1Diafenthiuron
800g
aihaminus1Diafenthiuron
400g
aihaminus1Diafenthiuron
800g
aihaminus1Diafenthiuron
400g
aihaminus1Diafenthiuron
800g
aihaminus1
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
0410
mdash732
mdash533
mdash840
mdash1483
mdash2571
mdash1
351
1439
581
2063
414
2233
663
2107
1198
1918
2070
1948
3203
5049
423
4221
312
4146
561
3321
721
5139
1483
4231
7086
7902
193
7363
113
7880
313
6274
323
7823
699
7281
10009
9780
092
8743
021
9606
124
8524
033
9788
327
8728
15BD
Lmdash
BDL
10000
BDL
10000
022
9726
BDL
10000
BDL
10000
21BD
Lmdash
BDL
mdashBD
Lmdash
BDL
mdashBD
Lmdash
BDL
mdashHalflife
(days)
1949
3416
1778
3015
2815
344
1
Waitin
gperio
d(days)
5500
1133
970
0611387
9168
17750
119903value
0958
0999
0972
0977
0954
0997
Regressio
nequatio
n
119884=
1657minus
0356119909
119884=
2001minus
0203119909
119884=
1843minus
0306119909
119884=
2318minus
0230119909
119884=
2917minus
0351119909
119884=3266minus
0201119909
BDLbelowdetectablelim
it
Chromatography Research International 7
0
1
2
3
4
0 1 3 7 10
Log
resid
ues (
ppm
)
Period (days)
Linear (green capsules)Linear (cured capsules)Linear (moisture free basis)
Figure 3Dynamics of diafenthiuron (008) residues in cardamomcapsulesmdashExperiment I
0
1
2
3
4
0 1 3 7 10 15
Log
resid
ues (
ppm
)
Period (days)
Linear (green capsules)Linear (cured capsules)Linear (moisture free basis)
Figure 4 Dynamics of diafenthiuron (008) residues in car-damom capsulesmdashExperiment II
of residues in curing process (steaming and garbling) thereduction in weight should also be taken into account Themoisture content in green cardamom is about 70 percentSo when the capsules are driedcured the residues presentin 25 g of green cardamom sample will get concentrated inabout 7 g of cured capsules The dissipation of diafenthiuronis slower than the moisture loss during curing Thus thehigher residues of diafenthiuron in cured capsules than greencapsules obtained in the present study might be due to themoisture loss and high reduction in weight during curing
The dissipation pattern of diafenthiuron in cardamomgreen and cured samples is shown in Figures 3 and 4 Thedissipation rate was much faster in the present study whichis in line with the reports of Keum et al [19] stating veryhigh rate of degradation in Chinese cabbage The waitingperiod (119905MRL) for diafenthiuron was arrived at 550ndash669days in green and 701ndash713 days in cured capsules at therecommended dose of 008 percent This is lower than thereports made for profenofos 005 percent on green (1176days) and cured capsules (1082 days) [27]Thewaiting periodof lambda cyhalothrin (80 ppm) in cardamom was reportedas 88 to 109 days [28]The waiting period was reported to beseven days in green capsules of cardamom for diafenthiuronsprayed at 600 g ai haminus1 [22]
As mentioned earlier diafenthiuron is not approvedby Central Insecticide Board and Registration Committee
(CIBampRC) for spray in brinjal in view of long waiting periodof 10 days but approved for use in cardamom and subjectedfor fixing of tolerance limits [21] Picking of cardamomcapsules is carried out at an interval of 20ndash30 days As harvestbeing the focal point for enforcement of residue tolerancesthe suggested waiting period of seven days is safe enough tocontain the cardamom pests with diafenthiuron without theproblem of pesticide residues in harvestable produce
In conclusion it is clear that diafenthiuron dissipated toa level below detectable by seven days after spraying Usuallycardamomcapsules are harvested at an interval of 20ndash30 daysSo spraying of diafenthiuron does not possess any risk ofresidues in the harvestable produce if sprayed at least sevendays before harvesting
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
References
[1] H P Streibert J Drabek and A Rindisbacher ldquoDiafenthiurona new type of acaricideinsecticide for the control of the suckingpest complex in cotton and other cropsrdquo in Proceedings ofBrighton Crop Protection Conference Pests and Diseases BCPCFarnham pp 25ndash32 Syrrey UK 1988
[2] I Ishaaya S Kontsedalov D Mazirov and A R HorowitzldquoBiorational agents in IPM and IRM programs for controllingagricultural pestsrdquo Universiteit Gent vol 66 pp 363ndash374 2001
[3] C Saradha and RMNachiappan ldquoEvaluation of diafenthiuron50WP (Polo) against whitefly Bemisia tabaci Genn (Aleyro-didae Homoptera) on Brinjal (Solanum mlongena)rdquo Pestologyvol 27 pp 12ndash14 2003
[4] J J Patel B H Patel P D Bhatt and A B Manghodia ldquoBio-efficacy of diafenthiuron 50 WP against sucking pests of bri-njal (Solanum melangena L)rdquo in Biodiversity and Insect PestManagement S Ignacimuthu and S Jayaraj Eds pp 57ndash58Narosa Publishing House New Delhi India 2006
[5] M A Javed and G A Matthews ldquoBioresidual and integratedpestmanagement status of a biorational agent and a novel insec-ticide against whitefly and its key parasitoidsrdquo InternationalJournal of Pest Management vol 48 no 1 pp 13ndash17 2002
[6] J R Scarpellani ldquoEffect of thiamethoxam and diafenthiuron tonymphs of whitefly Bemisia argentifolli on beansrdquo in Proceed-ings of the 21th International Conference of Entomology p 711Iguassu Falls Brazil August 2000
[7] A Noor Field evaluation of newer insecticides against suckingpests infesting in chillies in Western Rajasthan [PhD thesis]Department of Entomology Agricultural Research StationRAU campus Mandor Jodhpur 2001
[8] M H Tatagar H D Mohankumar R K Mesta and MShivaprasad ldquoBioefficacy of new molecules Pegasus 50 WP tochilli thrips Scirtothrips dorsalis (Hood) and mites Polyphago-tarsonemus latus (Banks)rdquo Pestology vol 36 no 2 pp 19ndash212012
[9] UPASI Seventy Nine Annual Report Edited by N Muraleedha-ran and R Rajkumar UPASI Tea Research Found 2005
[10] R Sudhakaran P Rajakumari and A Mohandhas ldquoEvaluationof newer insecticides Match 5 EC and Polo 50 SC on the controlof insect pests on cottonrdquo Pestology vol 19 pp 14ndash18 1995
8 Chromatography Research International
[11] K R Kranthi S Kranthi et al ldquoIRM-Revolutionising cottonpestmanagement in IndiardquoResistant PestManagement Newslet-ter vol 14 pp 33ndash36 2004
[12] I Ishaaya Z Mendelson and A R Horowitz ldquoToxicity andgrowth-suppression exerted by diafenthiuron in the sweet-potatowhiteflyBemisia tabacirdquoPhytoparasitica vol 21 pp 199ndash204 1993
[13] S Lingappa K Basavanagoud K A Kulkarni S P Roopaand D N Kambrekar ldquoThreat to vegetable production by dia-mondback moth and its management strategiesrdquo in DiseaseManagement in Fruits and Vegetables pp 357ndash396 SpringerAmsterdam The Netherlands 2004
[14] J Stanley S Chandrasekaran G Preetha and S KuttalamldquoToxicity of diafenthiuron to honey bees in laboratory semi-field and field conditionsrdquo PestManagement Science vol 66 no5 pp 505ndash510 2010
[15] J Drabek M Boger J Ehrenfreund et al ldquoNew thioureasas insecticidesrdquo in Recent Advances in the Chemistry of InsectControl II C Crobie Ed vol 79 of Special Publication pp 170ndash183 Royal Society of Chemistry Cambridge UK 1992
[16] H A Kadir and C O Knowles ldquoToxicological studies of thethiourea diafenthiuron in diamondback moths and two spottedspider mites and bulb mitesrdquo Journal of Economic Entomologyvol 84 pp 780ndash784 1991
[17] IUPACDetection and Significance of ActiveMetabolites of Agro-chemicals and Related Xenobiotics in Animals vol 67 of Editedby RM Hollingworth N Kurihara J Miyamoto S Otto andGD Paulson International Union of Pure and Applied Chem-istry 1995
[18] H Kayser and P Eilinger ldquoMetabolism of diafenthiuron bymicrosomal oxidation procide activation and inactivation asmechanisms contributing to selectivityrdquo Pest Management Sci-ence vol 57 pp 975ndash980 2001
[19] Y-S Keum J-H Kim Y-W Kim K Kim and Q X Li ldquoPhoto-degradation of diafenthiuron in waterrdquo Pest Management Sci-ence vol 58 no 5 pp 496ndash502 2002
[20] Y S Keum K H Liu J S Seo et al ldquoDissipation of foliarresidues of diafenthiuron and its metabolitesrdquo Bulletin of Envi-ronmental Contamination and Toxicology vol 68 no 6 pp845ndash851 2002
[21] CIBampRC ldquoCentral Insecticide Board andRegistrationCommit-teerdquo 2006 httpwwwcibrcnicin267rcdoc
[22] D Rajabaskar and A Regupathy ldquoPersistence of diafenthiuronin cardamomrdquo Pesticide Research Journal vol 20 pp 247ndash2492008
[23] S Navickiene A Aquino and D S S Bezerra ldquoA matrix solid-phase dispersion method for the extraction of seven pesticidesfrom mango and papayardquo Journal of Chromatographic Sciencevol 48 no 9 pp 750ndash754 2010
[24] APVMA ldquoThe standard MRL in food and animal feed stuffMay 2007 Maximum residue levels of Agricultural and Veteri-nary chemicals and associated substances in food commodi-tiesrdquo 2007 httpwwwapvmagovauresidues
[25] Table of MRLs for Agricultural Chemicals ldquoThe Japan FoodChemical Research Foundationrdquo 2010 httpwwwffcrorjp
[26] S Valarmathi and A Regupathy ldquoEvaluation of two ecofriendlyformulations of quinalphos aqua flow (AF) and colloidal sus-pension (CS) on cardamomresiduesrdquo in 14th International PlantProtection Congress (IPPC rsquo99) Jerusalem Israel July 1999
[27] D Rajabaskar Studies on the evaluation of IPMmodules againstConogethes punctiferalis Guenee and Sciothrips cardamomi
Ramk on cardamom [PhD thesis] Tamil Nadu AgriculturalUniversity Coimbatore India 2003
[28] A Regupathy R S S Kumar D Rajabaskar and K ChozhanldquoDetermination of residues of profenophos in cardamomrdquo inProceedings of National Seminar on Resource Management inPlant Protection during Twenty First Century Hyderabad India2002
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
Chromatography Research International 5
Table1Diss
ipationof
diafenthiuroninoncapsules
ofcardam
ommdashEx
perim
entIB
odim
ettu
DAT
Green
capsules
Curedcapsules
Moistu
refre
ebasis
Diafenthiuron
400g
aihaminus1
Diafenthiuron
800g
aihaminus1
Diafenthiuron
400g
aiaminus1
Diafenthiuron
800g
aihaminus1
Diafenthiuron
400g
aihaminus1
Diafenthiuron
800g
aihaminus1
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
Resid
ues
(120583ggminus1
)Dissipation
(Percent)
0382
mdash661
mdash496
mdash818
mdash1384
mdash2399
mdash1
303
2068
503
2392
376
2419
662
1907
1095
2086
1789
2543
318
45183
393
4053
220
5565
516
3685
647
5325
1401
4160
7019
9503
191
7110
069
8609
321
6075
068
9509
690
7125
10BD
L10000
089
8651
008
9839
202
7531
BDL
10000
325
8644
15BD
Lmdash
BDL
10000
BDL
10000
013
9841
BDL
mdashBD
Lmdash
21BD
Lmdash
BDL
mdashBD
Lmdash
BDL
mdashBD
Lmdash
BDL
mdashHalflife
(Days)
2815
360
617
7815
915
803636
Waitin
gperio
d(D
ays)
6693
11401
5390
10930
7134
1437
3
119903value
0932
0995
09747
0982
0983
0995
Regressio
nequatio
n
119884=
1948minus
0336119909
119884=
1888minus
0192119909
119884=
1801minus
0390119909
119884=
2388minus
0246119909
119884=
2831minus
0439119909
119884=3163minus
0241119909
BDLbelowdetectablelim
it
6 Chromatography Research International
Table2Dissipationof
diafenthiuroninoncapsules
ofcardam
ommdashEx
perim
entIIDevarshola
DAT
Green
capsules
Curedcapsules
Moistu
refre
ebasis
Diafenthiuron
400g
aihaminus1Diafenthiuron
800g
aihaminus1Diafenthiuron
400g
aihaminus1Diafenthiuron
800g
aihaminus1Diafenthiuron
400g
aihaminus1Diafenthiuron
800g
aihaminus1
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
0410
mdash732
mdash533
mdash840
mdash1483
mdash2571
mdash1
351
1439
581
2063
414
2233
663
2107
1198
1918
2070
1948
3203
5049
423
4221
312
4146
561
3321
721
5139
1483
4231
7086
7902
193
7363
113
7880
313
6274
323
7823
699
7281
10009
9780
092
8743
021
9606
124
8524
033
9788
327
8728
15BD
Lmdash
BDL
10000
BDL
10000
022
9726
BDL
10000
BDL
10000
21BD
Lmdash
BDL
mdashBD
Lmdash
BDL
mdashBD
Lmdash
BDL
mdashHalflife
(days)
1949
3416
1778
3015
2815
344
1
Waitin
gperio
d(days)
5500
1133
970
0611387
9168
17750
119903value
0958
0999
0972
0977
0954
0997
Regressio
nequatio
n
119884=
1657minus
0356119909
119884=
2001minus
0203119909
119884=
1843minus
0306119909
119884=
2318minus
0230119909
119884=
2917minus
0351119909
119884=3266minus
0201119909
BDLbelowdetectablelim
it
Chromatography Research International 7
0
1
2
3
4
0 1 3 7 10
Log
resid
ues (
ppm
)
Period (days)
Linear (green capsules)Linear (cured capsules)Linear (moisture free basis)
Figure 3Dynamics of diafenthiuron (008) residues in cardamomcapsulesmdashExperiment I
0
1
2
3
4
0 1 3 7 10 15
Log
resid
ues (
ppm
)
Period (days)
Linear (green capsules)Linear (cured capsules)Linear (moisture free basis)
Figure 4 Dynamics of diafenthiuron (008) residues in car-damom capsulesmdashExperiment II
of residues in curing process (steaming and garbling) thereduction in weight should also be taken into account Themoisture content in green cardamom is about 70 percentSo when the capsules are driedcured the residues presentin 25 g of green cardamom sample will get concentrated inabout 7 g of cured capsules The dissipation of diafenthiuronis slower than the moisture loss during curing Thus thehigher residues of diafenthiuron in cured capsules than greencapsules obtained in the present study might be due to themoisture loss and high reduction in weight during curing
The dissipation pattern of diafenthiuron in cardamomgreen and cured samples is shown in Figures 3 and 4 Thedissipation rate was much faster in the present study whichis in line with the reports of Keum et al [19] stating veryhigh rate of degradation in Chinese cabbage The waitingperiod (119905MRL) for diafenthiuron was arrived at 550ndash669days in green and 701ndash713 days in cured capsules at therecommended dose of 008 percent This is lower than thereports made for profenofos 005 percent on green (1176days) and cured capsules (1082 days) [27]Thewaiting periodof lambda cyhalothrin (80 ppm) in cardamom was reportedas 88 to 109 days [28]The waiting period was reported to beseven days in green capsules of cardamom for diafenthiuronsprayed at 600 g ai haminus1 [22]
As mentioned earlier diafenthiuron is not approvedby Central Insecticide Board and Registration Committee
(CIBampRC) for spray in brinjal in view of long waiting periodof 10 days but approved for use in cardamom and subjectedfor fixing of tolerance limits [21] Picking of cardamomcapsules is carried out at an interval of 20ndash30 days As harvestbeing the focal point for enforcement of residue tolerancesthe suggested waiting period of seven days is safe enough tocontain the cardamom pests with diafenthiuron without theproblem of pesticide residues in harvestable produce
In conclusion it is clear that diafenthiuron dissipated toa level below detectable by seven days after spraying Usuallycardamomcapsules are harvested at an interval of 20ndash30 daysSo spraying of diafenthiuron does not possess any risk ofresidues in the harvestable produce if sprayed at least sevendays before harvesting
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
References
[1] H P Streibert J Drabek and A Rindisbacher ldquoDiafenthiurona new type of acaricideinsecticide for the control of the suckingpest complex in cotton and other cropsrdquo in Proceedings ofBrighton Crop Protection Conference Pests and Diseases BCPCFarnham pp 25ndash32 Syrrey UK 1988
[2] I Ishaaya S Kontsedalov D Mazirov and A R HorowitzldquoBiorational agents in IPM and IRM programs for controllingagricultural pestsrdquo Universiteit Gent vol 66 pp 363ndash374 2001
[3] C Saradha and RMNachiappan ldquoEvaluation of diafenthiuron50WP (Polo) against whitefly Bemisia tabaci Genn (Aleyro-didae Homoptera) on Brinjal (Solanum mlongena)rdquo Pestologyvol 27 pp 12ndash14 2003
[4] J J Patel B H Patel P D Bhatt and A B Manghodia ldquoBio-efficacy of diafenthiuron 50 WP against sucking pests of bri-njal (Solanum melangena L)rdquo in Biodiversity and Insect PestManagement S Ignacimuthu and S Jayaraj Eds pp 57ndash58Narosa Publishing House New Delhi India 2006
[5] M A Javed and G A Matthews ldquoBioresidual and integratedpestmanagement status of a biorational agent and a novel insec-ticide against whitefly and its key parasitoidsrdquo InternationalJournal of Pest Management vol 48 no 1 pp 13ndash17 2002
[6] J R Scarpellani ldquoEffect of thiamethoxam and diafenthiuron tonymphs of whitefly Bemisia argentifolli on beansrdquo in Proceed-ings of the 21th International Conference of Entomology p 711Iguassu Falls Brazil August 2000
[7] A Noor Field evaluation of newer insecticides against suckingpests infesting in chillies in Western Rajasthan [PhD thesis]Department of Entomology Agricultural Research StationRAU campus Mandor Jodhpur 2001
[8] M H Tatagar H D Mohankumar R K Mesta and MShivaprasad ldquoBioefficacy of new molecules Pegasus 50 WP tochilli thrips Scirtothrips dorsalis (Hood) and mites Polyphago-tarsonemus latus (Banks)rdquo Pestology vol 36 no 2 pp 19ndash212012
[9] UPASI Seventy Nine Annual Report Edited by N Muraleedha-ran and R Rajkumar UPASI Tea Research Found 2005
[10] R Sudhakaran P Rajakumari and A Mohandhas ldquoEvaluationof newer insecticides Match 5 EC and Polo 50 SC on the controlof insect pests on cottonrdquo Pestology vol 19 pp 14ndash18 1995
8 Chromatography Research International
[11] K R Kranthi S Kranthi et al ldquoIRM-Revolutionising cottonpestmanagement in IndiardquoResistant PestManagement Newslet-ter vol 14 pp 33ndash36 2004
[12] I Ishaaya Z Mendelson and A R Horowitz ldquoToxicity andgrowth-suppression exerted by diafenthiuron in the sweet-potatowhiteflyBemisia tabacirdquoPhytoparasitica vol 21 pp 199ndash204 1993
[13] S Lingappa K Basavanagoud K A Kulkarni S P Roopaand D N Kambrekar ldquoThreat to vegetable production by dia-mondback moth and its management strategiesrdquo in DiseaseManagement in Fruits and Vegetables pp 357ndash396 SpringerAmsterdam The Netherlands 2004
[14] J Stanley S Chandrasekaran G Preetha and S KuttalamldquoToxicity of diafenthiuron to honey bees in laboratory semi-field and field conditionsrdquo PestManagement Science vol 66 no5 pp 505ndash510 2010
[15] J Drabek M Boger J Ehrenfreund et al ldquoNew thioureasas insecticidesrdquo in Recent Advances in the Chemistry of InsectControl II C Crobie Ed vol 79 of Special Publication pp 170ndash183 Royal Society of Chemistry Cambridge UK 1992
[16] H A Kadir and C O Knowles ldquoToxicological studies of thethiourea diafenthiuron in diamondback moths and two spottedspider mites and bulb mitesrdquo Journal of Economic Entomologyvol 84 pp 780ndash784 1991
[17] IUPACDetection and Significance of ActiveMetabolites of Agro-chemicals and Related Xenobiotics in Animals vol 67 of Editedby RM Hollingworth N Kurihara J Miyamoto S Otto andGD Paulson International Union of Pure and Applied Chem-istry 1995
[18] H Kayser and P Eilinger ldquoMetabolism of diafenthiuron bymicrosomal oxidation procide activation and inactivation asmechanisms contributing to selectivityrdquo Pest Management Sci-ence vol 57 pp 975ndash980 2001
[19] Y-S Keum J-H Kim Y-W Kim K Kim and Q X Li ldquoPhoto-degradation of diafenthiuron in waterrdquo Pest Management Sci-ence vol 58 no 5 pp 496ndash502 2002
[20] Y S Keum K H Liu J S Seo et al ldquoDissipation of foliarresidues of diafenthiuron and its metabolitesrdquo Bulletin of Envi-ronmental Contamination and Toxicology vol 68 no 6 pp845ndash851 2002
[21] CIBampRC ldquoCentral Insecticide Board andRegistrationCommit-teerdquo 2006 httpwwwcibrcnicin267rcdoc
[22] D Rajabaskar and A Regupathy ldquoPersistence of diafenthiuronin cardamomrdquo Pesticide Research Journal vol 20 pp 247ndash2492008
[23] S Navickiene A Aquino and D S S Bezerra ldquoA matrix solid-phase dispersion method for the extraction of seven pesticidesfrom mango and papayardquo Journal of Chromatographic Sciencevol 48 no 9 pp 750ndash754 2010
[24] APVMA ldquoThe standard MRL in food and animal feed stuffMay 2007 Maximum residue levels of Agricultural and Veteri-nary chemicals and associated substances in food commodi-tiesrdquo 2007 httpwwwapvmagovauresidues
[25] Table of MRLs for Agricultural Chemicals ldquoThe Japan FoodChemical Research Foundationrdquo 2010 httpwwwffcrorjp
[26] S Valarmathi and A Regupathy ldquoEvaluation of two ecofriendlyformulations of quinalphos aqua flow (AF) and colloidal sus-pension (CS) on cardamomresiduesrdquo in 14th International PlantProtection Congress (IPPC rsquo99) Jerusalem Israel July 1999
[27] D Rajabaskar Studies on the evaluation of IPMmodules againstConogethes punctiferalis Guenee and Sciothrips cardamomi
Ramk on cardamom [PhD thesis] Tamil Nadu AgriculturalUniversity Coimbatore India 2003
[28] A Regupathy R S S Kumar D Rajabaskar and K ChozhanldquoDetermination of residues of profenophos in cardamomrdquo inProceedings of National Seminar on Resource Management inPlant Protection during Twenty First Century Hyderabad India2002
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
6 Chromatography Research International
Table2Dissipationof
diafenthiuroninoncapsules
ofcardam
ommdashEx
perim
entIIDevarshola
DAT
Green
capsules
Curedcapsules
Moistu
refre
ebasis
Diafenthiuron
400g
aihaminus1Diafenthiuron
800g
aihaminus1Diafenthiuron
400g
aihaminus1Diafenthiuron
800g
aihaminus1Diafenthiuron
400g
aihaminus1Diafenthiuron
800g
aihaminus1
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
Resid
ues
(120583ggminus1 )
Dissipation
()
0410
mdash732
mdash533
mdash840
mdash1483
mdash2571
mdash1
351
1439
581
2063
414
2233
663
2107
1198
1918
2070
1948
3203
5049
423
4221
312
4146
561
3321
721
5139
1483
4231
7086
7902
193
7363
113
7880
313
6274
323
7823
699
7281
10009
9780
092
8743
021
9606
124
8524
033
9788
327
8728
15BD
Lmdash
BDL
10000
BDL
10000
022
9726
BDL
10000
BDL
10000
21BD
Lmdash
BDL
mdashBD
Lmdash
BDL
mdashBD
Lmdash
BDL
mdashHalflife
(days)
1949
3416
1778
3015
2815
344
1
Waitin
gperio
d(days)
5500
1133
970
0611387
9168
17750
119903value
0958
0999
0972
0977
0954
0997
Regressio
nequatio
n
119884=
1657minus
0356119909
119884=
2001minus
0203119909
119884=
1843minus
0306119909
119884=
2318minus
0230119909
119884=
2917minus
0351119909
119884=3266minus
0201119909
BDLbelowdetectablelim
it
Chromatography Research International 7
0
1
2
3
4
0 1 3 7 10
Log
resid
ues (
ppm
)
Period (days)
Linear (green capsules)Linear (cured capsules)Linear (moisture free basis)
Figure 3Dynamics of diafenthiuron (008) residues in cardamomcapsulesmdashExperiment I
0
1
2
3
4
0 1 3 7 10 15
Log
resid
ues (
ppm
)
Period (days)
Linear (green capsules)Linear (cured capsules)Linear (moisture free basis)
Figure 4 Dynamics of diafenthiuron (008) residues in car-damom capsulesmdashExperiment II
of residues in curing process (steaming and garbling) thereduction in weight should also be taken into account Themoisture content in green cardamom is about 70 percentSo when the capsules are driedcured the residues presentin 25 g of green cardamom sample will get concentrated inabout 7 g of cured capsules The dissipation of diafenthiuronis slower than the moisture loss during curing Thus thehigher residues of diafenthiuron in cured capsules than greencapsules obtained in the present study might be due to themoisture loss and high reduction in weight during curing
The dissipation pattern of diafenthiuron in cardamomgreen and cured samples is shown in Figures 3 and 4 Thedissipation rate was much faster in the present study whichis in line with the reports of Keum et al [19] stating veryhigh rate of degradation in Chinese cabbage The waitingperiod (119905MRL) for diafenthiuron was arrived at 550ndash669days in green and 701ndash713 days in cured capsules at therecommended dose of 008 percent This is lower than thereports made for profenofos 005 percent on green (1176days) and cured capsules (1082 days) [27]Thewaiting periodof lambda cyhalothrin (80 ppm) in cardamom was reportedas 88 to 109 days [28]The waiting period was reported to beseven days in green capsules of cardamom for diafenthiuronsprayed at 600 g ai haminus1 [22]
As mentioned earlier diafenthiuron is not approvedby Central Insecticide Board and Registration Committee
(CIBampRC) for spray in brinjal in view of long waiting periodof 10 days but approved for use in cardamom and subjectedfor fixing of tolerance limits [21] Picking of cardamomcapsules is carried out at an interval of 20ndash30 days As harvestbeing the focal point for enforcement of residue tolerancesthe suggested waiting period of seven days is safe enough tocontain the cardamom pests with diafenthiuron without theproblem of pesticide residues in harvestable produce
In conclusion it is clear that diafenthiuron dissipated toa level below detectable by seven days after spraying Usuallycardamomcapsules are harvested at an interval of 20ndash30 daysSo spraying of diafenthiuron does not possess any risk ofresidues in the harvestable produce if sprayed at least sevendays before harvesting
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
References
[1] H P Streibert J Drabek and A Rindisbacher ldquoDiafenthiurona new type of acaricideinsecticide for the control of the suckingpest complex in cotton and other cropsrdquo in Proceedings ofBrighton Crop Protection Conference Pests and Diseases BCPCFarnham pp 25ndash32 Syrrey UK 1988
[2] I Ishaaya S Kontsedalov D Mazirov and A R HorowitzldquoBiorational agents in IPM and IRM programs for controllingagricultural pestsrdquo Universiteit Gent vol 66 pp 363ndash374 2001
[3] C Saradha and RMNachiappan ldquoEvaluation of diafenthiuron50WP (Polo) against whitefly Bemisia tabaci Genn (Aleyro-didae Homoptera) on Brinjal (Solanum mlongena)rdquo Pestologyvol 27 pp 12ndash14 2003
[4] J J Patel B H Patel P D Bhatt and A B Manghodia ldquoBio-efficacy of diafenthiuron 50 WP against sucking pests of bri-njal (Solanum melangena L)rdquo in Biodiversity and Insect PestManagement S Ignacimuthu and S Jayaraj Eds pp 57ndash58Narosa Publishing House New Delhi India 2006
[5] M A Javed and G A Matthews ldquoBioresidual and integratedpestmanagement status of a biorational agent and a novel insec-ticide against whitefly and its key parasitoidsrdquo InternationalJournal of Pest Management vol 48 no 1 pp 13ndash17 2002
[6] J R Scarpellani ldquoEffect of thiamethoxam and diafenthiuron tonymphs of whitefly Bemisia argentifolli on beansrdquo in Proceed-ings of the 21th International Conference of Entomology p 711Iguassu Falls Brazil August 2000
[7] A Noor Field evaluation of newer insecticides against suckingpests infesting in chillies in Western Rajasthan [PhD thesis]Department of Entomology Agricultural Research StationRAU campus Mandor Jodhpur 2001
[8] M H Tatagar H D Mohankumar R K Mesta and MShivaprasad ldquoBioefficacy of new molecules Pegasus 50 WP tochilli thrips Scirtothrips dorsalis (Hood) and mites Polyphago-tarsonemus latus (Banks)rdquo Pestology vol 36 no 2 pp 19ndash212012
[9] UPASI Seventy Nine Annual Report Edited by N Muraleedha-ran and R Rajkumar UPASI Tea Research Found 2005
[10] R Sudhakaran P Rajakumari and A Mohandhas ldquoEvaluationof newer insecticides Match 5 EC and Polo 50 SC on the controlof insect pests on cottonrdquo Pestology vol 19 pp 14ndash18 1995
8 Chromatography Research International
[11] K R Kranthi S Kranthi et al ldquoIRM-Revolutionising cottonpestmanagement in IndiardquoResistant PestManagement Newslet-ter vol 14 pp 33ndash36 2004
[12] I Ishaaya Z Mendelson and A R Horowitz ldquoToxicity andgrowth-suppression exerted by diafenthiuron in the sweet-potatowhiteflyBemisia tabacirdquoPhytoparasitica vol 21 pp 199ndash204 1993
[13] S Lingappa K Basavanagoud K A Kulkarni S P Roopaand D N Kambrekar ldquoThreat to vegetable production by dia-mondback moth and its management strategiesrdquo in DiseaseManagement in Fruits and Vegetables pp 357ndash396 SpringerAmsterdam The Netherlands 2004
[14] J Stanley S Chandrasekaran G Preetha and S KuttalamldquoToxicity of diafenthiuron to honey bees in laboratory semi-field and field conditionsrdquo PestManagement Science vol 66 no5 pp 505ndash510 2010
[15] J Drabek M Boger J Ehrenfreund et al ldquoNew thioureasas insecticidesrdquo in Recent Advances in the Chemistry of InsectControl II C Crobie Ed vol 79 of Special Publication pp 170ndash183 Royal Society of Chemistry Cambridge UK 1992
[16] H A Kadir and C O Knowles ldquoToxicological studies of thethiourea diafenthiuron in diamondback moths and two spottedspider mites and bulb mitesrdquo Journal of Economic Entomologyvol 84 pp 780ndash784 1991
[17] IUPACDetection and Significance of ActiveMetabolites of Agro-chemicals and Related Xenobiotics in Animals vol 67 of Editedby RM Hollingworth N Kurihara J Miyamoto S Otto andGD Paulson International Union of Pure and Applied Chem-istry 1995
[18] H Kayser and P Eilinger ldquoMetabolism of diafenthiuron bymicrosomal oxidation procide activation and inactivation asmechanisms contributing to selectivityrdquo Pest Management Sci-ence vol 57 pp 975ndash980 2001
[19] Y-S Keum J-H Kim Y-W Kim K Kim and Q X Li ldquoPhoto-degradation of diafenthiuron in waterrdquo Pest Management Sci-ence vol 58 no 5 pp 496ndash502 2002
[20] Y S Keum K H Liu J S Seo et al ldquoDissipation of foliarresidues of diafenthiuron and its metabolitesrdquo Bulletin of Envi-ronmental Contamination and Toxicology vol 68 no 6 pp845ndash851 2002
[21] CIBampRC ldquoCentral Insecticide Board andRegistrationCommit-teerdquo 2006 httpwwwcibrcnicin267rcdoc
[22] D Rajabaskar and A Regupathy ldquoPersistence of diafenthiuronin cardamomrdquo Pesticide Research Journal vol 20 pp 247ndash2492008
[23] S Navickiene A Aquino and D S S Bezerra ldquoA matrix solid-phase dispersion method for the extraction of seven pesticidesfrom mango and papayardquo Journal of Chromatographic Sciencevol 48 no 9 pp 750ndash754 2010
[24] APVMA ldquoThe standard MRL in food and animal feed stuffMay 2007 Maximum residue levels of Agricultural and Veteri-nary chemicals and associated substances in food commodi-tiesrdquo 2007 httpwwwapvmagovauresidues
[25] Table of MRLs for Agricultural Chemicals ldquoThe Japan FoodChemical Research Foundationrdquo 2010 httpwwwffcrorjp
[26] S Valarmathi and A Regupathy ldquoEvaluation of two ecofriendlyformulations of quinalphos aqua flow (AF) and colloidal sus-pension (CS) on cardamomresiduesrdquo in 14th International PlantProtection Congress (IPPC rsquo99) Jerusalem Israel July 1999
[27] D Rajabaskar Studies on the evaluation of IPMmodules againstConogethes punctiferalis Guenee and Sciothrips cardamomi
Ramk on cardamom [PhD thesis] Tamil Nadu AgriculturalUniversity Coimbatore India 2003
[28] A Regupathy R S S Kumar D Rajabaskar and K ChozhanldquoDetermination of residues of profenophos in cardamomrdquo inProceedings of National Seminar on Resource Management inPlant Protection during Twenty First Century Hyderabad India2002
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
Chromatography Research International 7
0
1
2
3
4
0 1 3 7 10
Log
resid
ues (
ppm
)
Period (days)
Linear (green capsules)Linear (cured capsules)Linear (moisture free basis)
Figure 3Dynamics of diafenthiuron (008) residues in cardamomcapsulesmdashExperiment I
0
1
2
3
4
0 1 3 7 10 15
Log
resid
ues (
ppm
)
Period (days)
Linear (green capsules)Linear (cured capsules)Linear (moisture free basis)
Figure 4 Dynamics of diafenthiuron (008) residues in car-damom capsulesmdashExperiment II
of residues in curing process (steaming and garbling) thereduction in weight should also be taken into account Themoisture content in green cardamom is about 70 percentSo when the capsules are driedcured the residues presentin 25 g of green cardamom sample will get concentrated inabout 7 g of cured capsules The dissipation of diafenthiuronis slower than the moisture loss during curing Thus thehigher residues of diafenthiuron in cured capsules than greencapsules obtained in the present study might be due to themoisture loss and high reduction in weight during curing
The dissipation pattern of diafenthiuron in cardamomgreen and cured samples is shown in Figures 3 and 4 Thedissipation rate was much faster in the present study whichis in line with the reports of Keum et al [19] stating veryhigh rate of degradation in Chinese cabbage The waitingperiod (119905MRL) for diafenthiuron was arrived at 550ndash669days in green and 701ndash713 days in cured capsules at therecommended dose of 008 percent This is lower than thereports made for profenofos 005 percent on green (1176days) and cured capsules (1082 days) [27]Thewaiting periodof lambda cyhalothrin (80 ppm) in cardamom was reportedas 88 to 109 days [28]The waiting period was reported to beseven days in green capsules of cardamom for diafenthiuronsprayed at 600 g ai haminus1 [22]
As mentioned earlier diafenthiuron is not approvedby Central Insecticide Board and Registration Committee
(CIBampRC) for spray in brinjal in view of long waiting periodof 10 days but approved for use in cardamom and subjectedfor fixing of tolerance limits [21] Picking of cardamomcapsules is carried out at an interval of 20ndash30 days As harvestbeing the focal point for enforcement of residue tolerancesthe suggested waiting period of seven days is safe enough tocontain the cardamom pests with diafenthiuron without theproblem of pesticide residues in harvestable produce
In conclusion it is clear that diafenthiuron dissipated toa level below detectable by seven days after spraying Usuallycardamomcapsules are harvested at an interval of 20ndash30 daysSo spraying of diafenthiuron does not possess any risk ofresidues in the harvestable produce if sprayed at least sevendays before harvesting
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
References
[1] H P Streibert J Drabek and A Rindisbacher ldquoDiafenthiurona new type of acaricideinsecticide for the control of the suckingpest complex in cotton and other cropsrdquo in Proceedings ofBrighton Crop Protection Conference Pests and Diseases BCPCFarnham pp 25ndash32 Syrrey UK 1988
[2] I Ishaaya S Kontsedalov D Mazirov and A R HorowitzldquoBiorational agents in IPM and IRM programs for controllingagricultural pestsrdquo Universiteit Gent vol 66 pp 363ndash374 2001
[3] C Saradha and RMNachiappan ldquoEvaluation of diafenthiuron50WP (Polo) against whitefly Bemisia tabaci Genn (Aleyro-didae Homoptera) on Brinjal (Solanum mlongena)rdquo Pestologyvol 27 pp 12ndash14 2003
[4] J J Patel B H Patel P D Bhatt and A B Manghodia ldquoBio-efficacy of diafenthiuron 50 WP against sucking pests of bri-njal (Solanum melangena L)rdquo in Biodiversity and Insect PestManagement S Ignacimuthu and S Jayaraj Eds pp 57ndash58Narosa Publishing House New Delhi India 2006
[5] M A Javed and G A Matthews ldquoBioresidual and integratedpestmanagement status of a biorational agent and a novel insec-ticide against whitefly and its key parasitoidsrdquo InternationalJournal of Pest Management vol 48 no 1 pp 13ndash17 2002
[6] J R Scarpellani ldquoEffect of thiamethoxam and diafenthiuron tonymphs of whitefly Bemisia argentifolli on beansrdquo in Proceed-ings of the 21th International Conference of Entomology p 711Iguassu Falls Brazil August 2000
[7] A Noor Field evaluation of newer insecticides against suckingpests infesting in chillies in Western Rajasthan [PhD thesis]Department of Entomology Agricultural Research StationRAU campus Mandor Jodhpur 2001
[8] M H Tatagar H D Mohankumar R K Mesta and MShivaprasad ldquoBioefficacy of new molecules Pegasus 50 WP tochilli thrips Scirtothrips dorsalis (Hood) and mites Polyphago-tarsonemus latus (Banks)rdquo Pestology vol 36 no 2 pp 19ndash212012
[9] UPASI Seventy Nine Annual Report Edited by N Muraleedha-ran and R Rajkumar UPASI Tea Research Found 2005
[10] R Sudhakaran P Rajakumari and A Mohandhas ldquoEvaluationof newer insecticides Match 5 EC and Polo 50 SC on the controlof insect pests on cottonrdquo Pestology vol 19 pp 14ndash18 1995
8 Chromatography Research International
[11] K R Kranthi S Kranthi et al ldquoIRM-Revolutionising cottonpestmanagement in IndiardquoResistant PestManagement Newslet-ter vol 14 pp 33ndash36 2004
[12] I Ishaaya Z Mendelson and A R Horowitz ldquoToxicity andgrowth-suppression exerted by diafenthiuron in the sweet-potatowhiteflyBemisia tabacirdquoPhytoparasitica vol 21 pp 199ndash204 1993
[13] S Lingappa K Basavanagoud K A Kulkarni S P Roopaand D N Kambrekar ldquoThreat to vegetable production by dia-mondback moth and its management strategiesrdquo in DiseaseManagement in Fruits and Vegetables pp 357ndash396 SpringerAmsterdam The Netherlands 2004
[14] J Stanley S Chandrasekaran G Preetha and S KuttalamldquoToxicity of diafenthiuron to honey bees in laboratory semi-field and field conditionsrdquo PestManagement Science vol 66 no5 pp 505ndash510 2010
[15] J Drabek M Boger J Ehrenfreund et al ldquoNew thioureasas insecticidesrdquo in Recent Advances in the Chemistry of InsectControl II C Crobie Ed vol 79 of Special Publication pp 170ndash183 Royal Society of Chemistry Cambridge UK 1992
[16] H A Kadir and C O Knowles ldquoToxicological studies of thethiourea diafenthiuron in diamondback moths and two spottedspider mites and bulb mitesrdquo Journal of Economic Entomologyvol 84 pp 780ndash784 1991
[17] IUPACDetection and Significance of ActiveMetabolites of Agro-chemicals and Related Xenobiotics in Animals vol 67 of Editedby RM Hollingworth N Kurihara J Miyamoto S Otto andGD Paulson International Union of Pure and Applied Chem-istry 1995
[18] H Kayser and P Eilinger ldquoMetabolism of diafenthiuron bymicrosomal oxidation procide activation and inactivation asmechanisms contributing to selectivityrdquo Pest Management Sci-ence vol 57 pp 975ndash980 2001
[19] Y-S Keum J-H Kim Y-W Kim K Kim and Q X Li ldquoPhoto-degradation of diafenthiuron in waterrdquo Pest Management Sci-ence vol 58 no 5 pp 496ndash502 2002
[20] Y S Keum K H Liu J S Seo et al ldquoDissipation of foliarresidues of diafenthiuron and its metabolitesrdquo Bulletin of Envi-ronmental Contamination and Toxicology vol 68 no 6 pp845ndash851 2002
[21] CIBampRC ldquoCentral Insecticide Board andRegistrationCommit-teerdquo 2006 httpwwwcibrcnicin267rcdoc
[22] D Rajabaskar and A Regupathy ldquoPersistence of diafenthiuronin cardamomrdquo Pesticide Research Journal vol 20 pp 247ndash2492008
[23] S Navickiene A Aquino and D S S Bezerra ldquoA matrix solid-phase dispersion method for the extraction of seven pesticidesfrom mango and papayardquo Journal of Chromatographic Sciencevol 48 no 9 pp 750ndash754 2010
[24] APVMA ldquoThe standard MRL in food and animal feed stuffMay 2007 Maximum residue levels of Agricultural and Veteri-nary chemicals and associated substances in food commodi-tiesrdquo 2007 httpwwwapvmagovauresidues
[25] Table of MRLs for Agricultural Chemicals ldquoThe Japan FoodChemical Research Foundationrdquo 2010 httpwwwffcrorjp
[26] S Valarmathi and A Regupathy ldquoEvaluation of two ecofriendlyformulations of quinalphos aqua flow (AF) and colloidal sus-pension (CS) on cardamomresiduesrdquo in 14th International PlantProtection Congress (IPPC rsquo99) Jerusalem Israel July 1999
[27] D Rajabaskar Studies on the evaluation of IPMmodules againstConogethes punctiferalis Guenee and Sciothrips cardamomi
Ramk on cardamom [PhD thesis] Tamil Nadu AgriculturalUniversity Coimbatore India 2003
[28] A Regupathy R S S Kumar D Rajabaskar and K ChozhanldquoDetermination of residues of profenophos in cardamomrdquo inProceedings of National Seminar on Resource Management inPlant Protection during Twenty First Century Hyderabad India2002
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
8 Chromatography Research International
[11] K R Kranthi S Kranthi et al ldquoIRM-Revolutionising cottonpestmanagement in IndiardquoResistant PestManagement Newslet-ter vol 14 pp 33ndash36 2004
[12] I Ishaaya Z Mendelson and A R Horowitz ldquoToxicity andgrowth-suppression exerted by diafenthiuron in the sweet-potatowhiteflyBemisia tabacirdquoPhytoparasitica vol 21 pp 199ndash204 1993
[13] S Lingappa K Basavanagoud K A Kulkarni S P Roopaand D N Kambrekar ldquoThreat to vegetable production by dia-mondback moth and its management strategiesrdquo in DiseaseManagement in Fruits and Vegetables pp 357ndash396 SpringerAmsterdam The Netherlands 2004
[14] J Stanley S Chandrasekaran G Preetha and S KuttalamldquoToxicity of diafenthiuron to honey bees in laboratory semi-field and field conditionsrdquo PestManagement Science vol 66 no5 pp 505ndash510 2010
[15] J Drabek M Boger J Ehrenfreund et al ldquoNew thioureasas insecticidesrdquo in Recent Advances in the Chemistry of InsectControl II C Crobie Ed vol 79 of Special Publication pp 170ndash183 Royal Society of Chemistry Cambridge UK 1992
[16] H A Kadir and C O Knowles ldquoToxicological studies of thethiourea diafenthiuron in diamondback moths and two spottedspider mites and bulb mitesrdquo Journal of Economic Entomologyvol 84 pp 780ndash784 1991
[17] IUPACDetection and Significance of ActiveMetabolites of Agro-chemicals and Related Xenobiotics in Animals vol 67 of Editedby RM Hollingworth N Kurihara J Miyamoto S Otto andGD Paulson International Union of Pure and Applied Chem-istry 1995
[18] H Kayser and P Eilinger ldquoMetabolism of diafenthiuron bymicrosomal oxidation procide activation and inactivation asmechanisms contributing to selectivityrdquo Pest Management Sci-ence vol 57 pp 975ndash980 2001
[19] Y-S Keum J-H Kim Y-W Kim K Kim and Q X Li ldquoPhoto-degradation of diafenthiuron in waterrdquo Pest Management Sci-ence vol 58 no 5 pp 496ndash502 2002
[20] Y S Keum K H Liu J S Seo et al ldquoDissipation of foliarresidues of diafenthiuron and its metabolitesrdquo Bulletin of Envi-ronmental Contamination and Toxicology vol 68 no 6 pp845ndash851 2002
[21] CIBampRC ldquoCentral Insecticide Board andRegistrationCommit-teerdquo 2006 httpwwwcibrcnicin267rcdoc
[22] D Rajabaskar and A Regupathy ldquoPersistence of diafenthiuronin cardamomrdquo Pesticide Research Journal vol 20 pp 247ndash2492008
[23] S Navickiene A Aquino and D S S Bezerra ldquoA matrix solid-phase dispersion method for the extraction of seven pesticidesfrom mango and papayardquo Journal of Chromatographic Sciencevol 48 no 9 pp 750ndash754 2010
[24] APVMA ldquoThe standard MRL in food and animal feed stuffMay 2007 Maximum residue levels of Agricultural and Veteri-nary chemicals and associated substances in food commodi-tiesrdquo 2007 httpwwwapvmagovauresidues
[25] Table of MRLs for Agricultural Chemicals ldquoThe Japan FoodChemical Research Foundationrdquo 2010 httpwwwffcrorjp
[26] S Valarmathi and A Regupathy ldquoEvaluation of two ecofriendlyformulations of quinalphos aqua flow (AF) and colloidal sus-pension (CS) on cardamomresiduesrdquo in 14th International PlantProtection Congress (IPPC rsquo99) Jerusalem Israel July 1999
[27] D Rajabaskar Studies on the evaluation of IPMmodules againstConogethes punctiferalis Guenee and Sciothrips cardamomi
Ramk on cardamom [PhD thesis] Tamil Nadu AgriculturalUniversity Coimbatore India 2003
[28] A Regupathy R S S Kumar D Rajabaskar and K ChozhanldquoDetermination of residues of profenophos in cardamomrdquo inProceedings of National Seminar on Resource Management inPlant Protection during Twenty First Century Hyderabad India2002
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
