Post on 12-Jul-2020
Hindawi Publishing CorporationJournal of ChemistryVolume 2013 Article ID 894020 6 pageshttpdxdoiorg1011552013894020
Research ArticleSpectrochemical Analysis of Soil around Leather TanningIndustry Using Laser Induced Breakdown Spectroscopy
Shakeel Ahmad Khan1 Muhammad Ibrahim1 Yasir Jamil2
Md Saiful Islam3 and Farhat Abbas1
1 Department of Environmental Sciences Government College University Faisalabad 38000 Pakistan2 Laser Spectroscopy Laboratory Department of Physics University of Agriculture Faisalabad 38040 Pakistan3 Department of Chemistry Universiti Putra Malaysia 43400 Serdang Selangor Malaysia
Correspondence should be addressed to Muhammad Ibrahim ebrahemmgmailcomand Md Saiful Islam mdsaifulscienceupmedumy
Received 28 July 2013 Accepted 2 September 2013
Academic Editor Athanasios Katsoyiannis
Copyright copy 2013 Shakeel Ahmad Khan et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited
We report the use of laser induced breakdown spectroscopy (LIBS) to determine the chromium contamination of soil due toeffluents from leather tanning industry in Kasur District of Punjab (+31∘610158402321
10158401015840
+74∘271015840162910158401015840
) in Pakistan Calibration curveswere constructed by indigenously prepared standard sample and fitting of curves by linear regressionThe limit of detection (LOD)was found to be 2371mg kgminus1 It has been found that the concentration of chromium in the soil is up to 839mg kgminus1 in vicinity ofeffluent drain and 1829mg kgminus1 in the area of old stagnant pool which is much higher than the safe limits Qualitative detection ofother elements like Na Cl Fe P and Si was done from LIBS spectra The leaching of soil contaminants due to seepage of industrialeffluents from deteriorating brick lined drains in horizontal direction has also been observed
1 Introduction
Management of industrial waste is a major concern especiallyin the developing countries Due to rapid growth of industrya huge amount of industrial waste is being dumped in the soilsurface resulting in ecodamaging effects Due to ignoranceabout environmental hazards high cost of treatment plantsand lack of effective enforcement of environmental controllaws very little attention is being given to proper disposalof industrial waste [1] Throwing waste water and dumpingsolid waste are causing serious health and environmentalproblems
In the developing countries like Pakistan very little workhas been done for effective environmental monitoring meth-ods despite the urgency of the matter There have been veryfew reports in the literature about the environmental studiesin the region Mubin et al [2] analyzed ten main industries ofKarachi (Pakistan) and found that the leather industry wasthe major contributor towards damaging the environment
due to toxicity in untreated industrial waste water Forcingthis industry to have treatment plants could reduce problemup to 25 associated with industrial effluents
The industrial waste contains large amount of contami-nants like heavy metal which may enter into the food chainthrough vegetation in dumping areas and the areas beingirrigated by the untreatedsemitreated waste water from theindustry [3] It was found that vegetation grown with wastewater from industry contained high concentration of heavymetals like Pd Fe Cu Zn and Cr [4] Chromium is apollutant that is being disposed due to several industrial pro-cesses like chromium plating stainless steel manufacturingwood treatment paint industry and tanning industry Thechromium containing effluents from tannery industry maycause serious environmental problems US EnvironmentalProtection Agency has designated chromium (Cr) as prioritypollutant due to its adverse effects on human health [5]Although Cr III is essential dietary mineral [6] but Cr VIis toxic form of the element mostly found in the compound
2 Journal of Chemistry
form made artificially for the use in different industriesThe exposure to hexavalent chromium can cause adverseeffects to warm blooded organisms [7] Occupational Safetyand Health Administration (OSHA) [8] has reported lungcancer irritation or damaged nose throat and respiratorytract due to breathing in chromium polluted environmentalcondition and eyes and skin rash may be the result of directcontact of chromium The maximum dose limit set at workplace for eight hours is 5 120583gmminus3 in air in the form of dustor particles Cr VI depresses the biological activity and theenzymatic activity of microorganisms by modifying theirliving environment [9] The soil dying out by the tanningindustrial waste can contain chromium concentration muchhigher than safe limits set by US Environmental ProtectionAgency
Malek et al [10] studied differentmechanisms for removalof Cr from solid leather industrial waste for its reuse andreported 95 extraction capability Irfan et al [11] studiedthe removal of Cr fromwastewater usingThespesia populeneawith changing environmental conditions of pH biomassdose biomass particle size and agitation time The ram-pant discharge of untreated water from tanning industry isincreasing level of chromium in soil This causes perfora-tion and bronchogenic carcinoma to continuously exposedhumans Chicken feeds prepared from chromium containingproteins rich tanneries solid wastes are likely to cause directchromium entry into food chain [12] Inclusion of chromiumin the environment due to industrial activities demands atechnique that can be used to monitor continuously theindustrial effluents and waste in situ and in lab Laser inducedbreakdown spectroscopy (LIBS) is atomic emission spectro-scopic technique in which a laser beam is focused on thetargetmaterial by a focusing lens which ablates somematerial(hundreds of nanogram to few microgram) from the targetsurface producing microplasma which gives characteristicemission of sample on cooling [13] The emitted radiationsare analyzed by spectrometer for elemental detection Dueto simple arrangement almost no sample preparation rapidanalysis and capability of analyzing all states of matter (solidliquid or gaseous) LIBS technique is finding its niche amongthe modern spectroscopic techniques rapidly The emissionspectrum can be used both for qualitative and quantitativeanalysis [14] N K Rai and A K Rai [15] studied Cr con-centration in liquids effluents from chromium electroplatingindustry using LIBS
LIBS is one of those spectroscopic techniques that areconsidered to have the capability of determining elementsdown trace level [12 13] It is nondestructive and is ideal forthe analysis of multielements simultaneously without muchsample preparation With the help of fiber optics LIBS can beused to study hazardous environments from where carryingsample to laboratory is difficult and remote analysis ispossible as only optical access is required [13] The techniquecan be used both for metallic and nonmetallic analytes withlow limit of detection [16] The specific objectives of theseinvestigations include how LIBS can be used for analyticalanalysis of samples rapidly and without involving muchsample preparation and how it can be used as in situ andonline analytical technique
NdYag laser
Fiber optics
focusing lensQuartz
Collecting optics
SpectrometerData acquisition system
Delay generator
Mirror
Power supply
Plasma
Target
Figure 1 Experimental setup
2 Materials and Methods
The experimental setup for the analysis of soil sample byLIBS is shown in Figure 1 A short pulsed (5 ns) Q-switchedNdYag laser operating at the fundamental mode (1064 nm)having 10Hz repetition rate was used A quartz biconvexlens of focal length 10 cm was used for focusing the laserbeam on pelletized sample The sample was mounted on arotating stage rotating at 12 RPM to provide a fresh surfacefor each of the incident laser pulse The light emitted by thehot plasma was fed to symmetrical Czerny-Turner designspectrometer (Avantes AvaSpec-3648 USB 2 Dual channel)through collecting optics including collecting lens andfiber optics It covers the spectrum range from 300 nm to750 nm with optical resolution of 007 nm Spectrometeris connected to a computer for storing acquired data andto a digital delay generator (DG 535 of Stanford ResearchSystem) for triggering it at a specified delay after laser pulseto start acquisition of data The Avaspec-3648 spectrometerwas operated by using Avasoft software to record spectrumThe data was analyzed by graphing software Origin Peakswere identified and compared with NIST (National Instituteof Standard and Technology) atomic spectrum database(httpphysicsnistgovPhysRefDataASDlines formhtml)to identify elemental composition of the sample [17]
Samples of soil were collected from industrial area ofKasur a district of Punjab Pakistan (Google maps shown inFigure 2) Twenty-four samples were collected from differentlocations (around +31∘61015840232110158401015840 +74∘271015840162910158401015840) First set ofsix samples was collected in the vicinity of discharge theother three sets of samples each set of six samples werecollected from 20 meter 50m and 200m from main drainMost of the industry located there is tanning industry whereraw hides are processed to finished leather UNDP initiatedKasur Tanneries Pollution Control Project in collaborationwith federal government of the Pakistan Provincial govern-ment of the Punjab and local tannery operators Due to thesefacilities stagnant pools have been vanished in the localityreducing hazardous materials in the surrounding
Each sample was packed in polythene bags Samples weredried at 60∘C for 6 hour in oven (Shell DownManufacturingInc Portland Oregon) The samples were grinded in agatemortar and pestle and then pellets were made of each sampleat 4000 bar for 5 minutes by adding polyvinyl alcohol (PVA)
Journal of Chemistry 3
Figure 2 Sampling area near Kasur district of Punjab Pakistan
3 Results and Discussion
31 Calibration Curve Instrumental calibration is an essen-tial stage for quantitative analysis It gives the relationshipbetween response of the instrument (integrated intensityin arb units) and analyte concentration (in mg kgminus1) Weuse five indigenously prepared standard samples by mixingwell grinded and sieved known ratio of potassium chro-mate (K
2CrO4gt 99 pure and 19419 molecular weight
supplied by Santa Cruz Biotechnology Inc) and standardsoil (chromium-free soil) obtained from Institute of Soil andEnvironmental Sciences University of Agriculture Faisal-abad The standard soil was also confirmed by inductivelycoupled plasma-optical emission spectroscopy (ICP-OES) forabsence of chromium We started with mixing of 1865 g(measured by scalemodel ATY224 from ShimadzuCorpora-tion having readability of 01mg) of K
2CrO4in 1000 g of clean
soil to get standard sample containing Cr 500mg kgminus1 Thewhole sample was mixed thoroughly until a homogenizedsample was obtained then 100 g of sample was taken outof the homogenized sample for analysis After that 1685 gof powdered salt was added more to the remaining mixedsample to get standard containing Cr 1000mg kgminus1 In thisway we prepared five standard samples each of 100 g Threerepresentative pellets from each sample were made to getaverage of spectra (chromium line 42748 nm) for eachstandard sample Calibration curve (shown in Figure 3) wasconstructed between Cr concentration and integrated inten-sity of the signal for 42748 nm avoiding self-absorption andbroadening effects whichmay rise in case of considering peakintensity for quantitative analysis The linear regression coef-ficient also called coefficient of determination 1198772 = 09789showed the good linear relationship between concentrationand integrated intensity
The analysis of variance (ANOVA) table was constructedfor this linear regression model given in Table 1 to furthercheck the statistical dependence of concentration of analyteon integrated intensity
The small 119875-value in the ANOVA table shows that resultshave not happened by chance but 119910 (integrated intensity)
Table 1 ANOVA table for Cr calibration curve
Item Degrees offreedom
Sum ofsquares
Meansquare 119865 statistic 119875 value
Model 1 556960 556960 18679068 84 times 10minus4
Error 3 89452 298173333Total 4 5659052
R2= 09789
1400
1200
1000
800
600
400
200
00 500 1000 1500 2000 2500
Cr concentration (mgkg)
Inte
grat
ed in
tens
ity (a
u)
Y = 814 + 0472 lowast X
Figure 3 Calibration curve for Cr in soil
and 119909 (analyte concentration) parameters are strongly inter-related
The limit of detection [18] for Cr was found by using thefollowing
LOD =3radic1198782
+ 1198782
119886
+ (119886119887)2
lowast 1198782
119887
119887
(1)
where 119878 is the standard deviation of calibration data 119886is the intercept of the calibration curve at zero analyteconcentration 119878
119886is the error in the intercept and 119878
119887is
the indetermination on the slope of the calibration curveThe value of LOD was found 2371mg kgminus1 well below thedetected values in the region
The LIBS spectrum of chromium-free soil sample isshown in Figure 4(a) In Figure 4(b) emission lines ofiron (35465 nm) chromium (42748 nm) phosphorus(519141 nm) sodium (58897 nm) chlorine (49957 nm) andso forth were identified in the spectrum Chromium (Cr) isfound in tanning industry effluents due to the use of chromealum and chromium(III) sulphate in chrome tanning ofleather Due to its solubility it is mixed with waste water andis flushed out mostly without any effort of chrome recovery
The concentration of the Cr in the soil samples wascalculated in the area using calibration curve and it wasfound that the concentration of Cr varies randomly fromthe minimum value of 128mg kgminus1 to the maximum value of1829mg kgminus1 with mean value of 468mg kgminus1 The range ofconcentration is 1701mg kgminus1 and standard deviation in theconcentration in samples is 37144mg kgminus1 The value of
4 Journal of Chemistry
600
300
0300 400 500 600 700
633
57 A
l-II
589
43 Z
n-II
518
36 M
g-I
441
73 T
i-I
392
77 F
e-I
317
93 C
a-II
Wavelength (nm)
Inte
nsity
(au
)
(a)
723
61 (C
-II)
634
75 (S
i-II)
588
99 (N
a-I)
(N-I
I)499
57 (C
l-II)
427
48 (C
r-I)
427
48 (C
r-I)
395
43 (F
e-I)
395
43 (F
e-I)
317
39 519
10 (P
-II)
600
600
900
300
300
390 400 410 420 430
0
0
300 400 500 600 700Wavelength (nm)
Wavelength (nm)
Inte
nsity
(au
)
Inte
nsity
(au
)
(b)
Figure 4 (a) Spectrum of unpolluted soil from soil sciences department (UAF) (b) Spectrum of polluted soil from sampling area
Cr concentration near the effluent drain was found to be839mg kgminus1 maximum but at the location of old stagnantpool concentration of the Cr is very high up to 1829mg kgminus1The random distribution of Cr (shown in Figure 5) in soilin the area is due to unplanned distribution of the tanneriesin the area and due to deteriorating uneven constructionconditions and broken brick lining of the drains and textureof the soil causing seepage of polluted water
The elements which can be detected in the sample alongwith their possible transitions are given in Table 2 Theobserved difference is within the narrow bandwidth of thespectrometer
The elements sodium and chlorine were found in thesoil around the tanneries because sodium chloride (NaCl) isused in large quantity for skin preservation or the picklingprocess of leather Since it is highly soluble and stable soeffluent treatment does not much reduce its concentrationand it remains in the effluent from which it is leached intothe soil to a reasonable distance Increased salt concentrationin the water is becoming a serious issue to the environment
Chlorides have adverse effects to the growth of plantsbacteria and fish in surface water When this saline wateris used for irrigation purpose soil salinity increases and cropyield decreases Calcium level in soil has high concentrationof sodium which may reduce plant growth [19] This type ofsoil is called sodic soil The plants ability of water extractionfrom saline soil is also reduced
4 Conclusion
Laser induced breakdown spectroscopy can be used asqualitative and quantitative analytical technique with verylow limit of detection (in our study it was found to be2371mg kgminus1) The study depicted the high concentration ofCr in the soil which in turn can be uptaken by plants andfood crops in the area and ultimately can be introduced inthe food chain It has been observed that in the presence oforganic acids (citric and oxalic) uptake of Cr may increaseand can be toxic for the community The salinity of the soil isalso increasing due to dissolved salts in the effluents causing
Journal of Chemistry 5
Table 2 Important elements found in different samples with their possible transitions
Element symbol Wavelength (NIST) (nm) Wavelength observed (nm) Difference (nm) ConfigurationFe I 395465 39543 0035 3p64f mdash 3p66fCr I 4626174 46261 00074 3d44s2 mdash 3d4(5D)4s4p(3P∘)Cl II 4995473 49957 00227 3s23p3(2D∘)3d mdash 3s23p3(2D∘)4pP II 519141 51910 0041 3s23p4s mdash 3s23p4pN II 5674 56738 0020 2s22p3p mdash 2s22p3dNa I 5889950943 58897 0025094 2p63s mdash 2p63pSi II 63471 63475 0040 1s22p4p mdash 1s22p4d
Sam
ple n
umbe
r for
each
loca
tion
Distance from the point source
Conc
entra
tion
(ppm
) Clipped gr
aph
for clar
ity in
random va
riatio
n
600
400
2000
50100
150200
2
4
6
Figure 5 Variation of Cr concentration with distance for differentsamples
low yield of crop in those areas The soil remediation processis needed to avoid hazards of heavymetal pollution LIBS canbe used for onlinemonitoring of the waste treatment facilitieseffectively and soil remediation processes due to its rapid andmultielemental analysis capabilities
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgments
The data presented here is part of thesis of first author atGovernment College University Faisalabad (Pakistan) Theauthors are thankful to the Higher Education Commis-sion (HEC) Pakistan for providing scholarship for PhDin Environmental Science The authors are also thankfulto the Institute of Soil and Environmental Sciences Uni-versity of Agriculture Faisalabad for providing standardsoil samples This research was partially supported by theCOMSTECH-TWAS Joint Research Grant Program (Grantno 09-255RGEASAS C UNESCO FR 3240231220)
References
[1] A A Belay ldquoImpacts of chromium from tannery effluent andevaluation of alternative treatment optionsrdquo Journal of Environ-mental Protection vol 1 pp 53ndash58 2010
[2] S Mubin S Gul M I A Khokhar and M Ashraf ldquoStatisticalsolution for the industrial waste problemrdquo Journal of Drainageand Water Management vol 6 no 2 pp 55ndash68 2002
[3] M A Khan A Wajid S Noor F K Khattak S Akhter and IU Rahman ldquoEffect of soil contamination on some heavymetalscontent of Cannabis sativardquo Journal of the Chemical Society ofPakistan vol 30 no 6 pp 805ndash809 2008
[4] K Rehman S Ashraf U Rashid et al ldquoComparison of proxi-mate and heavy metal contents of vegetables grown with freshand wastewaterrdquo Pakistan Journal of Botany vol 45 no 2 pp391ndash400 2013
[5] E T Oppelt In Situ Treatment of Soil and Groundwater Con-taminated with Chromium Technical Resource Guide 2000
[6] Z Krejpcio ldquoEssentiality of chromium for human nutrition andhealthrdquoPolish Journal of Environmental Studies vol 10 no 6 pp399ndash404 2001
[7] R Eisler ldquoChromium hazards to fish wildlife and invertebratesa synoptic Reviewrdquo Biological Report US Fish amp Wildlife Ser-vice Laurel Md USA 1986
[8] OSHA-Occupational Safety and Health Administration SmallEntity Compliance Guide for the Hexavalent Chromium Stan-dards US Department of Labour 2006
[9] J Wyszkowska ldquoSoil contamination by chromium and its enzy-matic activity and yieldingrdquo Polish Journal of EnvironmentalStudies vol 11 no 1 pp 79ndash84 2002
[10] A Malek M Hachemi and V Didier ldquoNew approach of depol-lution of solid chromium leather waste by the use of organicchelates Economical and environmental impactsrdquo Journal ofHazardous Materials vol 170 no 1 pp 156ndash162 2009
[11] M Irfan M Ibrahim U Rashid M Nisa and A Al-MuhtasebldquoOptimization of Cr(III) removal from wastewater using Thes-pesia populenea particles by response surface methodologyrdquoAsian Journal of Chemistry vol 25 no 15 2013
[12] M A Khwaja S Nasreen and M R Jan ldquoStatus and problemsof hazardous effluents from tanneries in NWFPrdquo in Proceed-ings of the Pacific Basin Conference on Hazardous Waste p 5701998
[13] D A Cremers and L J Radziemski Handbook of BreakdownSpectroscopy John Wiley amp Sons 2006
[14] J P Singh and S N Thakur Eds Laser-Induced BreakdownSpectroscopy Elsevier BV 2007
[15] N K Rai and A K Rai ldquoLIBS-An efficient approach for thedetermination of Cr in industrial wastewaterrdquo Journal of Haz-ardous Materials vol 150 no 3 pp 835ndash838 2008
6 Journal of Chemistry
[16] N K Rai A K Rai A Kumar and S N Thakur ldquoDetectionsensitivity of laser-induced breakdown spectroscopy for Cr IIin liquid samplesrdquo Applied Optics vol 47 no 31 pp G105ndashG1112008
[17] A Kramida Y Ralchenko J Reader et al ldquoNIST atomic spec-tra database (ver 50)rdquo 2012 httpphysicsnistgovPhysRef-DataASD
[18] A Elhassan G Cristoforetti and S Legnaioli ldquoLIBS calibrationcurves and determination of limits of detection (LOD) in singleand double pulse configuration for quantitative LIBS analysisof bronzesrdquo in Proceedings of the International Conference inConservation Strategies for Saving Indoor Metallic Collectionspp 72ndash77 2007
[19] SMA Rahim SHasnain and J Farkhanda ldquoEffect of calciummagnesium sodium and potassium on farm plantations of var-ious agroeclogical zones of Punjab PakistanrdquoAfrican Journal ofPlant Science vol 5 no 5 pp 450ndash459 2011
Submit your manuscripts athttpwwwhindawicom
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom
International Journal of
Analytical ChemistryVolume 2013
ISRN Chromatography
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2013
The Scientific World Journal
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
CatalystsJournal of
ISRN Analytical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Advances in
Physical Chemistry
ISRN Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
ISRN Inorganic Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2013
ISRN Organic Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Journal of
Spectroscopy
2 Journal of Chemistry
form made artificially for the use in different industriesThe exposure to hexavalent chromium can cause adverseeffects to warm blooded organisms [7] Occupational Safetyand Health Administration (OSHA) [8] has reported lungcancer irritation or damaged nose throat and respiratorytract due to breathing in chromium polluted environmentalcondition and eyes and skin rash may be the result of directcontact of chromium The maximum dose limit set at workplace for eight hours is 5 120583gmminus3 in air in the form of dustor particles Cr VI depresses the biological activity and theenzymatic activity of microorganisms by modifying theirliving environment [9] The soil dying out by the tanningindustrial waste can contain chromium concentration muchhigher than safe limits set by US Environmental ProtectionAgency
Malek et al [10] studied differentmechanisms for removalof Cr from solid leather industrial waste for its reuse andreported 95 extraction capability Irfan et al [11] studiedthe removal of Cr fromwastewater usingThespesia populeneawith changing environmental conditions of pH biomassdose biomass particle size and agitation time The ram-pant discharge of untreated water from tanning industry isincreasing level of chromium in soil This causes perfora-tion and bronchogenic carcinoma to continuously exposedhumans Chicken feeds prepared from chromium containingproteins rich tanneries solid wastes are likely to cause directchromium entry into food chain [12] Inclusion of chromiumin the environment due to industrial activities demands atechnique that can be used to monitor continuously theindustrial effluents and waste in situ and in lab Laser inducedbreakdown spectroscopy (LIBS) is atomic emission spectro-scopic technique in which a laser beam is focused on thetargetmaterial by a focusing lens which ablates somematerial(hundreds of nanogram to few microgram) from the targetsurface producing microplasma which gives characteristicemission of sample on cooling [13] The emitted radiationsare analyzed by spectrometer for elemental detection Dueto simple arrangement almost no sample preparation rapidanalysis and capability of analyzing all states of matter (solidliquid or gaseous) LIBS technique is finding its niche amongthe modern spectroscopic techniques rapidly The emissionspectrum can be used both for qualitative and quantitativeanalysis [14] N K Rai and A K Rai [15] studied Cr con-centration in liquids effluents from chromium electroplatingindustry using LIBS
LIBS is one of those spectroscopic techniques that areconsidered to have the capability of determining elementsdown trace level [12 13] It is nondestructive and is ideal forthe analysis of multielements simultaneously without muchsample preparation With the help of fiber optics LIBS can beused to study hazardous environments from where carryingsample to laboratory is difficult and remote analysis ispossible as only optical access is required [13] The techniquecan be used both for metallic and nonmetallic analytes withlow limit of detection [16] The specific objectives of theseinvestigations include how LIBS can be used for analyticalanalysis of samples rapidly and without involving muchsample preparation and how it can be used as in situ andonline analytical technique
NdYag laser
Fiber optics
focusing lensQuartz
Collecting optics
SpectrometerData acquisition system
Delay generator
Mirror
Power supply
Plasma
Target
Figure 1 Experimental setup
2 Materials and Methods
The experimental setup for the analysis of soil sample byLIBS is shown in Figure 1 A short pulsed (5 ns) Q-switchedNdYag laser operating at the fundamental mode (1064 nm)having 10Hz repetition rate was used A quartz biconvexlens of focal length 10 cm was used for focusing the laserbeam on pelletized sample The sample was mounted on arotating stage rotating at 12 RPM to provide a fresh surfacefor each of the incident laser pulse The light emitted by thehot plasma was fed to symmetrical Czerny-Turner designspectrometer (Avantes AvaSpec-3648 USB 2 Dual channel)through collecting optics including collecting lens andfiber optics It covers the spectrum range from 300 nm to750 nm with optical resolution of 007 nm Spectrometeris connected to a computer for storing acquired data andto a digital delay generator (DG 535 of Stanford ResearchSystem) for triggering it at a specified delay after laser pulseto start acquisition of data The Avaspec-3648 spectrometerwas operated by using Avasoft software to record spectrumThe data was analyzed by graphing software Origin Peakswere identified and compared with NIST (National Instituteof Standard and Technology) atomic spectrum database(httpphysicsnistgovPhysRefDataASDlines formhtml)to identify elemental composition of the sample [17]
Samples of soil were collected from industrial area ofKasur a district of Punjab Pakistan (Google maps shown inFigure 2) Twenty-four samples were collected from differentlocations (around +31∘61015840232110158401015840 +74∘271015840162910158401015840) First set ofsix samples was collected in the vicinity of discharge theother three sets of samples each set of six samples werecollected from 20 meter 50m and 200m from main drainMost of the industry located there is tanning industry whereraw hides are processed to finished leather UNDP initiatedKasur Tanneries Pollution Control Project in collaborationwith federal government of the Pakistan Provincial govern-ment of the Punjab and local tannery operators Due to thesefacilities stagnant pools have been vanished in the localityreducing hazardous materials in the surrounding
Each sample was packed in polythene bags Samples weredried at 60∘C for 6 hour in oven (Shell DownManufacturingInc Portland Oregon) The samples were grinded in agatemortar and pestle and then pellets were made of each sampleat 4000 bar for 5 minutes by adding polyvinyl alcohol (PVA)
Journal of Chemistry 3
Figure 2 Sampling area near Kasur district of Punjab Pakistan
3 Results and Discussion
31 Calibration Curve Instrumental calibration is an essen-tial stage for quantitative analysis It gives the relationshipbetween response of the instrument (integrated intensityin arb units) and analyte concentration (in mg kgminus1) Weuse five indigenously prepared standard samples by mixingwell grinded and sieved known ratio of potassium chro-mate (K
2CrO4gt 99 pure and 19419 molecular weight
supplied by Santa Cruz Biotechnology Inc) and standardsoil (chromium-free soil) obtained from Institute of Soil andEnvironmental Sciences University of Agriculture Faisal-abad The standard soil was also confirmed by inductivelycoupled plasma-optical emission spectroscopy (ICP-OES) forabsence of chromium We started with mixing of 1865 g(measured by scalemodel ATY224 from ShimadzuCorpora-tion having readability of 01mg) of K
2CrO4in 1000 g of clean
soil to get standard sample containing Cr 500mg kgminus1 Thewhole sample was mixed thoroughly until a homogenizedsample was obtained then 100 g of sample was taken outof the homogenized sample for analysis After that 1685 gof powdered salt was added more to the remaining mixedsample to get standard containing Cr 1000mg kgminus1 In thisway we prepared five standard samples each of 100 g Threerepresentative pellets from each sample were made to getaverage of spectra (chromium line 42748 nm) for eachstandard sample Calibration curve (shown in Figure 3) wasconstructed between Cr concentration and integrated inten-sity of the signal for 42748 nm avoiding self-absorption andbroadening effects whichmay rise in case of considering peakintensity for quantitative analysis The linear regression coef-ficient also called coefficient of determination 1198772 = 09789showed the good linear relationship between concentrationand integrated intensity
The analysis of variance (ANOVA) table was constructedfor this linear regression model given in Table 1 to furthercheck the statistical dependence of concentration of analyteon integrated intensity
The small 119875-value in the ANOVA table shows that resultshave not happened by chance but 119910 (integrated intensity)
Table 1 ANOVA table for Cr calibration curve
Item Degrees offreedom
Sum ofsquares
Meansquare 119865 statistic 119875 value
Model 1 556960 556960 18679068 84 times 10minus4
Error 3 89452 298173333Total 4 5659052
R2= 09789
1400
1200
1000
800
600
400
200
00 500 1000 1500 2000 2500
Cr concentration (mgkg)
Inte
grat
ed in
tens
ity (a
u)
Y = 814 + 0472 lowast X
Figure 3 Calibration curve for Cr in soil
and 119909 (analyte concentration) parameters are strongly inter-related
The limit of detection [18] for Cr was found by using thefollowing
LOD =3radic1198782
+ 1198782
119886
+ (119886119887)2
lowast 1198782
119887
119887
(1)
where 119878 is the standard deviation of calibration data 119886is the intercept of the calibration curve at zero analyteconcentration 119878
119886is the error in the intercept and 119878
119887is
the indetermination on the slope of the calibration curveThe value of LOD was found 2371mg kgminus1 well below thedetected values in the region
The LIBS spectrum of chromium-free soil sample isshown in Figure 4(a) In Figure 4(b) emission lines ofiron (35465 nm) chromium (42748 nm) phosphorus(519141 nm) sodium (58897 nm) chlorine (49957 nm) andso forth were identified in the spectrum Chromium (Cr) isfound in tanning industry effluents due to the use of chromealum and chromium(III) sulphate in chrome tanning ofleather Due to its solubility it is mixed with waste water andis flushed out mostly without any effort of chrome recovery
The concentration of the Cr in the soil samples wascalculated in the area using calibration curve and it wasfound that the concentration of Cr varies randomly fromthe minimum value of 128mg kgminus1 to the maximum value of1829mg kgminus1 with mean value of 468mg kgminus1 The range ofconcentration is 1701mg kgminus1 and standard deviation in theconcentration in samples is 37144mg kgminus1 The value of
4 Journal of Chemistry
600
300
0300 400 500 600 700
633
57 A
l-II
589
43 Z
n-II
518
36 M
g-I
441
73 T
i-I
392
77 F
e-I
317
93 C
a-II
Wavelength (nm)
Inte
nsity
(au
)
(a)
723
61 (C
-II)
634
75 (S
i-II)
588
99 (N
a-I)
(N-I
I)499
57 (C
l-II)
427
48 (C
r-I)
427
48 (C
r-I)
395
43 (F
e-I)
395
43 (F
e-I)
317
39 519
10 (P
-II)
600
600
900
300
300
390 400 410 420 430
0
0
300 400 500 600 700Wavelength (nm)
Wavelength (nm)
Inte
nsity
(au
)
Inte
nsity
(au
)
(b)
Figure 4 (a) Spectrum of unpolluted soil from soil sciences department (UAF) (b) Spectrum of polluted soil from sampling area
Cr concentration near the effluent drain was found to be839mg kgminus1 maximum but at the location of old stagnantpool concentration of the Cr is very high up to 1829mg kgminus1The random distribution of Cr (shown in Figure 5) in soilin the area is due to unplanned distribution of the tanneriesin the area and due to deteriorating uneven constructionconditions and broken brick lining of the drains and textureof the soil causing seepage of polluted water
The elements which can be detected in the sample alongwith their possible transitions are given in Table 2 Theobserved difference is within the narrow bandwidth of thespectrometer
The elements sodium and chlorine were found in thesoil around the tanneries because sodium chloride (NaCl) isused in large quantity for skin preservation or the picklingprocess of leather Since it is highly soluble and stable soeffluent treatment does not much reduce its concentrationand it remains in the effluent from which it is leached intothe soil to a reasonable distance Increased salt concentrationin the water is becoming a serious issue to the environment
Chlorides have adverse effects to the growth of plantsbacteria and fish in surface water When this saline wateris used for irrigation purpose soil salinity increases and cropyield decreases Calcium level in soil has high concentrationof sodium which may reduce plant growth [19] This type ofsoil is called sodic soil The plants ability of water extractionfrom saline soil is also reduced
4 Conclusion
Laser induced breakdown spectroscopy can be used asqualitative and quantitative analytical technique with verylow limit of detection (in our study it was found to be2371mg kgminus1) The study depicted the high concentration ofCr in the soil which in turn can be uptaken by plants andfood crops in the area and ultimately can be introduced inthe food chain It has been observed that in the presence oforganic acids (citric and oxalic) uptake of Cr may increaseand can be toxic for the community The salinity of the soil isalso increasing due to dissolved salts in the effluents causing
Journal of Chemistry 5
Table 2 Important elements found in different samples with their possible transitions
Element symbol Wavelength (NIST) (nm) Wavelength observed (nm) Difference (nm) ConfigurationFe I 395465 39543 0035 3p64f mdash 3p66fCr I 4626174 46261 00074 3d44s2 mdash 3d4(5D)4s4p(3P∘)Cl II 4995473 49957 00227 3s23p3(2D∘)3d mdash 3s23p3(2D∘)4pP II 519141 51910 0041 3s23p4s mdash 3s23p4pN II 5674 56738 0020 2s22p3p mdash 2s22p3dNa I 5889950943 58897 0025094 2p63s mdash 2p63pSi II 63471 63475 0040 1s22p4p mdash 1s22p4d
Sam
ple n
umbe
r for
each
loca
tion
Distance from the point source
Conc
entra
tion
(ppm
) Clipped gr
aph
for clar
ity in
random va
riatio
n
600
400
2000
50100
150200
2
4
6
Figure 5 Variation of Cr concentration with distance for differentsamples
low yield of crop in those areas The soil remediation processis needed to avoid hazards of heavymetal pollution LIBS canbe used for onlinemonitoring of the waste treatment facilitieseffectively and soil remediation processes due to its rapid andmultielemental analysis capabilities
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgments
The data presented here is part of thesis of first author atGovernment College University Faisalabad (Pakistan) Theauthors are thankful to the Higher Education Commis-sion (HEC) Pakistan for providing scholarship for PhDin Environmental Science The authors are also thankfulto the Institute of Soil and Environmental Sciences Uni-versity of Agriculture Faisalabad for providing standardsoil samples This research was partially supported by theCOMSTECH-TWAS Joint Research Grant Program (Grantno 09-255RGEASAS C UNESCO FR 3240231220)
References
[1] A A Belay ldquoImpacts of chromium from tannery effluent andevaluation of alternative treatment optionsrdquo Journal of Environ-mental Protection vol 1 pp 53ndash58 2010
[2] S Mubin S Gul M I A Khokhar and M Ashraf ldquoStatisticalsolution for the industrial waste problemrdquo Journal of Drainageand Water Management vol 6 no 2 pp 55ndash68 2002
[3] M A Khan A Wajid S Noor F K Khattak S Akhter and IU Rahman ldquoEffect of soil contamination on some heavymetalscontent of Cannabis sativardquo Journal of the Chemical Society ofPakistan vol 30 no 6 pp 805ndash809 2008
[4] K Rehman S Ashraf U Rashid et al ldquoComparison of proxi-mate and heavy metal contents of vegetables grown with freshand wastewaterrdquo Pakistan Journal of Botany vol 45 no 2 pp391ndash400 2013
[5] E T Oppelt In Situ Treatment of Soil and Groundwater Con-taminated with Chromium Technical Resource Guide 2000
[6] Z Krejpcio ldquoEssentiality of chromium for human nutrition andhealthrdquoPolish Journal of Environmental Studies vol 10 no 6 pp399ndash404 2001
[7] R Eisler ldquoChromium hazards to fish wildlife and invertebratesa synoptic Reviewrdquo Biological Report US Fish amp Wildlife Ser-vice Laurel Md USA 1986
[8] OSHA-Occupational Safety and Health Administration SmallEntity Compliance Guide for the Hexavalent Chromium Stan-dards US Department of Labour 2006
[9] J Wyszkowska ldquoSoil contamination by chromium and its enzy-matic activity and yieldingrdquo Polish Journal of EnvironmentalStudies vol 11 no 1 pp 79ndash84 2002
[10] A Malek M Hachemi and V Didier ldquoNew approach of depol-lution of solid chromium leather waste by the use of organicchelates Economical and environmental impactsrdquo Journal ofHazardous Materials vol 170 no 1 pp 156ndash162 2009
[11] M Irfan M Ibrahim U Rashid M Nisa and A Al-MuhtasebldquoOptimization of Cr(III) removal from wastewater using Thes-pesia populenea particles by response surface methodologyrdquoAsian Journal of Chemistry vol 25 no 15 2013
[12] M A Khwaja S Nasreen and M R Jan ldquoStatus and problemsof hazardous effluents from tanneries in NWFPrdquo in Proceed-ings of the Pacific Basin Conference on Hazardous Waste p 5701998
[13] D A Cremers and L J Radziemski Handbook of BreakdownSpectroscopy John Wiley amp Sons 2006
[14] J P Singh and S N Thakur Eds Laser-Induced BreakdownSpectroscopy Elsevier BV 2007
[15] N K Rai and A K Rai ldquoLIBS-An efficient approach for thedetermination of Cr in industrial wastewaterrdquo Journal of Haz-ardous Materials vol 150 no 3 pp 835ndash838 2008
6 Journal of Chemistry
[16] N K Rai A K Rai A Kumar and S N Thakur ldquoDetectionsensitivity of laser-induced breakdown spectroscopy for Cr IIin liquid samplesrdquo Applied Optics vol 47 no 31 pp G105ndashG1112008
[17] A Kramida Y Ralchenko J Reader et al ldquoNIST atomic spec-tra database (ver 50)rdquo 2012 httpphysicsnistgovPhysRef-DataASD
[18] A Elhassan G Cristoforetti and S Legnaioli ldquoLIBS calibrationcurves and determination of limits of detection (LOD) in singleand double pulse configuration for quantitative LIBS analysisof bronzesrdquo in Proceedings of the International Conference inConservation Strategies for Saving Indoor Metallic Collectionspp 72ndash77 2007
[19] SMA Rahim SHasnain and J Farkhanda ldquoEffect of calciummagnesium sodium and potassium on farm plantations of var-ious agroeclogical zones of Punjab PakistanrdquoAfrican Journal ofPlant Science vol 5 no 5 pp 450ndash459 2011
Submit your manuscripts athttpwwwhindawicom
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom
International Journal of
Analytical ChemistryVolume 2013
ISRN Chromatography
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2013
The Scientific World Journal
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
CatalystsJournal of
ISRN Analytical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Advances in
Physical Chemistry
ISRN Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
ISRN Inorganic Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2013
ISRN Organic Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Journal of
Spectroscopy
Journal of Chemistry 3
Figure 2 Sampling area near Kasur district of Punjab Pakistan
3 Results and Discussion
31 Calibration Curve Instrumental calibration is an essen-tial stage for quantitative analysis It gives the relationshipbetween response of the instrument (integrated intensityin arb units) and analyte concentration (in mg kgminus1) Weuse five indigenously prepared standard samples by mixingwell grinded and sieved known ratio of potassium chro-mate (K
2CrO4gt 99 pure and 19419 molecular weight
supplied by Santa Cruz Biotechnology Inc) and standardsoil (chromium-free soil) obtained from Institute of Soil andEnvironmental Sciences University of Agriculture Faisal-abad The standard soil was also confirmed by inductivelycoupled plasma-optical emission spectroscopy (ICP-OES) forabsence of chromium We started with mixing of 1865 g(measured by scalemodel ATY224 from ShimadzuCorpora-tion having readability of 01mg) of K
2CrO4in 1000 g of clean
soil to get standard sample containing Cr 500mg kgminus1 Thewhole sample was mixed thoroughly until a homogenizedsample was obtained then 100 g of sample was taken outof the homogenized sample for analysis After that 1685 gof powdered salt was added more to the remaining mixedsample to get standard containing Cr 1000mg kgminus1 In thisway we prepared five standard samples each of 100 g Threerepresentative pellets from each sample were made to getaverage of spectra (chromium line 42748 nm) for eachstandard sample Calibration curve (shown in Figure 3) wasconstructed between Cr concentration and integrated inten-sity of the signal for 42748 nm avoiding self-absorption andbroadening effects whichmay rise in case of considering peakintensity for quantitative analysis The linear regression coef-ficient also called coefficient of determination 1198772 = 09789showed the good linear relationship between concentrationand integrated intensity
The analysis of variance (ANOVA) table was constructedfor this linear regression model given in Table 1 to furthercheck the statistical dependence of concentration of analyteon integrated intensity
The small 119875-value in the ANOVA table shows that resultshave not happened by chance but 119910 (integrated intensity)
Table 1 ANOVA table for Cr calibration curve
Item Degrees offreedom
Sum ofsquares
Meansquare 119865 statistic 119875 value
Model 1 556960 556960 18679068 84 times 10minus4
Error 3 89452 298173333Total 4 5659052
R2= 09789
1400
1200
1000
800
600
400
200
00 500 1000 1500 2000 2500
Cr concentration (mgkg)
Inte
grat
ed in
tens
ity (a
u)
Y = 814 + 0472 lowast X
Figure 3 Calibration curve for Cr in soil
and 119909 (analyte concentration) parameters are strongly inter-related
The limit of detection [18] for Cr was found by using thefollowing
LOD =3radic1198782
+ 1198782
119886
+ (119886119887)2
lowast 1198782
119887
119887
(1)
where 119878 is the standard deviation of calibration data 119886is the intercept of the calibration curve at zero analyteconcentration 119878
119886is the error in the intercept and 119878
119887is
the indetermination on the slope of the calibration curveThe value of LOD was found 2371mg kgminus1 well below thedetected values in the region
The LIBS spectrum of chromium-free soil sample isshown in Figure 4(a) In Figure 4(b) emission lines ofiron (35465 nm) chromium (42748 nm) phosphorus(519141 nm) sodium (58897 nm) chlorine (49957 nm) andso forth were identified in the spectrum Chromium (Cr) isfound in tanning industry effluents due to the use of chromealum and chromium(III) sulphate in chrome tanning ofleather Due to its solubility it is mixed with waste water andis flushed out mostly without any effort of chrome recovery
The concentration of the Cr in the soil samples wascalculated in the area using calibration curve and it wasfound that the concentration of Cr varies randomly fromthe minimum value of 128mg kgminus1 to the maximum value of1829mg kgminus1 with mean value of 468mg kgminus1 The range ofconcentration is 1701mg kgminus1 and standard deviation in theconcentration in samples is 37144mg kgminus1 The value of
4 Journal of Chemistry
600
300
0300 400 500 600 700
633
57 A
l-II
589
43 Z
n-II
518
36 M
g-I
441
73 T
i-I
392
77 F
e-I
317
93 C
a-II
Wavelength (nm)
Inte
nsity
(au
)
(a)
723
61 (C
-II)
634
75 (S
i-II)
588
99 (N
a-I)
(N-I
I)499
57 (C
l-II)
427
48 (C
r-I)
427
48 (C
r-I)
395
43 (F
e-I)
395
43 (F
e-I)
317
39 519
10 (P
-II)
600
600
900
300
300
390 400 410 420 430
0
0
300 400 500 600 700Wavelength (nm)
Wavelength (nm)
Inte
nsity
(au
)
Inte
nsity
(au
)
(b)
Figure 4 (a) Spectrum of unpolluted soil from soil sciences department (UAF) (b) Spectrum of polluted soil from sampling area
Cr concentration near the effluent drain was found to be839mg kgminus1 maximum but at the location of old stagnantpool concentration of the Cr is very high up to 1829mg kgminus1The random distribution of Cr (shown in Figure 5) in soilin the area is due to unplanned distribution of the tanneriesin the area and due to deteriorating uneven constructionconditions and broken brick lining of the drains and textureof the soil causing seepage of polluted water
The elements which can be detected in the sample alongwith their possible transitions are given in Table 2 Theobserved difference is within the narrow bandwidth of thespectrometer
The elements sodium and chlorine were found in thesoil around the tanneries because sodium chloride (NaCl) isused in large quantity for skin preservation or the picklingprocess of leather Since it is highly soluble and stable soeffluent treatment does not much reduce its concentrationand it remains in the effluent from which it is leached intothe soil to a reasonable distance Increased salt concentrationin the water is becoming a serious issue to the environment
Chlorides have adverse effects to the growth of plantsbacteria and fish in surface water When this saline wateris used for irrigation purpose soil salinity increases and cropyield decreases Calcium level in soil has high concentrationof sodium which may reduce plant growth [19] This type ofsoil is called sodic soil The plants ability of water extractionfrom saline soil is also reduced
4 Conclusion
Laser induced breakdown spectroscopy can be used asqualitative and quantitative analytical technique with verylow limit of detection (in our study it was found to be2371mg kgminus1) The study depicted the high concentration ofCr in the soil which in turn can be uptaken by plants andfood crops in the area and ultimately can be introduced inthe food chain It has been observed that in the presence oforganic acids (citric and oxalic) uptake of Cr may increaseand can be toxic for the community The salinity of the soil isalso increasing due to dissolved salts in the effluents causing
Journal of Chemistry 5
Table 2 Important elements found in different samples with their possible transitions
Element symbol Wavelength (NIST) (nm) Wavelength observed (nm) Difference (nm) ConfigurationFe I 395465 39543 0035 3p64f mdash 3p66fCr I 4626174 46261 00074 3d44s2 mdash 3d4(5D)4s4p(3P∘)Cl II 4995473 49957 00227 3s23p3(2D∘)3d mdash 3s23p3(2D∘)4pP II 519141 51910 0041 3s23p4s mdash 3s23p4pN II 5674 56738 0020 2s22p3p mdash 2s22p3dNa I 5889950943 58897 0025094 2p63s mdash 2p63pSi II 63471 63475 0040 1s22p4p mdash 1s22p4d
Sam
ple n
umbe
r for
each
loca
tion
Distance from the point source
Conc
entra
tion
(ppm
) Clipped gr
aph
for clar
ity in
random va
riatio
n
600
400
2000
50100
150200
2
4
6
Figure 5 Variation of Cr concentration with distance for differentsamples
low yield of crop in those areas The soil remediation processis needed to avoid hazards of heavymetal pollution LIBS canbe used for onlinemonitoring of the waste treatment facilitieseffectively and soil remediation processes due to its rapid andmultielemental analysis capabilities
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgments
The data presented here is part of thesis of first author atGovernment College University Faisalabad (Pakistan) Theauthors are thankful to the Higher Education Commis-sion (HEC) Pakistan for providing scholarship for PhDin Environmental Science The authors are also thankfulto the Institute of Soil and Environmental Sciences Uni-versity of Agriculture Faisalabad for providing standardsoil samples This research was partially supported by theCOMSTECH-TWAS Joint Research Grant Program (Grantno 09-255RGEASAS C UNESCO FR 3240231220)
References
[1] A A Belay ldquoImpacts of chromium from tannery effluent andevaluation of alternative treatment optionsrdquo Journal of Environ-mental Protection vol 1 pp 53ndash58 2010
[2] S Mubin S Gul M I A Khokhar and M Ashraf ldquoStatisticalsolution for the industrial waste problemrdquo Journal of Drainageand Water Management vol 6 no 2 pp 55ndash68 2002
[3] M A Khan A Wajid S Noor F K Khattak S Akhter and IU Rahman ldquoEffect of soil contamination on some heavymetalscontent of Cannabis sativardquo Journal of the Chemical Society ofPakistan vol 30 no 6 pp 805ndash809 2008
[4] K Rehman S Ashraf U Rashid et al ldquoComparison of proxi-mate and heavy metal contents of vegetables grown with freshand wastewaterrdquo Pakistan Journal of Botany vol 45 no 2 pp391ndash400 2013
[5] E T Oppelt In Situ Treatment of Soil and Groundwater Con-taminated with Chromium Technical Resource Guide 2000
[6] Z Krejpcio ldquoEssentiality of chromium for human nutrition andhealthrdquoPolish Journal of Environmental Studies vol 10 no 6 pp399ndash404 2001
[7] R Eisler ldquoChromium hazards to fish wildlife and invertebratesa synoptic Reviewrdquo Biological Report US Fish amp Wildlife Ser-vice Laurel Md USA 1986
[8] OSHA-Occupational Safety and Health Administration SmallEntity Compliance Guide for the Hexavalent Chromium Stan-dards US Department of Labour 2006
[9] J Wyszkowska ldquoSoil contamination by chromium and its enzy-matic activity and yieldingrdquo Polish Journal of EnvironmentalStudies vol 11 no 1 pp 79ndash84 2002
[10] A Malek M Hachemi and V Didier ldquoNew approach of depol-lution of solid chromium leather waste by the use of organicchelates Economical and environmental impactsrdquo Journal ofHazardous Materials vol 170 no 1 pp 156ndash162 2009
[11] M Irfan M Ibrahim U Rashid M Nisa and A Al-MuhtasebldquoOptimization of Cr(III) removal from wastewater using Thes-pesia populenea particles by response surface methodologyrdquoAsian Journal of Chemistry vol 25 no 15 2013
[12] M A Khwaja S Nasreen and M R Jan ldquoStatus and problemsof hazardous effluents from tanneries in NWFPrdquo in Proceed-ings of the Pacific Basin Conference on Hazardous Waste p 5701998
[13] D A Cremers and L J Radziemski Handbook of BreakdownSpectroscopy John Wiley amp Sons 2006
[14] J P Singh and S N Thakur Eds Laser-Induced BreakdownSpectroscopy Elsevier BV 2007
[15] N K Rai and A K Rai ldquoLIBS-An efficient approach for thedetermination of Cr in industrial wastewaterrdquo Journal of Haz-ardous Materials vol 150 no 3 pp 835ndash838 2008
6 Journal of Chemistry
[16] N K Rai A K Rai A Kumar and S N Thakur ldquoDetectionsensitivity of laser-induced breakdown spectroscopy for Cr IIin liquid samplesrdquo Applied Optics vol 47 no 31 pp G105ndashG1112008
[17] A Kramida Y Ralchenko J Reader et al ldquoNIST atomic spec-tra database (ver 50)rdquo 2012 httpphysicsnistgovPhysRef-DataASD
[18] A Elhassan G Cristoforetti and S Legnaioli ldquoLIBS calibrationcurves and determination of limits of detection (LOD) in singleand double pulse configuration for quantitative LIBS analysisof bronzesrdquo in Proceedings of the International Conference inConservation Strategies for Saving Indoor Metallic Collectionspp 72ndash77 2007
[19] SMA Rahim SHasnain and J Farkhanda ldquoEffect of calciummagnesium sodium and potassium on farm plantations of var-ious agroeclogical zones of Punjab PakistanrdquoAfrican Journal ofPlant Science vol 5 no 5 pp 450ndash459 2011
Submit your manuscripts athttpwwwhindawicom
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom
International Journal of
Analytical ChemistryVolume 2013
ISRN Chromatography
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2013
The Scientific World Journal
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
CatalystsJournal of
ISRN Analytical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Advances in
Physical Chemistry
ISRN Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
ISRN Inorganic Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2013
ISRN Organic Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Journal of
Spectroscopy
4 Journal of Chemistry
600
300
0300 400 500 600 700
633
57 A
l-II
589
43 Z
n-II
518
36 M
g-I
441
73 T
i-I
392
77 F
e-I
317
93 C
a-II
Wavelength (nm)
Inte
nsity
(au
)
(a)
723
61 (C
-II)
634
75 (S
i-II)
588
99 (N
a-I)
(N-I
I)499
57 (C
l-II)
427
48 (C
r-I)
427
48 (C
r-I)
395
43 (F
e-I)
395
43 (F
e-I)
317
39 519
10 (P
-II)
600
600
900
300
300
390 400 410 420 430
0
0
300 400 500 600 700Wavelength (nm)
Wavelength (nm)
Inte
nsity
(au
)
Inte
nsity
(au
)
(b)
Figure 4 (a) Spectrum of unpolluted soil from soil sciences department (UAF) (b) Spectrum of polluted soil from sampling area
Cr concentration near the effluent drain was found to be839mg kgminus1 maximum but at the location of old stagnantpool concentration of the Cr is very high up to 1829mg kgminus1The random distribution of Cr (shown in Figure 5) in soilin the area is due to unplanned distribution of the tanneriesin the area and due to deteriorating uneven constructionconditions and broken brick lining of the drains and textureof the soil causing seepage of polluted water
The elements which can be detected in the sample alongwith their possible transitions are given in Table 2 Theobserved difference is within the narrow bandwidth of thespectrometer
The elements sodium and chlorine were found in thesoil around the tanneries because sodium chloride (NaCl) isused in large quantity for skin preservation or the picklingprocess of leather Since it is highly soluble and stable soeffluent treatment does not much reduce its concentrationand it remains in the effluent from which it is leached intothe soil to a reasonable distance Increased salt concentrationin the water is becoming a serious issue to the environment
Chlorides have adverse effects to the growth of plantsbacteria and fish in surface water When this saline wateris used for irrigation purpose soil salinity increases and cropyield decreases Calcium level in soil has high concentrationof sodium which may reduce plant growth [19] This type ofsoil is called sodic soil The plants ability of water extractionfrom saline soil is also reduced
4 Conclusion
Laser induced breakdown spectroscopy can be used asqualitative and quantitative analytical technique with verylow limit of detection (in our study it was found to be2371mg kgminus1) The study depicted the high concentration ofCr in the soil which in turn can be uptaken by plants andfood crops in the area and ultimately can be introduced inthe food chain It has been observed that in the presence oforganic acids (citric and oxalic) uptake of Cr may increaseand can be toxic for the community The salinity of the soil isalso increasing due to dissolved salts in the effluents causing
Journal of Chemistry 5
Table 2 Important elements found in different samples with their possible transitions
Element symbol Wavelength (NIST) (nm) Wavelength observed (nm) Difference (nm) ConfigurationFe I 395465 39543 0035 3p64f mdash 3p66fCr I 4626174 46261 00074 3d44s2 mdash 3d4(5D)4s4p(3P∘)Cl II 4995473 49957 00227 3s23p3(2D∘)3d mdash 3s23p3(2D∘)4pP II 519141 51910 0041 3s23p4s mdash 3s23p4pN II 5674 56738 0020 2s22p3p mdash 2s22p3dNa I 5889950943 58897 0025094 2p63s mdash 2p63pSi II 63471 63475 0040 1s22p4p mdash 1s22p4d
Sam
ple n
umbe
r for
each
loca
tion
Distance from the point source
Conc
entra
tion
(ppm
) Clipped gr
aph
for clar
ity in
random va
riatio
n
600
400
2000
50100
150200
2
4
6
Figure 5 Variation of Cr concentration with distance for differentsamples
low yield of crop in those areas The soil remediation processis needed to avoid hazards of heavymetal pollution LIBS canbe used for onlinemonitoring of the waste treatment facilitieseffectively and soil remediation processes due to its rapid andmultielemental analysis capabilities
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgments
The data presented here is part of thesis of first author atGovernment College University Faisalabad (Pakistan) Theauthors are thankful to the Higher Education Commis-sion (HEC) Pakistan for providing scholarship for PhDin Environmental Science The authors are also thankfulto the Institute of Soil and Environmental Sciences Uni-versity of Agriculture Faisalabad for providing standardsoil samples This research was partially supported by theCOMSTECH-TWAS Joint Research Grant Program (Grantno 09-255RGEASAS C UNESCO FR 3240231220)
References
[1] A A Belay ldquoImpacts of chromium from tannery effluent andevaluation of alternative treatment optionsrdquo Journal of Environ-mental Protection vol 1 pp 53ndash58 2010
[2] S Mubin S Gul M I A Khokhar and M Ashraf ldquoStatisticalsolution for the industrial waste problemrdquo Journal of Drainageand Water Management vol 6 no 2 pp 55ndash68 2002
[3] M A Khan A Wajid S Noor F K Khattak S Akhter and IU Rahman ldquoEffect of soil contamination on some heavymetalscontent of Cannabis sativardquo Journal of the Chemical Society ofPakistan vol 30 no 6 pp 805ndash809 2008
[4] K Rehman S Ashraf U Rashid et al ldquoComparison of proxi-mate and heavy metal contents of vegetables grown with freshand wastewaterrdquo Pakistan Journal of Botany vol 45 no 2 pp391ndash400 2013
[5] E T Oppelt In Situ Treatment of Soil and Groundwater Con-taminated with Chromium Technical Resource Guide 2000
[6] Z Krejpcio ldquoEssentiality of chromium for human nutrition andhealthrdquoPolish Journal of Environmental Studies vol 10 no 6 pp399ndash404 2001
[7] R Eisler ldquoChromium hazards to fish wildlife and invertebratesa synoptic Reviewrdquo Biological Report US Fish amp Wildlife Ser-vice Laurel Md USA 1986
[8] OSHA-Occupational Safety and Health Administration SmallEntity Compliance Guide for the Hexavalent Chromium Stan-dards US Department of Labour 2006
[9] J Wyszkowska ldquoSoil contamination by chromium and its enzy-matic activity and yieldingrdquo Polish Journal of EnvironmentalStudies vol 11 no 1 pp 79ndash84 2002
[10] A Malek M Hachemi and V Didier ldquoNew approach of depol-lution of solid chromium leather waste by the use of organicchelates Economical and environmental impactsrdquo Journal ofHazardous Materials vol 170 no 1 pp 156ndash162 2009
[11] M Irfan M Ibrahim U Rashid M Nisa and A Al-MuhtasebldquoOptimization of Cr(III) removal from wastewater using Thes-pesia populenea particles by response surface methodologyrdquoAsian Journal of Chemistry vol 25 no 15 2013
[12] M A Khwaja S Nasreen and M R Jan ldquoStatus and problemsof hazardous effluents from tanneries in NWFPrdquo in Proceed-ings of the Pacific Basin Conference on Hazardous Waste p 5701998
[13] D A Cremers and L J Radziemski Handbook of BreakdownSpectroscopy John Wiley amp Sons 2006
[14] J P Singh and S N Thakur Eds Laser-Induced BreakdownSpectroscopy Elsevier BV 2007
[15] N K Rai and A K Rai ldquoLIBS-An efficient approach for thedetermination of Cr in industrial wastewaterrdquo Journal of Haz-ardous Materials vol 150 no 3 pp 835ndash838 2008
6 Journal of Chemistry
[16] N K Rai A K Rai A Kumar and S N Thakur ldquoDetectionsensitivity of laser-induced breakdown spectroscopy for Cr IIin liquid samplesrdquo Applied Optics vol 47 no 31 pp G105ndashG1112008
[17] A Kramida Y Ralchenko J Reader et al ldquoNIST atomic spec-tra database (ver 50)rdquo 2012 httpphysicsnistgovPhysRef-DataASD
[18] A Elhassan G Cristoforetti and S Legnaioli ldquoLIBS calibrationcurves and determination of limits of detection (LOD) in singleand double pulse configuration for quantitative LIBS analysisof bronzesrdquo in Proceedings of the International Conference inConservation Strategies for Saving Indoor Metallic Collectionspp 72ndash77 2007
[19] SMA Rahim SHasnain and J Farkhanda ldquoEffect of calciummagnesium sodium and potassium on farm plantations of var-ious agroeclogical zones of Punjab PakistanrdquoAfrican Journal ofPlant Science vol 5 no 5 pp 450ndash459 2011
Submit your manuscripts athttpwwwhindawicom
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom
International Journal of
Analytical ChemistryVolume 2013
ISRN Chromatography
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2013
The Scientific World Journal
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
CatalystsJournal of
ISRN Analytical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Advances in
Physical Chemistry
ISRN Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
ISRN Inorganic Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2013
ISRN Organic Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Journal of
Spectroscopy
Journal of Chemistry 5
Table 2 Important elements found in different samples with their possible transitions
Element symbol Wavelength (NIST) (nm) Wavelength observed (nm) Difference (nm) ConfigurationFe I 395465 39543 0035 3p64f mdash 3p66fCr I 4626174 46261 00074 3d44s2 mdash 3d4(5D)4s4p(3P∘)Cl II 4995473 49957 00227 3s23p3(2D∘)3d mdash 3s23p3(2D∘)4pP II 519141 51910 0041 3s23p4s mdash 3s23p4pN II 5674 56738 0020 2s22p3p mdash 2s22p3dNa I 5889950943 58897 0025094 2p63s mdash 2p63pSi II 63471 63475 0040 1s22p4p mdash 1s22p4d
Sam
ple n
umbe
r for
each
loca
tion
Distance from the point source
Conc
entra
tion
(ppm
) Clipped gr
aph
for clar
ity in
random va
riatio
n
600
400
2000
50100
150200
2
4
6
Figure 5 Variation of Cr concentration with distance for differentsamples
low yield of crop in those areas The soil remediation processis needed to avoid hazards of heavymetal pollution LIBS canbe used for onlinemonitoring of the waste treatment facilitieseffectively and soil remediation processes due to its rapid andmultielemental analysis capabilities
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgments
The data presented here is part of thesis of first author atGovernment College University Faisalabad (Pakistan) Theauthors are thankful to the Higher Education Commis-sion (HEC) Pakistan for providing scholarship for PhDin Environmental Science The authors are also thankfulto the Institute of Soil and Environmental Sciences Uni-versity of Agriculture Faisalabad for providing standardsoil samples This research was partially supported by theCOMSTECH-TWAS Joint Research Grant Program (Grantno 09-255RGEASAS C UNESCO FR 3240231220)
References
[1] A A Belay ldquoImpacts of chromium from tannery effluent andevaluation of alternative treatment optionsrdquo Journal of Environ-mental Protection vol 1 pp 53ndash58 2010
[2] S Mubin S Gul M I A Khokhar and M Ashraf ldquoStatisticalsolution for the industrial waste problemrdquo Journal of Drainageand Water Management vol 6 no 2 pp 55ndash68 2002
[3] M A Khan A Wajid S Noor F K Khattak S Akhter and IU Rahman ldquoEffect of soil contamination on some heavymetalscontent of Cannabis sativardquo Journal of the Chemical Society ofPakistan vol 30 no 6 pp 805ndash809 2008
[4] K Rehman S Ashraf U Rashid et al ldquoComparison of proxi-mate and heavy metal contents of vegetables grown with freshand wastewaterrdquo Pakistan Journal of Botany vol 45 no 2 pp391ndash400 2013
[5] E T Oppelt In Situ Treatment of Soil and Groundwater Con-taminated with Chromium Technical Resource Guide 2000
[6] Z Krejpcio ldquoEssentiality of chromium for human nutrition andhealthrdquoPolish Journal of Environmental Studies vol 10 no 6 pp399ndash404 2001
[7] R Eisler ldquoChromium hazards to fish wildlife and invertebratesa synoptic Reviewrdquo Biological Report US Fish amp Wildlife Ser-vice Laurel Md USA 1986
[8] OSHA-Occupational Safety and Health Administration SmallEntity Compliance Guide for the Hexavalent Chromium Stan-dards US Department of Labour 2006
[9] J Wyszkowska ldquoSoil contamination by chromium and its enzy-matic activity and yieldingrdquo Polish Journal of EnvironmentalStudies vol 11 no 1 pp 79ndash84 2002
[10] A Malek M Hachemi and V Didier ldquoNew approach of depol-lution of solid chromium leather waste by the use of organicchelates Economical and environmental impactsrdquo Journal ofHazardous Materials vol 170 no 1 pp 156ndash162 2009
[11] M Irfan M Ibrahim U Rashid M Nisa and A Al-MuhtasebldquoOptimization of Cr(III) removal from wastewater using Thes-pesia populenea particles by response surface methodologyrdquoAsian Journal of Chemistry vol 25 no 15 2013
[12] M A Khwaja S Nasreen and M R Jan ldquoStatus and problemsof hazardous effluents from tanneries in NWFPrdquo in Proceed-ings of the Pacific Basin Conference on Hazardous Waste p 5701998
[13] D A Cremers and L J Radziemski Handbook of BreakdownSpectroscopy John Wiley amp Sons 2006
[14] J P Singh and S N Thakur Eds Laser-Induced BreakdownSpectroscopy Elsevier BV 2007
[15] N K Rai and A K Rai ldquoLIBS-An efficient approach for thedetermination of Cr in industrial wastewaterrdquo Journal of Haz-ardous Materials vol 150 no 3 pp 835ndash838 2008
6 Journal of Chemistry
[16] N K Rai A K Rai A Kumar and S N Thakur ldquoDetectionsensitivity of laser-induced breakdown spectroscopy for Cr IIin liquid samplesrdquo Applied Optics vol 47 no 31 pp G105ndashG1112008
[17] A Kramida Y Ralchenko J Reader et al ldquoNIST atomic spec-tra database (ver 50)rdquo 2012 httpphysicsnistgovPhysRef-DataASD
[18] A Elhassan G Cristoforetti and S Legnaioli ldquoLIBS calibrationcurves and determination of limits of detection (LOD) in singleand double pulse configuration for quantitative LIBS analysisof bronzesrdquo in Proceedings of the International Conference inConservation Strategies for Saving Indoor Metallic Collectionspp 72ndash77 2007
[19] SMA Rahim SHasnain and J Farkhanda ldquoEffect of calciummagnesium sodium and potassium on farm plantations of var-ious agroeclogical zones of Punjab PakistanrdquoAfrican Journal ofPlant Science vol 5 no 5 pp 450ndash459 2011
Submit your manuscripts athttpwwwhindawicom
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom
International Journal of
Analytical ChemistryVolume 2013
ISRN Chromatography
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2013
The Scientific World Journal
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
CatalystsJournal of
ISRN Analytical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Advances in
Physical Chemistry
ISRN Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
ISRN Inorganic Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2013
ISRN Organic Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Journal of
Spectroscopy
6 Journal of Chemistry
[16] N K Rai A K Rai A Kumar and S N Thakur ldquoDetectionsensitivity of laser-induced breakdown spectroscopy for Cr IIin liquid samplesrdquo Applied Optics vol 47 no 31 pp G105ndashG1112008
[17] A Kramida Y Ralchenko J Reader et al ldquoNIST atomic spec-tra database (ver 50)rdquo 2012 httpphysicsnistgovPhysRef-DataASD
[18] A Elhassan G Cristoforetti and S Legnaioli ldquoLIBS calibrationcurves and determination of limits of detection (LOD) in singleand double pulse configuration for quantitative LIBS analysisof bronzesrdquo in Proceedings of the International Conference inConservation Strategies for Saving Indoor Metallic Collectionspp 72ndash77 2007
[19] SMA Rahim SHasnain and J Farkhanda ldquoEffect of calciummagnesium sodium and potassium on farm plantations of var-ious agroeclogical zones of Punjab PakistanrdquoAfrican Journal ofPlant Science vol 5 no 5 pp 450ndash459 2011
Submit your manuscripts athttpwwwhindawicom
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom
International Journal of
Analytical ChemistryVolume 2013
ISRN Chromatography
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2013
The Scientific World Journal
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
CatalystsJournal of
ISRN Analytical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Advances in
Physical Chemistry
ISRN Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
ISRN Inorganic Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2013
ISRN Organic Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Journal of
Spectroscopy
Submit your manuscripts athttpwwwhindawicom
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom
International Journal of
Analytical ChemistryVolume 2013
ISRN Chromatography
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2013
The Scientific World Journal
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
CatalystsJournal of
ISRN Analytical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Advances in
Physical Chemistry
ISRN Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
ISRN Inorganic Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2013
ISRN Organic Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013
Journal of
Spectroscopy