Response to Letter to the Editor regarding “Determination of glyphosate in groundwater samples...
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LETTER TO THE EDITOR Response to Letter to the Editor regarding “Determination of glyphosate in groundwater samples using an ultrasensitive immunoassay and confirmation by on-line solid phase extraction followed by liquid chromatography coupled to tandem mass spectrometry” Josep Sanchís & Lina Kantiani & Marta Llorca & Fernando Rubio & Antoni Ginebreda & Josep Fraile & Teresa Garrido & Marinella Farré Published online: 11 May 2012 # Springer-Verlag 2012 Dear Sir, As was clearly stated in our article [1], its main objectives were: 1. to assess the performance of a current immunoassay- based method for rapid monitoring of glyphosate in water; and 2. to develop an on-line SPE–LC–MS–MS method for confirmation and quantification of glyphosate in water. As part of the second objective, it was considered worth- while testing the applicability of both methods on real environmental water samples, particularly groundwater. In this context, it seems the correspondents’ question in their Letter to the Editor [2] was whether or not they were “true” groundwater samples. On this issue, the following com- ments can be made: 1. The water samples analyzed were mostly obtained in areas where there is intense agricultural activity in which contamination of groundwater by nitrates and pesticides are known problems [3, 4]. For this reason, the places sampled were believed to be susceptible to the eventual presence of glyphosate. 2. The aquifers sampled were, with few exceptions, mainly unconfined porous aquifers of sandy and gravel compo- sition. It is clear that the presence of pesticides and nitrates in groundwater is associated with well known recharge processes and is affected by surface waters. This does not, however, prevent these samples qualify- ing as “groundwater”, because they came from the saturated zone of these aquifers. 3. All the sampling sites referred to are wells that belong to the “operational monitoring network” for pesticide con- trol in groundwater and are thus regularly surveyed by the responsible water authority (Catalan Water Agency, ACA) as part of the monitoring required by application of the Water Framework Directive to set the “quality status” of groundwater. 4. The objective of the article was not to focus on regula- tory aspects; rather, the key point to keep in mind is that the analytical method was proved to perform correctly for real water samples, irrespective of whether or not they are ground or surface water. This article is in response to the ‘Letter to the Editor’ to be found at http://dx.doi.org/10.1007/s00216-012-6046-z. J. Sanchís : L. Kantiani : M. Llorca : A. Ginebreda : M. Farré (*) Institute of Environmental Assessment and Water Research (IDAEA-CSIC), C/Jordi Girona, 18-26, 08034 Barcelona, Spain e-mail: [email protected] F. Rubio Abraxis LLC, 54 Steam Whistle Drive, Warminster, PA 18974, USA J. Fraile : T. Garrido Catalan Water Agency, Provença 204-208, 08036 Barcelona, Spain Anal Bioanal Chem (2012) 404:615–616 DOI 10.1007/s00216-012-6048-x
Transcript of Response to Letter to the Editor regarding “Determination of glyphosate in groundwater samples...
LETTER TO THE EDITOR
Response to Letter to the Editor regarding “Determinationof glyphosate in groundwater samples using an ultrasensitiveimmunoassay and confirmation by on-line solid phase extractionfollowed by liquid chromatography coupled to tandem massspectrometry”
Josep Sanchís & Lina Kantiani & Marta Llorca &
Fernando Rubio & Antoni Ginebreda & Josep Fraile &
Teresa Garrido & Marinella Farré
Published online: 11 May 2012# Springer-Verlag 2012
Dear Sir,As was clearly stated in our article [1], its main objectiveswere:
1. to assess the performance of a current immunoassay-based method for rapid monitoring of glyphosate inwater; and
2. to develop an on-line SPE–LC–MS–MS method forconfirmation and quantification of glyphosate in water.
As part of the second objective, it was considered worth-while testing the applicability of both methods on realenvironmental water samples, particularly groundwater. Inthis context, it seems the correspondents’ question in their
Letter to the Editor [2] was whether or not they were “true”groundwater samples. On this issue, the following com-ments can be made:
1. The water samples analyzed were mostly obtained inareas where there is intense agricultural activity inwhich contamination of groundwater by nitrates andpesticides are known problems [3, 4]. For this reason,the places sampled were believed to be susceptible tothe eventual presence of glyphosate.
2. The aquifers sampled were, with few exceptions, mainlyunconfined porous aquifers of sandy and gravel compo-sition. It is clear that the presence of pesticides andnitrates in groundwater is associated with well knownrecharge processes and is affected by surface waters.This does not, however, prevent these samples qualify-ing as “groundwater”, because they came from thesaturated zone of these aquifers.
3. All the sampling sites referred to are wells that belong tothe “operational monitoring network” for pesticide con-trol in groundwater and are thus regularly surveyed bythe responsible water authority (Catalan Water Agency,ACA) as part of the monitoring required by applicationof the Water Framework Directive to set the “qualitystatus” of groundwater.
4. The objective of the article was not to focus on regula-tory aspects; rather, the key point to keep in mind is thatthe analytical method was proved to perform correctlyfor real water samples, irrespective of whether or notthey are ground or surface water.
This article is in response to the ‘Letter to the Editor’ to be found athttp://dx.doi.org/10.1007/s00216-012-6046-z.
J. Sanchís : L. Kantiani :M. Llorca :A. Ginebreda :M. Farré (*)Institute of Environmental Assessment and Water Research(IDAEA-CSIC),C/Jordi Girona, 18-26,08034 Barcelona, Spaine-mail: [email protected]
F. RubioAbraxis LLC,54 Steam Whistle Drive,Warminster, PA 18974, USA
J. Fraile : T. GarridoCatalan Water Agency,Provença 204-208,08036 Barcelona, Spain
Anal Bioanal Chem (2012) 404:615–616DOI 10.1007/s00216-012-6048-x
References
1. Sanchís J, Kantiani L, Llorca M, Rubio F, Ginebreda F, Fraile J,Garrido T, Farré M (2012) Determination of glyphosate ingroundwater samples using an ultrasensitive immunoassay andconfirmation by on-line solid-phase extraction followed by liq-uid chromatography coupled to tandem mass spectrometry. AnalBioanal Chem 402:2335–2345
2. Reding MA (2012) Letter to the Editor regarding “Determination ofglyphosate in groundwater samples using an ultrasensitive immuno-assay and confirmation by on-line solid-phase extraction followed by
liquid chromatography coupled to tandem mass spectrometry”. AnalBioanal Chem. doi:10.1007/s00216-012-6046-z
3. Postigo CC, López de Alda MJ, Barceló D, Ginebreda A, Garrido T,Fraile J (2010) Analysis and occurrence of selected medium tohighly polar pesticides in groundwater of Catalonia (NE Spain):An approach based on on-line solid phase extraction–liquid chro-matography–electrospray-tandem mass spectrometry detection. JHydrol 383:83–92
4. Garrido T, Fraile J, Niñerola JM, Figueras M, Ginebreda A,Olivella L (2000) Survey of ground water pesticide pollution inthe rural areas of Catalonia (Spain). Int J Environ Chem 78(1):51–65
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