Journal : Acta Chromatographica
Article : Optimization and validation of a method based on derivatization with methylating agent followed by HPLC-DAD for determining dithiocarbamates residues

Authors :
Patil, A. N.
Pravara Rural College of Pharmacy Department of Pharmacognosy Pravaranagar, Loni 413736 Maharashtra India,
Nirmal, S. A.
Pravara Rural College of Pharmacy Department of Pharmacognosy Pravaranagar, Loni 413736 Maharashtra India, nirmalsunil@rediffmail.com,
Chavan, A. K.
Pravara Rural College of Pharmacy Department of Pharmacognosy Pravaranagar, Loni 413736 Maharashtra India,
Zhou, L.
China Agricultural University Department of Applied Chemistry, College of Science Beijing 100193 China,
Xu, J.
China Agricultural University Department of Applied Chemistry, College of Science Beijing 100193 China,
Luan, L.
China Agricultural University Department of Applied Chemistry, College of Science Beijing 100193 China,
Ma, J.
China Agricultural University Department of Applied Chemistry, College of Science Beijing 100193 China,
Gong, Y.
Ministry of Agriculture Institute for the Control of Agrochemicals Beijing 100026 China,
Qin, D.
Ministry of Agriculture Institute for the Control of Agrochemicals Beijing 100026 China,
Pan, C.
China Agricultural University Department of Applied Chemistry, College of Science Beijing 100193 China,
Abstract : Dithiocarbamates fungicides (DTCs) are worldwidely used fungicides. Residue analytical methods on DTCs are usually based on headspace gas chromatography, which are not much stable and precise. In this study, a specific, simple and reliable method for determining DTCs fungicides residues was optimized and validated. The DTCs in foods and soils were extracted with an alkaline solution of EDTA and L-cysteine, followed by pH adjusting and methyl derivatization in methyl iodine solution. The organic layer of the reactants was separated, concentrated under vacuum and reconstructed in acetonitrile. DTCs residues were eluted on a C18 column and detected by HPLC-DAD at 272 nm. The S-alkyl derivatives of thiram, mancozeb and propineb were separated at different retention times. At fortified levels of 0.05 mg/kg to 2 mg/kg (residue expressed as CS2, in mg/kg, the same below), it is found that recoveries for DTCs spiked in apple, cucumber, tomato, rice and soil samples ranged from 70.8% to 105.3%, with relative standard deviations (RSD) from 0.6% to 13.7%. Limits of detection (LODs) and quantification (LOQs) ranged from 0.003 to 0.026 mg/kg and from 0.011 to 0.105 mg/kg for various foods and soils. This method was also applied to real sample tests.

Keywords : dithiocarbamates, methyl derivatization, pesticide residue, HPLC,
Publishing house : University of Silesia in Katowice
Publication date : 2013
Number : Vol. 25, no. 4
Page : 613 – 625

Bibliography
: 1 European Commission (EC, 2007) http://ec.europa.eu/food/fvo/specialreports/pesticide_residues/annex_2_2005_en.pdf
2 A.K. Malik and W. Faubel, Pestic. Sci., 55, 965 (1999)
3 O.H.J. Szolar, Anal. Chim. Acta, 58, 191 (2007)
4 G. Crnogorac and W. Schwack, Trends Anal. Chem., 28, 40 (2009)
5 G.E. Keppel, J. Assoc. Off Anal. Chem., 52, 162 (1965)
6 M.J.M. Jongen, J.C. Ravensberg and Ravensberg, J. Chromatogr. Sci., 29, 292 (1991)
7 N. Ahmad, L. Guo, P. Mandarakas, V. Frarah, S. Appleby and T. Gibson, J. AOAC Int., 79, 1417 (1996)
8 Z. Vryzas, E.N. Papadakis and E. Papadopoulou-Mourkidou, J. Agric. Food Chem., 50, 2220 (2002)
9 W. Schwack and S. Nyanzi, J. AOAC Int., 78, 458 (1995)
10 M. Häfner, Gesunde Pflanz. 29, 261 (1977)
11 H.P. Their, Lebensmittelchem. Gerichtl. Chem., 31, 25 (1977)
12 R.C. Perz, H. Lishaut and W. Schwack, J. Agric. Food Chem., 48, 792 (2000)
13 Joint FAO/WHO food standard programme codex committee on pesticide residues, 39th Session, Beijing, China, 2007, CX/PR 07/39/6-Add. 1
14 EU Reference Laboratories for Residues of Pesticides, 18.12.2009 (V2) http://www.eurl-pesticides.eu/docs/public/home.asp?LabID=100&Lang=EN
15 Joint FAO/WHO food standard programme codex committee on pesticide residues, 43rd Session Beijing, China, 2011, CX/PR 11/43/3
16 K.H. Gustafsson and R.A. Thompson, J. Agric. Food Chem., 29, 729 (1981)
17 K.H. Gustafsson and C.H. Fahlgren, J. Agric. Food Chem., 31, 461 (1983)
DOI :
Qute : Patil, A. N. ,Nirmal, S. A. ,Chavan, A. K. ,Zhou, L. ,Xu, J. ,Luan, L. ,Ma, J. ,Gong, Y. ,Qin, D. ,Pan, C. ,Pan, C. , Optimization and validation of a method based on derivatization with methylating agent followed by HPLC-DAD for determining dithiocarbamates residues. Acta Chromatographica Vol. 25, no. 4/2013
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