González-Rodríguez Rosa Ma, Rial-Otero Raquel, Cancho-Grande Beatriz, Simal-Gándara Jesús
Nutrition and Bromatology Group, Analytical and Food Chemistry Department, Faculty of Food Science and Technology, University of Vigo, Ourense Campus, Ourense, Spain.
J Chromatogr A. 2008 Jul 4;1196-1197:100-9. doi: 10.1016/j.chroma.2008.02.087. Epub 2008 Mar 2.
A gas chromatographic method was developed for simultaneously determining residues of 12 insecticides (acrinathrin, bifenthrin, carbofuran, cyfluthrin, lambda-cyhalothrin, cypermethrin, chlorfenvinphos, deltamethrin, esfenvalerate, fenamiphos, methiocarb and tau-fluvalinate) and 11 fungicides (cyprodinil, fludioxonil, iprodione, metalaxyl, penconazole, pyrimethanil, procymidone tebuconazole, triadimefon, triadimenol and vinclozolin) in leafy vegetables. Samples were extracted with acetonitrile and cleaned-up with graphitized carbon black/primary secondary amine (GCB/PSA) solid-phase extraction (SPE) cartridges using acetonitrile:toluene (3:1, v/v) as eluent. The eluate was finally evaporated and redissolved with 0.5 mL of acetone containing the internal standards (pentachlorobenzene and fenpropathrin) and three analyte protectants (3-ethoxy-1,2-propanediol, d-sorbitol and l-gulonic acid gamma-lactone). The addition of analyte protectants allows to avoid the matrix-induced response enhancement effect on quantitation process with absolute recoveries ca. 100%. Precision (expressed as relative standard deviation) was lower than 10% for all pesticides and finally, limits of detection were also 10-20 times lower than maxima residue levels (MRLs) established by European Regulation. The proposed method was applied to determine pesticide residues in commercial leafy vegetables (lettuce, Swiss chard and spinach) purchased from markets in Orense (NW Spain). Pesticide residues were detected in 84% of the total samples (63 from 75 samples) and pesticide concentrations were higher than MRL in 18 samples.
建立了一种气相色谱法，用于同时测定叶菜类蔬菜中12种杀虫剂（氟丙菊酯、联苯菊酯、克百威、氯氟氰菊酯、高效氯氟氰菊酯、氯氰菊酯、毒虫畏、溴氰菊酯、乙氰菊酯、苯线磷、灭多威和氟胺氰菊酯）和11种杀菌剂（嘧菌环胺、咯菌腈、异菌脲、甲霜灵、戊唑醇、嘧霉胺、腐霉利、戊唑醇、三唑酮、三唑醇和乙烯菌核利）的残留量。样品用乙腈提取，并用乙腈∶甲苯（3∶1，v/v）作为洗脱剂，通过石墨化炭黑/伯仲胺（GCB/PSA）固相萃取（SPE）小柱进行净化。最终将洗脱液蒸发，并用含有内标物（五氯苯和甲氰菊酯）以及三种分析物保护剂（3-乙氧基-1,2-丙二醇、d-山梨醇和l-古洛糖酸γ-内酯）的0.5 mL丙酮重新溶解。添加分析物保护剂可避免基质对定量过程的响应增强效应，绝对回收率约为100%。所有农药的精密度（以相对标准偏差表示）均低于10%，最终检测限也比欧洲法规规定的最大残留限量（MRL）低10至20倍。所提出的方法用于测定从西班牙西北部奥伦塞市场购买的市售叶菜类蔬菜（生菜、瑞士甜菜和菠菜）中的农药残留。在总样品（75个样品中的63个）的84%中检测到农药残留，18个样品中的农药浓度高于MRL。
