Microwave-Assisted Extraction for the Simultaneous Determination of Thiamethoxam, Imidacloprid, and Carbendazim Residues in Fresh and Cooked Vegetable Samples

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• 作者：Shashi B. Singh ; Gregory D. Foster ; and Shahamat U. Khan
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2004
• 出版时间：January 14, 2004
• 年：2004
• 卷：52
• 期：1
• 页码：105 - 109
• 全文大小：72K
• 年卷期：v.52,no.1(January 14, 2004)
• ISSN：1520-5118

文摘

Microwave-assisted extraction (MAE) was carried out for the simultaneous determination of theinsecticides thiamethoxam [(EZ)-3-(2-chloro-1,3-thiazol-5-ylmethyl)-5-methyl-1,3,5-oxadiazinan-4-ylidene(nitro)amine], imidacloprid [1-(6-chloro-3-pyridylmethyl)-N-nitroimidazolidin-2-ylideneamine], andthe fungicide carbendazim (methyl benzimidazol-2-ylcarbamate) in vegetable samples. Five cropsamples consisting of cabbage, tomatoes, chilies, potatoes, and peppers were fortified with the threepesticides and subjected to MAE followed by cleanup to remove coextractives prior to analysis byhigh-performance liquid chromatography. Using the selected microwave exposure time and powersetting, the recoveries of the three pesticides from the fortified vegetable samples ranged from 68.1to 106%. The corresponding recoveries for samples processed simultaneously but without microwaveexposure ranged from 37.2 to 61.4%. The recoveries by MAE were comparable to those obtained bythe conventional blender extraction technique. The precision of the MAE method was demonstratedby relative standard deviations of <7% for the three pesticides. The cooked cabbage and tomatosamples showed no breakdown of the parent compounds, and the recoveries of three pesticideswere comparable to those obtained with the uncooked samples.Keywords: Microwave-assisted extraction; thiamethoxam; imidacloprid; carbendazim; vegetable crops;multiresidue analysis; cooking; HPLC analysis