A simplified method for determining 11 organophosphorus insecticides (dichlorvos, methamidophos, acephate, diazinon, dimethoate, chlorpyrifos, malathion, parathion, quinalphos, methidathion, and ethion) in the Chinese herbal medicine Job's-tears is described. Standards were fortified
into Job's-tears (5 g) at 4 levels. The organophosphorus insecticides were extracted with dichloromethane and cleaned up with a mixture of Celite 545–activated carbon (4 + 1). The extracts were analyzed by gas chromatography using a nitrogen-phosphorus detector. Analysis of fortified
Job's-tears shows average recoveries ranged from 73.90–98.70%, 86.31–93.15%, 84.92–96.22%, and 83.29–104.23% at 0.05, 0.1, 0.5, and 1.0 mg/kg levels, respectively. The minimum detectable amount ranged from 1.0 × 10−10 to 5.0 × 10−10
g, and the limit of quantitation for the method was 0.05 mg/kg. The method is rapid, simple, sensitive, reproducible, and applicable to the determination of these 11 organophosphorus insecticides in Job's-tears.
Document Type: Research Article
Zhejiang University, Institute of Pesticide and Environmental Toxicology, Huajiachi Campus, Hangzhou, Zhejiang, People's Republic of China, 310029.
Publication date: September 1, 2004
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