Determination of the residues of eleven organophosphorus insecticides in Job's-tears by gas chromatography with a nitrogen-phosphorus detector.
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 x 10(-10) to 5.0 x 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.
Wu
Jialun
J
Zhejiang University, Institute of Pesticide and Environmental Toxicology, Huajiachi Campus, Hangzhou, Zhejiang, People's Republic of China. jlwu@zju.edu.cn
Li
Liqing
L
D002849:Chromatography, Gas; D031742:Coix / Q000737:chemistry*; D009584:Nitrogen / Q000032:analysis; D009943:Organophosphorus Compounds / Q000032:analysis*; D010573:Pesticide Residues / Q000032:analysis*; D010758:Phosphorus / Q000032:analysis
D009943:Organophosphorus Compounds; D010573:Pesticide Residues; D010758:Phosphorus; D009584:Nitrogen