Rapid simultaneous determination of organochlorine and pyrethroid pesticide residues in Lycium barbarum L. using gas chromatography with electron-capture detector

A fast gas chromatographic method for simultaneous determination of 50 organochlorine (OCP) and pyrethroid (PP) pesticides in Lycium barbarum L. is established. OCP and PP were extracted from L. barbarum L. using acetonitrile, cleaned with alumina neutral-florisil column, and eluted by mixed solvents of ethyl acetate and hexane (15 : 85, v/v). Selected pesticides were identified using HP-5 and DB1701 capillary dual column and detected by electron-capture detector. Quantitative analysis was performed using an external standard by HP-5 capillary column. Results show that recoveries were 70.3%–115.7%, and the relative standard deviations (RSDs) were 2.0%–14.4%. The limits of detection of the method were 0.0023–0.0075 mg kg−1, and the limits of quantity were 0.0076–0.0247 mg kg−1. The method can treat multiple samples simultaneously. The results are reproducible and satisfactory.