Analysis of the Residues of 20 Organochlorine Pesticides in Herba epimedii, a Chinese Herbal Medicine, by Solid-Phase Extraction with Gas Chromatography/Negative Chemical Ionization–Mass Spectrometry

Abstract

Abstract A multiresidue analytical method has been developed to simultaneously determine the residues of 20 organochlorine pesticides in Herba epimedii, a traditional Chinese medicine. The 20 pesticides are included in the list of regulated substances by the Food and Environmental Hygiene Department in Hong Kong. The method consists of solid-phase extraction for cleanup of samples and GC coupled on-line with negative chemical ion-MS to analyze the target pesticides. The chromatographic separation of the compounds was carried out on a DB-1701 column by using an optimal temperature program, and the quantitative analysis was conducted by selected ion monitoring. The LOD and LOQ values fell in the range of 0.05555.8821 and 0.124117.9333 ng/g, respectively. The average recoveries were between 75.4 and 90.7 (n = 5) for the 20 organochlorine pesticides. The developed method proved to be reliable and accurate, and permits rapid determination of the 20 organochlorine pesticides in one run.