Multi-residual Pesticide Monitoring in Commercial Chinese Herbal Medicines by Gas Chromatography-Triple Quadrupole Tandem Mass Spectrometry

To investigate multi-residual pesticide monitoring data in commercial Chinese herbal medicines on major markets, an easy, rapid, and selective gas chromatography with mass spectrometry (GC/MS/MS) method was established for simultaneously determining multi-residual pesticides including organochlorine, pyrethroid, carbamate, and organophosphorus pesticides in Chinese herbal medicines. The analytical method was based on an efficient extraction procedure and further cleanup steps by solid-phase extraction columns, yielding recovery rates in the range of 70.0-120.0 % for the majority of pesticides, except for hexachlorobenze, diazinon, beta-HCH, delta-HCH, and omethoate, with precision values expressed as relative standard deviation of 0.1-14.7 %. The limits of detection of the established GC/MS/MS method for all investigated pesticides ranged from 0.01 to 3.6 mu g kg(-1) and limits of quantification from 0.03 to 11.88 mu g kg(-1). With this validated method, multi-residual pesticides of 132 Chinese herbal medicine samples were analyzed. The monitoring results indicated that pesticide residue was found in 74 samples. In total, 51 pesticides were found with detection rate ranging from 0.76 to 18.94 %. An 82.3 % of positive pesticides were found in less than 6 % of samples. Hexachlorobenzene was found in 25 samples, quintozene in 15 samples, and acephate and simazine in 13 samples. Concentrations of pesticide residue from monitoring data obtained ranged from 0.5 to 203.5 mu g kg(-1). The simple and rapid method can be used as routine analysis method in multi-residual pesticide monitoring of Chinese herbal medicines.