Multi-residue method for fast determination of pesticide residues in plants used in traditional chinese medicine by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry.

An ultra-high-performance liquid chromatographic-tandem mass spectrometry (UHPLC-MS/MS) method for the simultaneous quantification and identification of 116 pesticide residues which were most widely used in plants used in Traditional Chinese Medicine (TCM) in 15 min has been developed and validated. Samples were extracted and cleaned up with modified QuEChERS method and detected by UHPLC-MS/MS under multiple reactions monitoring mode, and quantified by matrix-match calibration. The validation study was carried out on five different matrixes following DG SANCO/2007/3131 of the European Quality Control Guidelines. The linearity of the calibration was good between 5 and 100 ng ml⁻¹ concentration ranges, and the limits of quantification (LOQs) less than 0.01 mg/kg for most pesticides. The mean recoveries of almost all pesticides were in the range from 70% to 120% at three concentration levels ranging from 0.01 mg/kg to 0.1mg/kg with relative standard deviations (RSD) better than 15%. The method was applied on 138 real samples from 102 different kinds of Chinese herbal medicine. 95 positive samples were detected. This method is fast, robust, accurate, selective, sensitive and easy to operate.