Determination of 70 pesticide residues in Salvia miltiorrhiza from Sichuan by gas chromatography-tandem mass spectrometry

A method was developed for the simultaneous detecting of 70 banned and commonly used pesticide residues in S. miltiorrhiza via gas chromatography-tandem mass spectrometry (GC-MS/MS) by optimizing the sample pretreatment and chromatographic analysis conditions. 44 samples of S. miltiorrhiza from different cities in Sichuan Province were tested by this method. The samples were extracted by aqueous acetonitrile, salted out by QuEChERS extract package (containing anhydrous magnesium sulfate and anhydrous sodium acetate), the extract solution was concentrated and added internal standard triphenyl phosphate, and detected by GC-MS/MS with multiple reaction monitoring (MRM) mode. The results showed that all the 70 pesticides had good linearity within the range of 1-100 μg/L, with the correlation coefficients (r) higher than 0.998 5. More than 87.1% of the tested pesticides had recovery rates between 70% and 120%, and the RSDs were less than 15% at three spiked levels (5×LOD、10×LOD and 20×LOD). The limits of quantitation of this method ranges from 0.01 to 0.03 mg/kg. In 44 batches of samples, 1-5 kinds of pesticides were detected in 22 samples, including dicofol, which was banned by China. This simple, sensitive and accurate method is suitable for the fast screening and detection of pesticide residues in S. miltiorrhiza Bge.. The test results can be applied as a reference for the cultivation and circulation supervision of S. miltiorrhiza from Sichuan Province.