Determination of 37 Kinds of Pesticide Residues in Foods with Liquid Chromatography Mass Spectrometry

[Objective] To establish the method of liquid chromatography mass spectrometry(LC-MS) for the determination of pesticide residues in foods.[Methods]The pesticides were extracted with acetonitrile.The extract was salted out and centrifuged,and then it was purified by solid phase extraction column and was eluted with acetonitrile and toluene(3+1).Afterwards,liquid chromatography mass spectrometry(LC-MS) was used to determine pesticide residues ingredients according to the different requirements.[Results]All the 37 kinds of pesticide residues were drained out within 40minutes;the standard linear range was between 0.01-1.0 μg/ml;correlation coefficient r was above 0.99;the labeled recovery rates were between 78%-96%;the relative standard deviations(RSD) was below 10%;the limit of determination(LOD) was 0.001-0.04 mg/kg(S/N=3).[Conclusion]This method is suitable for determining pesticide residues in foods with satisfactory sensitivity,accuracy and precision;it can rapidly detect 37 kinds of pesticide and the concentration level reaches the requirement for detection.