Determination of 33 Kinds of Pesticide Residues in Food by Liquid Chromatography-Mass Spectrometry

[Objective]To establish a method for determination of pesticide residues in foods by liquid chromatography-mass spectrometry(LC-MS). [Methods]The pesticide residues were extracted with acetonitrile homogenate,purified by SPE cartridge,then 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 33 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 of low and high concentration were both between 81%~95%;the relative standard deviations was below 10%;the limit of determination was 0.001~0.04 mg/kg(S/N=3). [Conclusion]This method is suitable for determining pesticide residues of organophosphate,organochlorine,pyrethroid,carbamate,herbicides in foods with satisfactory selectivity,accuracy and precision;it can rapidly detect 33 kinds of pesticide and the concentration level meets the requirement for detection.