| A gas chromatography-tandem mass spectrometric(GC-MS/MS) method was established for the determination of 11 dinitroaniline herbicide in grains products.The samples were extracted with acetonitrile,and cleaned up by the QuEChERS method.A rapid analysis was carried out by GC-MS/MS under multiple reaction monitoring(MRM) mode.The external standard was used for quantitative analysis.Under the optimal conditions,the calibration curves for the 11 dinitroaniline herbicides were linear in the range of 1.0-20.0 μg/L with correlation coefficients more than 0.996.The quantitation limit of the method was 5 μg/kg.The mean recoveries for rice,soybean and wheat samples at three spiked concentrations levels of 5,10,20 μg/kg were in the range of 65%-110% with relative standard deviations(RSDs,n=7) of 2.6%-10.2%. |