High Throughput Analysis Of N-Methyl Carbamate Pesticides In Cereals And Beans By Dual Countercurrent Chromatography And Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometry

We developed a new analytical method for analysis of N-methyl carbamate pesticides in cereals and beans using dual counter-current chromatography (dual CCC) and liquid chromatography-electrospray ionization tandem mass spectrometry (ESI LC/MS/MS). After pesticides were extracted from cereals and beans with ethyl acetate, each extract was cleaned up by dual CCC using a non-aqueous binary solvent system composed of n-hexane-acetonitrile and analyzed by ESI LC/MS/MS with a short column. The average recoveries from cereals and beans fortified at the level of 0.01 ppm ranged from 73.9 to 119.6%, with the coefficients of variation from 0.7 to 6.8%. At the fortified level of 0.5 ppm, the recoveries ranged from 72.1 to 117.1% with coefficients of variation from 0.4 to 9.3%. The present analytical method of N-methyl carbamate pesticides in cereals and beans is considered to be useful for monitoring the pesticide residues in cereals and beans.