Development of method for screening and quantification of some contaminants in rice

Liquid chromatography - high resolution mass spectrometry (LC-HRMS) developed to screen some residues in rice. Pesticides, aflatoxin B1, aflatoxin B2, aflatoxin G1, aflatoxin G2 and quaternary ammonium surfactants were detected by the optimized method. Rice samples were extracted and cleaned by QuEChERS then analyzed by QExactive system with HESI ionization source for both negative and positive modes. The C18 reversed phase column was used and the mobile phase consists of water and Methanol containing 0.1% formic acid and 10 mM ammonium formate. The method was applied successfully to analyze 60 rice samples collected in Hanoi city. The results showed that 5 pesticides in 30 rice samples from 10.3 to 160 µg/kg.