a Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin 300191, PR China b Agilent Technologies (China) Company, Ltd., Beijing 100102, PR China

Abstract:
A simple and high-throughput multiresidue pesticide analysis method was developed and validated for 219 pesticides in cereals (corn, wheat flour and rice) based on QuEChERS (quick, easy, cheap, effective, rugged, and safe) procedure combined with gas chromatography–triple quadrupole mass spectrometry (GC–MS/MS). Different buffer system (acetate- and citrate-buffered) and sample to solvent ratios (sample amount) were compared in the modified QuEChERS procedure to get better recovery and clean-up results. The limits of quantification (LOQ) ranged between 5 and 50 ug kg-1, and for the majority of the pesticides the LOQ were 5 ug kg-1, which were below the regulatory maximum residue limits. The coefficient of determination (r2) was >0.99 within the calibration linearity range of 2–200 lg kg1 for the majority of the pesticides. Most recoveries at 5, 10, 20, 50, 100 and 200 ug kg-1were in the range 70–120% (n = 6) with associated RSDs < 20% indicating satisfactory accuracy.

Keywords:    Protein absolute quantitation    Transition    Intelligent selected reaction monitoring    Multiresidue analysis    Cereal    QuEChERS    Gas chromatography–tandem mass    spectrometry