one-step quechers-based approach to extraction and cleanup in multiresidue analysis of sulfonylurea herbicides in cereals by liquid chromatography–tandem mass spectrometry

A one-step quick, easy, cheap, effective, rugged, and safe (quechers)-based approach to extraction and cleanup in multiresidue pesticide analysis is presented for the first time. the experiment was designed to detect 23 sulfonylurea herbicides in a complex cereal matrix. the challenge was to choose the optimal conditions of one-step extraction and cleanup. chitin, diatomaceous earth, and octadecyl were investigated as cleanup sorbents. chitin, citrate buffer, and 1 % formic acid in acetonitrile yielded the best results. the effectiveness of sulfonylureas extraction was evaluated at three different spiking levels (0.005, 0.05, and 0.5 mg kg−1) in wheat, rye, and oat using liquid chromatography–tandem mass spectrometry. the one-step quechers provided recoveries in the 70–120 % range for 23 sulfonylureas in all cereal matrices. matrix effects were evaluated and were not significant for all herbicides, showing suppression or enhancement (between −19 and 13 %). precision, calculated as relative standard deviation (rsd), was below 20 %. a linear dependence was observed in the range of 0.005–2.0 mg kg−1, and the correlation coefficient was r 2 > 0.999. expanded measurement uncertainty was estimated to be between 9 and 24 %, on average. the validated method was employed in analysis of 89 real grain samples.