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.