Large-scale multi-class herbicides analysis in oilseeds by rapid one-step QuEChERS-based extraction and cleanup method using liquid chromatography-tandem mass spectrometry.

Abstract

A simple, sensitive and rapid method is proposed for simultaneous determination of 120 various classes of herbicides in oilseed samples. A one-step QuEChERS-based approach to extraction and cleanup has been developed. LC-MS/MS was used to evaluate the proposed sample treatment methodologies. The new one-step QuEChERS strategy was compared to other methodologies previously used for elimination of co-extracts from fatty matrices. For validation purposes, recovery studies were carried out at 5, 50 and 500µgkg(-1) levels for rapeseed, sunflower seeds and soybean. The optimized method yielded a small matrix effect (-20-20%) for 82% of the tested compounds. We was found to reduce matrix effects more effectively without significantly decreasing analyte recoveries. Throughout the validation experiments, 70-120% overall recoveries were achieved with RSDs<20% for most herbicides. The validated method was employed in analysis of ninety real rapeseed samples.