NLow matrix effect pretreatment method based on gas-liquid micro-extraction technique for determining multi-class pesticides in crops.

A low matrix effect pretreatment method by Gas-liquid microextraction technique (GLME) combined with ultrasound assisted extraction (UAE-GLME) has been developed for fast analysis of 41 multi-class pesticides in different crop samples. Extraction and cleanup procedures were completed within 20 min, and the impact of matrix effects in potato, lentil, corn and soybean matrices were systematically evaluated. As high as 97.6% pesticides treated by UAE-GLME experienced low matrix effect, and up to 99% pesticides except parathion-methyl in lentil samples were categorized as medium matrix effect. Good trueness (recoveries of 61.3-115.8%) and precision (RSD≤20%) were demonstrated by the UAE-GLME method, with MLOQs ranged from 0.005 to 0.02 mg kg-1. This method detected 2-phenylphenol, pyrimethanil, triadimefon and tebuconazole in the range of 0.008-0.012 mg kg-1 in real food samples. The multiresidue analysis feature of GLME has been validated, which displays further potential for high-throughput determination of organic pollutants in foods with distinctive properties.