Determination of pyroxasulfone residues in plant derived foods by QuEChERS combined with gas chromatography-triple quadrupole mass spectrometry

Abstract

ObjectiveTo develop a method for the determination of pyroxasulfone residue in plant derived foods by QuEChERS combined with gas chromatography-triple quadrupole mass spectrometry.MethodsPyroxasulfone in rice， wheat， sorghum， corn， soybean， peanut， sweet potato， potato and sunflower seeds were extracted with ethyl acetate， and cleaned up with primary-secondary amine， stearyl bonded silica gel and anhydrous magnesium sulfate as dispersive solid-phase extraction sorbent. After centrifugation and filtration， the target compound was analyzed by gas chromatography-triple quadrupole mass spectrometry， and quantified by matrix matching external standard method. The extraction solvents， extraction method， purification method and instrument conditions were optimized. The matrix effect was investigated and the optimal pretreatment method and instrument conditions were determined.ResultsUnder the optimal conditions， the calibration curves were linear in the range of 0.000 5-0.05 mg/L with correlation coefficients above 0.999. The recoveries were 83.8%-104.3% at four concentration levels with relative standard deviations （RSDs， n=6） of 2.6%-6.7%. The quantitation limit of pyroxasulfone was 0.001 mg/kg.ConclusionThe method is simple， rapid and sensitive， and could meet the requirements for the detection of pyroxasulfone residue in plant derived foods.

Keywords

• pyroxasulfone
• plant derived foods
• quechers-gas chromatography-triple quadrupole mass spectrometry