基于QuEChERS净化-气相色谱法同时测定蔬菜中6种有机磷类农药残留

建立了QuEChERS（Quick，Easy，Cheap，Effective，Rugged and Safe）法-气相色谱法测定蔬菜中6种有机磷农药残留量的检测方法.样品用1%乙酸乙腈提取，经N-丙基乙二胺（PSA）和无水硫酸镁分散固相萃取净化，气相色谱火焰光度检测器测定.考察了QuEChERS法在两种不同体系（氯化钠盐析和乙酸盐缓冲体系）的提取净化效果.试验结果表明，在乙酸盐缓冲体系中，有机磷农药残留更加稳定，回收率更高.6种有机磷农药残留在0.2~10.0 mg/L之间线性关系良好，相关系数（R²）均大于0.999，检出限在0.003 5~0.015 mg/L之间.低、中、高3个添加水平的回收率在78.5%~106.3%之间，相对标准偏差在1.4%~6.3%之间.方法简单、快捷，准确可靠，适合大批量样品农残检测.

Determination of Six Organophosphrous Pesticide Residues in Vegetables Using QuEChERS Purification Coupled with Gas Chromatography

A method of QuEChERS(Quick, Easy, Cheap, Effective, Rugged and Safe) sample preparation coupled with gas chromatography has been established for the determination of six organophosphrous pesticide residues in vegetables. The samples were extracted with acetonitrile and cleaned up by dispersive solid phase extraction using N-propyl ethylenediamine(PSA) and magnesium sulfate as sorbents, then determined on a gas chromatograph with a flame photometric detector(FPD). Two different extraction systems of sodium chloride precipitation and acetate buffer for the method of QuEChERS were studied, and the results show that organophosphorus pesticide residues were more stable and with higher recoveries in the acetate buffer extraction system. Six organophosphorus pesticide residues, in the range of 0.2~10.0 mg/L had a good linear relationship, with correlation coefficients more than 0.999. The limits of detection were in the range of 0.003 5~0.015 mg/kg. The recoveries of six organophosphorus pesticide residues in various spiked levels ranged from 78.5% to 106.3%, with RSDs of 1.4%~6.3%. The method showed the advantages of simplicity, rapidity and reliability and meet the demands of the determination pesticide residues for batch samples.