NY/T 761—2008标准中27种农药残留前处理方法的优化
Optimization of Pretreatment Methods for 27 Pesticide Residues in NY/T 761—2008 Standard
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摘要: 微量化、低毒化、快速化和低成本是样品前处理的发展趋势. 建立了果蔬中27种农药残留的快速前处理气相色谱法, 对标准NY/T 761—2008中不同种类农药残留的前处理方法进行优化, 并对改进后的方法进行可行性研究. 使用1%乙酸-乙腈溶液快速提取, 采用离心代替原法中过滤与静置, 经石墨化炭黑(GCB)净化处理, 气相色谱法进行检测分析. 采用优化后的前处理方法测定27种农药残留, 加标回收率在72.1%~111.0%之间, 相对标准偏差(RSD)在0.6%~14.5%之间, 标准曲线的线性关系良好, 方法检出限为0.000 1~0.006 mg/kg. 对多种蔬菜水果的测试结果显示平均回收率高达98.8%. 优化后的方法仍有较高的回收率和准确度, 而且减少了器皿和溶剂的使用, 降低了有机废液和废气的排放量, 适应批量样品前处理要求, 可在一般情况下替代NY/T 761—2008的前处理方法.Abstract: Miniaturization, low toxicity, rapidity and low cost are the development trend of sample pretreatment. A new method to detect 27 pesticide residues in fruits and vegetables by the rapid pretreatment of gas chromatography has been developed. The different pretreatment methods of different types of pesticide residues in the standard NY/T 761—2008 were integrated and optimized, and the feasibility of the improved method was carried out. The pesticide residues in samples were extracted with 1% acetic acid-acetonitrile solution. Then, the pesticide residues in the supernatant were cleaned up with graphitized carbon black (GCB) before being subjected to gas chromatographic (GC) analysis. The results showed that good linearity was observed for all 27 analytes with correlation coefficients above 0.999. The limits of detection (LODs) were in the range of 0.000 1~0.006 mg/kg. The recoveries were in the range of 72.1%~111.0% and the relative standard deviations (RSD) were less than 14.5% (n=3). The analysis results of several vegetables confirmed that the pretreatment method can meet the requirements of the multi-pesticide residue analysis and determination, and the average recovery was as high as 98.8%. The optimized pretreatment method not only has high sensitivity, accuracy and convenience, but also greatly reduces the discharge of organic waste liquid and waste gas, improves the detection efficiency and meets environmental friendly requirements, the method meets the requirements of batch sample pretreatment, and provides a more effective guarantee for the quality and safety of agricultural products.