气相色谱法同时检测丙炔氟草胺和精异丙甲草胺在绿豆中的残留

目的]为了监测丙炔氟草胺和精异丙甲草胺在绿豆等农产品中的残留及环境安全性评价,采用气相色谱仪建立了同时检测绿豆中丙炔氟草胺和精异丙甲草胺残留量的方法。方法]样品中丙炔氟草胺和精异丙甲草胺残留先用二氯甲烷提取,再用二氯甲烷进行液-液分配,浓缩定容后用PSA和C-GCB净化,采用GC-ECD进行检测,色谱柱为DB-608。结果]在0.05~5.0 mg/L的质量浓度范围内,丙炔氟草胺和精异丙甲草胺的峰面积与质量浓度之间呈现出良好的线性关系;在添加质量分数为0.05~2.0 mg/kg时,丙炔氟草胺和精异丙甲草胺在绿豆中的添加回收率分别为90%~105%和80%~94%,相对标准偏差分别为1.1%~3.1%和0.6%~2.6%。该方法的最小检出量(LOD)均为0.05 ng,丙炔氟草胺和精异丙甲草胺在绿豆中的最低检测浓度(LOQ)均为0.05 mg/kg。结论]该方法具有灵敏度、精密度和准确度良好,杂质干扰少等特点,符合农药残留检测分析的基本要求。

Simultaneous Determination of Flumioxazin and S-Metolachlor Residues in Mung Beans by Gas Chromatography with ECD

Aims]This study aims to establish an analytical method for simultaneous determination of flumioxazin and S-metolachlor residue in mung beans by using gas chromatography with electronic capture detector(GC-ECD)to monitor the residues of flumioxazin and S-metolachlor in mung beans and other agricultural products and the environmental safety assessment.Methods]The flumioxazin and S-metolachlor residues in mung bean samples were extracted with dichloromethane,and cleaned-up through liquid-liquid partition.The concentrated solutions were purified by PSA and C-GCB before analysis.The analysis was performed on a DB-608 steel column.Results]The results showed that there were in good linearity between the concentrations of flumioxazin and S-metolachlor and their corresponding response values within the concentration of 0.05-5.0 mg/L.When the spiked level ranged from 0.05 to 2.0 mg/kg,the average spiked recoveries of flumioxazin and S-metolachlor in mung beans were 90-105 and 80-94%,respectively,with their corresponding relative standard deviation(RSD)of 1.1-3.1 and 0.6-2.6%,respectively.The limit of detection(LOD)of the method were 0.05 ng,and the limit of quantification(LOQ)of flumioxazin and S-metolachlor in mung beans samples were 0.05 mg/kg.Conclusions]The method was proved to meet the basic requirements of pesticide residue analysis on sensitivity,accuracy and precision,and to be suitable for analysis of flumioxazin and S-metolachlor residues in the environmental matrix such as mung beans.