气相色谱法测定黄瓜中吡唑萘菌胺及其代谢物

Determination of isopyrazam residues and its degradation products in cucumber by gas chromatography

目的建立黄瓜中吡唑萘菌胺及其降解产物残留的气相色谱分析方法。方法样品用丙酮提取,二氯甲烷萃取,固相萃取弗罗里硅土小柱净化,气相色谱仪氮磷检测器检测,外标法定量。结果吡唑萘菌胺及其降解产物在0.5~10μg/m L范围内线性关系良好（r≥0.998）,黄瓜中的吡唑萘菌胺及其降解产物的添加浓度为0.02、0.10、1.0 mg/kg 3个水平时,回收率在73.5%~110%之间,相对标准偏差在1.63%~13.5%之间;吡唑萘菌胺及其降解产物的检出限均达到了0.02 mg/kg。结论该方法操作简单,准确度和回收率能满足残留测定需要,适合黄瓜中吡唑萘菌胺其降解产物的残留分析。

Objective To establish a method for the determination of isopyrazam residues and its degradation products in cucumber by gas chromatography. Methods Samples were extracted with acetone, followed by extraction with methylene dichloride and cleaned up by SPE（florisil column）, then determined by gas chromatography with nitrogen phosphorus detector（GC-NPD） and quantified by external standard method. Results Each compound showed a good linear relationship in the concentration range of 0.5~10 μg/m L. The recoveries for cucumber spiked with 3 different levels of isopyrazam and its degradation products at 0.02, 0.10 and 1.0 mg/kg ranged from 73.5% to 110%, with RSD between 1.63% and 13.5%, and the limit of quantitation（LOQ） for all of them was 0.02 mg/kg. Conclusion This method is simple, the accuracy and recovery rate can meet the needs of the residue determination, and it can be applied for the detection of isopyrazam residues and its degradation products in cucumber.