分散固相萃取-超声辅助分散液液微萃取/高效液相色谱法测定土壤中溴氰菊酯残留

Determination of Deltamethrin Residues in Soil by Dispersive Solid Phase Extraction and Ultrasound-assisted Dispersive Liquid-liquid Microextraction Coupled with High Performance Liquid Chromatography

建立了以分散固相萃取-超声辅助分散液液微萃取为样品前处理技术,结合高效液相色谱法（HPLC）测定土壤中溴氰菊酯。样品用甲醇∶水（1∶4,V/V）提取,经布氏漏斗减压抽滤,滤液经N-丙基乙二胺（PSA）、C18、石墨炭黑粉（GCB）净化后,用氯仿萃取,超声,离心后沉积相进行HPLC测定。对分散固相萃取吸附剂的选择及影响分散液液微萃取的因素进行了优化,在最优条件下,溴氰菊酯的富集倍数达到565倍,线性范围为0.005～2.5mg/kg,线性相关系数为0.9998,检出限为0.001mg/kg,平均加标回收率为70.3%～94.5%,相对标准偏差为2.5%～4.7%。该方法具有简便快速、准确灵敏、萃取效率高等特点,可用于土壤中溴氰菊酯残留检测。

A novel method for the determination of deltamethrin in soil was developed by dispersive solid phase extraction and ultrasound-assisted dispersive liquid-liquid microextraction coupled with high performance liquid chromatography（HPLC）.The analytes in the soil were extracted with methanol∶water（1∶4,V/V）solution,and then filtrated through Buchner funnel.The filtrate was transferred into a centrifugal tube with 25 mg primary secondary amine（PSA）,15 mg C18 and 10 mg graphitic carbon black（GCB）powder,which was followed by the extraction with chloroform.After ultrasonic dispersion and centrifugation,the sedimentary phase was determined by HPLC.The sorbent and some important parameters that affected the extraction efficiency were studied.Under the optimum conditions,the enrichment factor of the deltamethrin was about 565.The limit of detection was 0.001mg/kg（S/N=3）.The linearity range was 0.005-2.5 mg/kg and the correlation coefficient was 0.9998.The average recoveries ranged from 70.3%to 94.5%,with the relative standard deviation between 2.5%and 4.7%.This method is simple and accurate,with high extraction efficiency and little consumption of organic solvent.In addition,it is suitable for the determination of deltamethrin residues in soil samples.