超声辅助提取-QuEChERS/GC-MS法快速测定土壤中六六六和滴滴涕

Rapid determination of hexachlorocyclohexane and dichlorodiphenyltrichloroethane in soil using ultrasound-assisted QuEChERS/GC-MS

基于QuEChERS技术并辅助快速超声提取,建立了土壤中HCH,DDT快速检测方法。土壤样品经正己烷:丙酮=1:1(V/V)辅助超声提取、N-丙基乙二胺(PSA)与C18混合分散剂净化,利用GC-MS外标法定量分析。6种目标农药线性范围均超过3个数量级;3种添加水平(2.0,20,80.0μg/kg)下,土壤中8种农药平均回收率为82.2%~102.4%,相对标准偏差均小于12.5%;方法检出限(LOD)为0.06~0.27μg/kg,定量限(LOQ)为0.21~0.89μg/kg,均低于农田土壤HCH,DDT的风险筛查值(GB 15618-2018)。方法可满足实际土壤批量、快速检测需求。

A rapid analytical method for the determination of hexachlorocyclohexane(HCH)and dichlorodiphenyltrichloroethane(DDT)residues in soil using anultrasound-assisted QuEChERS technique coupled with gas chromatography(GC)-mass spectrometry(MS)was established.Target compounds in soil samples were effectively extracted by mixture of n-hexane and acetone(V/V=1:1)with ultrasonic extraction for 30 min,and then were purified by a mixed adsorbent(primary secondary amine(PSA)and C18),followed by GC-MS analysis.The linear ranges of the established method were 0.5-500μg/kg with more than three orders of magnitude for six target compounds.At three spiked concentration levels(2.0,20.0 and 80.0μg/kg),the average recoveries of the established method were 82.2%-102.4%with the relative standard deviations(RSDs)less than 12.5%.The limits of detection(LODs,S/N=3)and the limits of quantitation(LOQs,S/N=10)of the established method were 0.06-0.27μg/kg and 0.21-0.89μg/kg,which were lower than the risk screening values of HCH and DDT in farmland soil in China.The method can meet actual needs for rapid and batch detection in soil.