加速溶剂萃取-磁固相萃取净化-气相色谱-质谱法测定土壤中16种多环芳烃和23种有机氯残留

Determination of 16 polycyclic aromatic hydrocarbon and 23 organochlorine residues in soil by accelerated solvent extraction and magnetic solid phase purification-gas chromatography-tandem mass spectrometry

建立了加速溶剂萃取(ASE)、磁固相萃取净化(MSPE)、气相色谱-质谱(GC-MS)测定土壤中多环芳烃和有机氯残留的方法。ASE萃取溶剂为丙酮-正己烷(1∶1,v/v),萃取温度为100℃,萃取压力为11.032 MPa,加热时间为5 min,静态萃取时间为5 min,循环萃取3次,冲洗体积为60%萃取池体积,氮气吹扫100 s。然后采用室温制备法自制ZIF-8/nZVI磁性材料用于净化萃取液,将净化液浓缩定容后进行GC-MS测定。多环芳烃和有机氯的线性范围为5~200μg/kg,线性相关系数(r2)均大于0.99;目标物的检出限(LOD,S/N=3)为0.04~1.21μg/kg。所建方法成功用于土壤样品中16种多环芳烃和23种有机氯的测定,在3个加标水平下得到的加标回收率为63.9%~112.1%,相对标准偏差(RSD)为0.4%~26.2%。研究结果表明,该方法具有灵敏度高、重现性好、回收率高等特点,适用于土壤中多环芳烃和有机氯残留的检测。

A method combining accelerated solvent extraction(ASE)with magnetic solid-phase extraction(MSPE)and gas chromatography-mass spectrometry(GC-MS)was developed for the simultaneous detection of polycyclic aromatic hydrocarbon(PAH)and organochlorinepesticide(OCP)residues in soil samples.The analytes in the soil samples were extracted using an acetone/n-hexane(1∶1,v/v)mixture for 5 min at 100℃.Then,the extraction pool was heated for 5 min under an extractive pressure of 11.032 MPa for three cycles.The extraction pool was washed with an acetone/n-hexane(1∶1,v/v)mixture accounting for 60%of the pool volume,followed by nitrogen purging for 100 s.The extract was purified by MSPE using self-made magnetic ZIF-8/nZVI materials at room temperature.The analytes were detected by GC-MS/MS.Under the optimized conditions,good linearities were obtained for the 16 PAHs and the 23 OCPs in the range of 5-200μg/kg,with correlation coefficients(r2)above 0.99.The limits of detection(LODs)were 0.04-1.21μg/kg.At three spiked levels in the soil samples,the recoveries of the 39 analytes were between 63.9%and 112.1%,with relative standard deviations(RSDs)between 0.4%and 26.2%.The method was demonstrated to be successful for the determination of 16 PAH and 23 OCP residues in soil samples,with good recoveries.