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采用气相色谱质谱(GC MS)建立了莲藕、荷叶、荷茎及池塘底泥中6种手性多氯联苯(PCBs)PCB 91,95,136,149,176和183的分离分析方法。优化了对映体的仪器分离检测条件,考察了前处理中加速溶剂萃取(ASE)参数、提取剂以及净化方式等对方法的影响,最终确定采用正己烷丙酮(1:1,V/V)在萃取温度100℃、压力10.3 MPa下静态提取10 min,提取液经H_2SO_4磺化后过Florisil小柱净化,洗脱液经浓缩并用异辛烷定容后,用分别配有Chirasil Dex和BGB-172手性毛细管色谱柱的GC-MS检测。6种手性PCBs对映体的线性范围为0.5～100μg/L,在0.25,2.5和25μg/kg添加浓度的回收率为82.8%～11 7.0%,相对标准偏差(RSD)为1.5%～13.6%,检出限为0.01～0.02μg/kg,定量限为0.025～0.04μg/kg。将本方法应用于实际样品的测定,在市售莲藕未检出6种手性PCBs,而污染区的莲藕、荷茎、荷叶及其生长底泥中均含有较高浓度手性PCBs,并且莲藕、荷茎和荷叶中PCB 91-2,PCB 95-1和(+)PCB 136的浓度均高于其对映体,而PCB 149,1 76和1 83的两个对映体之间均无显著的浓度差异。
Gas chromatography-mass spectrometry (GC-MS) was used to separate and analyze six kinds of chiral PCBs PCBs 91, 95, 136, 149, 176 and 183 in lotus root, lotus leaf, The conditions of separation and detection of enantiomers were optimized. The effects of accelerated solvent extraction (ASE) parameters, extractants and purification methods on the performance of the method were investigated. The results showed that n-hexane acetone (1: 1, V / V) The extract was subjected to static extraction at 100 ℃ and pressure of 10 MPa for 10 min. The extract was purified by Sulfonation of H_2SO_4 and purified on a Florisil cartridge. The eluate was concentrated and eluted with iso-octane, and then eluted with Chirasil Dex and BGB- 172 Chiral Capillary GC-MS Detection. The linear range of enantiomers of six chiral PCBs ranged from 0.5 μg / L to 100 μg / L, with recoveries of 82.8% ~ 11 7.0% and relative standard deviations (RSDs) of 1.5% ~ 13.6 at 0.25, 2.5 and 25 μg / %, The detection limit of 0.01 ~ 0.02μg / kg, the limit of quantification of 0.025 ~ 0.04μg / kg. The method was applied to the determination of the actual samples. Six kinds of chiral PCBs were not detected on the commercially available lotus root, while the higher concentrations of chiral PCBs were contained in the lotus root, The concentrations of PCB 91-2, PCB 95-1 and (+) PCB 136 in lotus root, lotus and lotus leaf were both higher than those of their enantiomers, whereas the two enantiomers of PCB 149,1 76 and 1 83 No significant difference in concentration.