中文摘要：

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。

英文摘要：

An enantioselective method was developed for separation and determination of six chiral polychlorinated biphenyls（PCBs） including PCB 91,95,136,149,176 and 183 in lotus root,stem, leaf and sediment by GC-MS.After optimizations of instrumental parameters for enantiomeric separation and investigations of sample preparations including accelerated solvent extraction（ASE） parameters,extraction solvents and cleanup methods,PCBs enantiomers were extracted from samples by ASE with n-hexane/acetone（1：1,V/V） at 100℃and 10.3 MPa for 10 min.The extracts were orderly sulphonated by sulfuric acid,purified by Florisil solid phase extraction column,reconstituted with isooctane after being concentrated,and respectively detected by GC-MS with Chirasil-Dex and BGB-172 columns.For all PCBs enantiomers,good linearities were obtained in the concentration range of 0.5—100μg/L,and recoveries of spiked samples at 0.25,2.5 and 25μg/kg levels were 82.8%-117.0%with relative standard deviations（RSD） of 1.5%- 13.6%.Limits of detection （LOD） and limits of quantification（LOQ） were 0.01 -0.02μg/kg and 0.025-0.04μg/kg, respectively.The real samples analysis showed that chiral PCBs were not detected in lotus roots from markets,but higher concentrations were found in lotus root and sediment from contaminated area. The concentrations of PCB 91-2,PCB 951 and（＋ ）- PCB 136 in lotus root,stem and leaf were respectively higher than those of their enantiomers,while no significant differences between two enantiomers of PCB 149,176 and 183.