| Persistent organic pollutants (POPs) are difficuLt to degrade, can be transported in a long distance and be accumμLated in the environment. POPs have become a hot issue in the environmental field because of their carcinogenic, teratogenic, mutagenic effects as well as effects of environmental hormones, and that they may lead to disruption of organism endocrine, dysfunction of reproductive as well as immune. Twelve kinds of POPs such as and BHC have been included into be the target items of national mμLti-objective regional geochemistry survey project in 2005 by China Geological Survey, which promotes the level of POPs monitoring and pollution investigation further in our country.A method for rapid determination of total PCBs in soil and sediment has been established with gas chromatography-mass spectrometry (GC-MS) in the paper. The matrixs of soil and sediment samples are complex, so the purification becomes the key step to the analysis of such samples. In this paper, the sample was extracted by Accelerated Solvent Extraction (ASE), and the extract was cleaned up by special solid phase extraction (SPE) column, the total PCBs were determined with GC-MS. The average recoveries of total polychlorinated biphenyls (PCBs) were between 83.9 and 105.8%. The relative standard deviations (RSD%) were between 3.48 and 8.41%(n=6). The method detection limits (MDL) of the total PCBs was 2.25μg·kg-1.The method was used for fast screening analysis of total PCBs in soil and sediment due to its rapidity, sensitivity and preciseness.This paper has focused on the study of gas chromatography-ion trap tandem mass spectrometry (GC-IT-MS/MS). The influence on sensitivity by MS/MS instrument parameters was explored systematically, mainly including the choice of the parent ions and the daμghter ions, excitation storage level, collision-induced dissociation voltage, automatic gain control, scanning cycles/scanning time, etc. A method for the determination of 25 organochlorine pesticides (OCPs) and PCBs in soil and sediment with GC-IT-MS/MS by ASE and SPE was established. The sensitivity of GC-IT-MS/MS has been significantly improved compared to GC-MS. The MDL of 17 OCPs was 0.045-0.274μg·kg-1; The MDL of 8 PCBs was 0.028-0.049μg·kg-1. When the spiked level were 0.345μg·kg-1and 3.45μg·kg-1,the spiked average standard recoveries in soil samples were 69.59%-110.08% and relative standard deviation were 3.21%-13.95%(n=10). A large number of difficμLt samples were determined with GC-MS and GC-IT-MS/MS respectively. The resμLts showed that IT-MS/MS can eliminate a large number of interference factor, reduce the possibility of false positive and false negative resμLts more effectively. Besides, the more "clean" samples can be determined directly by GC-IT-MS/MS without purification, greatly simplified the pretreatment.This paper explored preliminarily the isotope dilution-IT-MS/MS method for the determination of OCPs and PCBs in soil and sediment, studied the choice of isotope-labeled surrogates, the impact of cycles of concentration on the detection limit, the influences of spiked concentrations and equilibrium time of quantitative isotope internal standard on the quantitative resμLts, and so on. An outline of further work on the determination of OCPs and PCBs in soil and sediment with isotope dilution-IT-MS/MS has been formed throμgh this preliminary investigation.
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