| Chlorobenzene compounds（CBs）are typical persistent organic pollutants prevalent in the environment,which are widespread concern over the world.It is highly toxic,accumulative and persistent in the environment and organisms,and has strong carcinogenic,teratogenic and mutagenic effects.With the rapid development of industry,agriculture and urbanization in recent years,the pollution of chlorobenzene compounds is becoming more and more serious.At present,there is no systematic standard monitoring method for chlorobenzene in soil in China.The test studied pretreatment and analysis detection method of 11 Chlo-robenzenes in soil,which included 1,2-Dichlorobenzene,1,3-Dichlorbenzene,Nitro-p-Dichlorobenzene,1,2,4-Trichlorobenzene,1,2,3-Trichlorobenzene,1,3,5-Trichlorobe-nzene,1,2,3,5-Tetrac-hlorobenzene,1,2,4,5-Tetrachlorobenzene,Pentachlorobenzene,Hexachlorobenzene.It provides a reference method for environmental analysis in this field.The chromatographic conditions for the determination of 11 chlorobenzene compounds in soil by gas chromatograph were determined.Using DB-1701 column,the program of column temperature box:the initial temperature is at 50℃and keeps for 1 min,8℃·min-1 to 150℃and keeps for 3 min,finally,it is raised to 220℃centigrade at8℃·min-11 and keeps for 2 min.The combined determination of 11 kinds of chlorobenzene compounds in soil with accelerated solvent extraction,the recovery rate is stable and reproducible,the organic solvent is saved,time is saved,and the advantages of multiple samples can be extracted at one time.The shortcoming is that the price of the instrument is high.The extraction efficiency of Soxhlet extraction and accelerated solvent extraction was compared.The recovery rate of Soxhlet extraction is between 51.5%and 71.1%.However,during the extraction process,a large amount of water vapor enters the extraction solution,which is difficult to remove water.The recovery rate of accelerated solvent extraction is between 81.6%and 98.3%.By comparing the two extraction methods,the accelerated solvent extraction method was selected as the extraction method of 11 chlorobenzene compounds in soil.11 kinds of chlorobenzene compounds in soil by solid phase extraction purification have different fillers and elution solvents,which have high flexibility and effectiveness for the purification of the samples.The QueEChERS purification method and solid phase extraction column purification method were compared.QueEChERS purification method using PSA（25mg）+GCB（2.5mg）specifications of the purification tube has the best recovery rate,ranging from 63.1%to 76.4%.Solid phase extraction purification method with Florisil column,5%acetone/hexane as eluent and eluent dosage above8mL has the best performance.The recovery range is between 71.8%and 83.2%.Considering that the components of the soil are complex when determining the actual soil samples,the solid phase extraction column（Florisil column）is the best way to purify the soil.The method for the determination of 11 kinds of chlorobenzene compounds in soil-"accelerated solvent extraction-floret silica column purification-electron capture detector gas chromatography"was established,and the external standard method was used for quantitative analysis.The standard curve of 11 kinds of chlorobenzene compounds was drawn.The linear correlation coefficient of the standard curve was above 0.999.The detection limit of the method was 1.6×10-3μg·kg-1—6.5×10-2μg·kg-1.The soil samples（clay,loam,sandy soil）and sediment samples（river type and lake reservoir type）were recoverable by standard addition.The relative standard deviations are within 20%.The recovery rate is between 64.83%and 90.01%.According with the requirements of the《technical guidelines for the revision of environmental monitoring and analysis standards（HJ 168-2010）》. |
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