建立气相色谱-正构烷烃多内标法准确检测苯系物的新方法，研究苯系物色谱分离多个内标物选择的依据，优化实验条件．样品经二硫化碳解吸30 m in ，毛细管气相色谱火焰离子化检测器检测，保留时间定性，正构烷烃辅助定性，以正庚烷为内标定量．苯、甲苯和二甲苯的线性范围分别为0．0175～0．7012 mg/mL、0．0173～0．6935 mg/mL和0．0172～0．6889mg/mL ；相关系数分别为0．9996、0．9997和0．9999（以正庚烷为内标）．苯、甲苯和二甲苯的最低检测限分别为0．14μg/mL、2．49μg/mL、1．45μg/mL ；相对标准偏差分别为0．9％～1．0％、0．1％～3．8％和0．2％～1．5％之间．试验结果表明该方法可消除复杂基体的干扰，定性定量准确，简便快速、实用性强，可用于室内空气、胶水和油漆等多种样品中苯系物的监测．%To develop a new method for the seperation and quantification of the benzene homologues by GC with n-alkanes as internal standard .The experiment conditions were optimized and the advantages of n-alkanes as internal standard were discussed .Benzene homologues were desorbed by carbon disulfide for 30 min and analyzed by GC-FID . Retention time was used for qualitative analysis and peak area was for quantitative analysis with n-alkanes as internal standard .The linear ranges of benzene ,toluene and xylenes were 0 .017 5-0 .701 2 mg/mL ,0 .017 3-0 .693 5 mg/mL and 0 .017 2-0 .688 9 mg/mL with correlation coefficients 0 .999 6 ,0 .999 7 and 0 .999 9 respectively (n-heptane as internal standard material) ,also the detection limits of benzene ,toluene and xylenes were 0 .14 μg/mL ,2 .49 μg/mL and 1 .45 μg/mL respectively .When adding standard material of benzene , toluene and xylenes at low , middle and high concentrations , the relative standard deviation (RSD ) were 0 .9% -1 .0% ,0 .1% -3 .8% and 0 .2% -1 .5% . Results indicated that the proposed method was accurate ,reliable and sensitive .It has been applied to the analysis of different samples from plant with satisfactory results ,which was an ideal assay for the determination and monitoring of benzene homologues in indoors air and chemical products .
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