基于二硫化碳解吸前处理技术GC-FID测定工作场所空气中烷烃

Determination of alkanes in the air of workplace with GC-FID method based on pretreatment technology of carbon disulfide desorption

为建立工作场所空气中正戊烷、正己烷、正庚烷3种烷烃有毒物质的溶剂解吸-气相色谱检测法,采用二硫化碳解吸脱附作为前处理手段,利用TG-5MS毛细管柱对目标物质进行分离,以氢火焰离子化检测器进行检测,保留时间定性,峰面积响应值定量,外标法计算。结果表明:该方法能够很好地分离并检测定量出正戊烷、正己烷、正庚烷各自含量,各自标准曲线相关系数均达到0.999 0,精密度在1.83%~5.79%范围内,实际样品加标回收率在89.6%~97.8%之间,该方法检出限:正戊烷为0.008 6μg/m L,正己烷为0.200 0μg/m L,正庚烷为0.056 6μg/m L。

In order to establish solvent desorption-gas chromatography measuring method for 3 kinds of alkanes（ npentane,n-hexane and n-heptane） in the air of workplace,through using carbon disulfide desorption as pretreatment,the target mass is firstly separated by TG-5MS capillary column,and then is determined by hydrogen flame ionization detector.The retention time is used to carry out qualitative analysis,the peak area response value is used to determine amount and the external standard method is used to do calculation. The results show that n-pentane,n-hexane and nheptane can be well separated and detected quantitatively by using this method and the correlation coefficients of standard curves for three alkanes all reach 0. 999 0,with relative standard deviations of determination in the range of 1. 83%-5. 79% and recovering rate of samples in the array of 89. 6%-97. 8%.The detection limit of this method is： 0. 008 6 μg·mL^（-1） for n-pentane,0. 200 0 μg·mL^（-1） for n-hexane,and 0. 056 6 μg·mL^（-1） for n-heptane.