二次热解吸-气相色谱法测定工作场所空气中苯系物

Determination of Benzene Series in Workplace Air by Two Stage Thermal Desorption Gas Chromatography

为了建立二次热解吸-气相色谱法测定工作场所空气中苯系物,采用Tenax-TA解析管吸附采集样品后,经热脱附仪二次热解吸-冷阱捕集,气相色谱-氢火焰离子化检测器(FID)分离检测,标准曲线法定量.结果显示,苯系物在0.50~50μg/mL的浓度范围内与峰面积呈良好的线性关系,相关系数均大于0.999 0.其检出限为:0.002~0.03μg/mL,最低检出浓度为0.013~0.20μg/m^3(以采集1.5 L空气样品计),平均加标回收率在97.53%~100.4%之间,相对标准偏差(RSD)为1.0%~3.2%之间.该法操作简单、快速灵敏、准确可靠,适用于工作场所空气中低浓度苯系物的分离检测.

We established a method for the determination of benzene series in workplace air by two stage therm aldesorption gas chromatography. The air sample was collected with Tenax-TA and was trapped by two stage therm aldesorption-cold trap. After separating with the flame ionization detector(FID)-gas chromatography,the quantitative was determined by standard curve. We found the concentrations of benzene series presented a good linea rrelationship with peak area when they were within 0.50-50 μg/m L,and the correlation coefficients of the standard curve were all above 0.999 0. The results showed that the detection limits of the method were 0.002-0.03 μg/m L,and the minimum detectable concentrations were 0.013-0.20 μg/m^3(sample volume was 1.5 L). The recovery rates of benzene series were in the range of 97.53%-100.4% and the relevant standard deviations(RSD)were in the range of 1.0%-3.2%. The method is simple,fast,accurate and reliable,and is suitable for the separation and detection of low concentration of benzene series in workplace air.