炭管采集气相色谱法测定空气中丁醚的实验研究

Experimental Research on Gas Chromatographic Determination for Butyl Ether Collected by Activated Charcoal in the Workplace Air

[目的 ]研究炭管采集空气中丁醚的气相色谱分析方法。 [方法 ]活性炭吸附空气中丁醚 ,样品经加热解吸 ,色谱检测。 [结果 ]当空气中丁醚浓度范围在 2 69～ 10 77mg/m3 (参照美国标准 10 0ppm ,相当于 5 3 3mg/m3 )时 ,其方法的变异系数为 1 1% ,回归方程式y =96 1+17 79x ,r =0 9998,最低检测限 4 4× 10 -3 μg(进样 2ml)。平均解吸效率为97 3 % ;穿透容量 (BTV) 14 1mg。活性炭吸附 10 77μg丁醚后 ,样品放置一周 ,回收率仍可达 93 7%。本法的测定范围上限取决于炭管的吸附量 ,而该吸附量可随空气中丁醚的浓度及其它物质 (醚类 )而变化。 [结论 ]本方法可应用于车间环境中丁醚浓度的测定。

Objective] GC analytical method for butyl ether in the workplace air using sampling by charcoal tube was studied. [Method] Adsorption on charcoal,thermal desorption and analysis by GC(FID) were performed. [Results] The coefficient of variation for the whole analytical method in the range of 269～1077mg/m 3 was 1 1%.Regression formula was y=96 1+17 79x,r =0 9998.Detection limit was 4 4×10 -3 μg(injection for 2ml).Desorption efficiency was 97 3%,breakthrough volume was 14 1mg.After taking 1077μg of butyl ether with the charcoal tube,it could be stabilized in seven days,its recovery efficiency was 93 7%.The upper detection limit of the method is dependent on the adsorptive capacity of the charcoal tube.This capacity varies with the concentration of butyl ether and other substances as ethers in the air. [Conclusion] The method can also be used to determine butyl ether and the simultaneouly presented ethers of two or more substances in the workplace air by simply changing gas chromatographic conditions from isothermal to a temperature programmed mode of operation.