气相色谱法测定工作场所空气中甲苯的不确定度分析

目的分析气相色谱法测定工作场所空气中甲苯的不确定度。方法通过建立气相色谱法测定甲苯的数学模型,找出影响不确定度的因素,对各个不确定度因素进行评估、计算,由此计算合成不确定度,最终给出测量结果的扩展不确定度和置信水平。结果合成不确定度为0.055,扩展不确定度为0.68（k=2）;空气中甲苯含量的测定结果为（6.14±0.68）mg/m^3。结论该方法可用于气相色谱法测定工作场所空气中甲苯含量的不确定度的分析。标准曲线、重复测定、解吸效率和采样体积是影响测定结果的主要因素。

Uncertainty Analysis of Toluene in The Air of Workplace by Gas Phase Chromatography

Objective ] To evaluate the uncertainty of measuring toluene in the air of workplace by gas phase chromatography （GC）. Methods] Through establishing GC method, the mathematical model for measuring toluene was established, the factors affecting the uncertainty were deduced. Each component of uncertainty was evaluated and calculated, from which the combined uncertainty and finally the extended uncertainty and confidence level were obtained. The factors affecting the uncertainty were found. Each component of uncertainty was evaluated and calculated, from which the combined uncertainty and finally the extended uncertainty and confidence level were obtained. Results] The combined uncertainty was 0.055, extended uncertainty was 0.68（ k = 2）, and the result of measuring toluene in the air was { 6.14 ± 0.68 ） mg/m^3. Conclusion] The established method is applicable to the uncertainty analysis of GC method in the determination of toluene in the air of Workplace. The main influential factors for assay results were standard curve, repeated measurement, desorption efficiency and sampling volume.