气相色谱质谱法测定室内空气中22种总挥发性有机物不确定度评定

Evaluation of Uncertainty in Determination of Indoor Air 22 Kinds of Total Volatile Organic Compounds by Gas Chromatography-Mass Spectrophotometry

采用气相色谱质谱法(GC-MS)测定室内空气中的22种总挥发性有机物(TVOC),识别测试过程中的不确定度来源,对测量结果进行不确定度评定。根据来源对测量重复性进行A类不确定度评定,对温度、大气压、体积等采样参数,曲线拟合、标准物质进行B类评定,计算合成相对标准不确定度及扩展不确定度。结果表明:某室内空气中总挥发性有机物含量为0.410 9 mg·m^(-3),扩展不确定度为0.362 6 mg·m^(-3)(k=2)。不确定主要来源为标准曲线的拟合。

The indoor total volatile organic compounds(TVOC)were determined by gas chromatography-mass spectrophotometry(GC-MS).The sources of uncertainty in the test process were discriminated,and the uncertainty of test results was evaluated.The measurement repeatability were evaluated by the class A uncertainty evaluation program,while the uncertainties form temperature,atmospheric pressure,volume and other parameters were evaluated by the class B.The combined relative standard uncertainty and expanded uncertainty were calculated in this research.The results showed that the mass concentration of indoor air TVOC was 0.4109 mg·m^(-3),and expanded uncertainty was 0.3626 mg·m^(-3)(k=2).The main uncertainty component came from the fitting of standard curve.