气袋采样-热脱附气相色谱-质谱联用法测定汽车内饰VOC散发量的不确定度评定

Uncertainty evaluation of VOC release quantity from vehicle interior parts by ATD/GC-MS with air bag sampling

采用气袋采样收集汽车内饰件中散发出来的VOC,使用热脱附气相色谱-质谱联用仪测试VOC含量,对测量结果的不确定度进行评定。通过对试验过程中样品采集、标准储备液、标准系列制备、曲线拟合等因素进行分析,计算了不确定度分量和合成不确定度。以甲苯为例,当汽车内饰件中甲苯散发量的测试结果为30.31μg/m^(3)时,扩展不确定度为4.21μg/m^(3);当测试结果约为30、150μg/m^(3)时,相对扩展不确定度分别为14%、8%(k=2)。曲线拟合引入的不确定度对测量结果的影响最大,通过使用高精度的采样泵和流量计,选用合适的量具规范标准系列制备的操作,减小分析仪器引入的不确定度等方法可降低测量结果的不确定度,提高检测的准确性。

Air bag sampling was used to collect VOC released from vehicle interior parts.The quantity of VOC was measured by ATD/GC-MS,and uncertainty of measurement results was evaluated.Through the analysis of sample collection,standard solution and its preparation process,curve fitting and other factors in the test process,the uncertainty component and synthesis uncertainty were calculated.Take toluene as an example,when the toluene release quantity from vehicle interior parts was 30.31μg/m^(3),the expanded uncertainty was 4.21μg/m^(3);when the test results were about 30,150μg/m^(3),the relative expanded uncertainty were 14%,8%(k=2),respectively.The experimental results showed that the uncertainty introduced by curve fitting had the greatest influence on the measurement results.By using high-precision sampling pump and flow meter,selecting appropriate measuring tools to regulate the operation of standard series preparation,and reducing the uncertainty brought by analytical instrument,the uncertainty of measurement results could be reduced and the accuracy of detection could be improved.