顶空气相色谱内标工作曲线法测定血液中乙醇的不确定度评估

Evaluation of the Uncertainty in Determining Blood Alcohol Concentration with Headspace Gas Chromatography Internal Standard Working Curve Method

目的开展血液中乙醇检测结果的不确定度评定,以报告更客观准确的检测结果。方法按顶空气相色谱内标工作曲线法和相关数学模型进行不确定度的评定。结果取样引起的不确定度为0.11%,标准品及内标物纯度引起的不确定度为0.15%,体积引起的不确定度为1.3%,工作曲线(线性回归)引起的不确定度为1.6%,测量重复性引起的不确定度为1.1%,血液中乙醇的扩展不确定度为4.7%(包含因子K=2)。结论影响顶空气相色谱内标工作曲线法测定血液中乙醇的不确定度的因素主要是测量重复性、工作曲线和体积。

[ Objective ] To evaluate the uncertainty in determining blood alcohol concentration with headspace gas chromatography internal standard working curve method in order to report more objective and accurate detection result. [ Methods] Gas chromatography internal standard working curve method and relevant mathematic models were used to conduct the uncertainty evaluation. [ Results] The uncertainties brought from sampling, purity of standard and internal standard, volume, working curve and measurement repeatability were 0.11%, 0. 15 %, 1.3 %, 1.6 % and 1.1% respectively; the expanded uncertainty of ethanol in blood was 4.7%. [ Conclusion] The major factors that influence the uncertainty of determining ethanol in blood with headspace gas chromatography internal standard working curve method are measurement repeatability, working curve and volume.