工作场所空气中环氧丙烷热解吸气相色谱法测定的不确定度评定

目的建立工作场所空气中环氧丙烷热解吸气相色谱法测定的不确定度评定方法,通过控制这些因素提高检测结果的置信度和准确性。方法依据中华人民共和国国家计量技术规范JJF 1059-1999《测量不确定度评定与表示》进行评定。结果环氧丙烷不确定度主要来源:①标准状态下采样体积V0不确定度;②标准气体配制过程引入的不确定度;③工作曲线绘制方法引入的不确定度;④样品测定重复性引入的不确定度。取置信概率为95%,包含因子k=2,则其扩展不确定度:U=2×5.79%=11.58%。结论该不确定度评定方法对环氧丙烷的热解吸气相色谱法检测过程的质量控制意义十分重大,可以提高检测结果的准确性和置信度。

Uncertainty Evaluation on Determination of Propylene Oxide in Air of Work Places by Thermal Desorption Gas Chromatography

Objective]To establish the evaluation method of uncertainty in determination of propylene oxide in air of work places by thermal desorption gas chromatography,improve the confidence and accuracy of the test results by controlling these factors.Methods]The Evaluation and expression of uncertainty in measurement（JJF 1059-1999） from national metrology technical specifications was applied to evaluate.Results]The main sources of uncertainty of propylene oxide included： ①The uncertainty caused by sampling volume under standard conditions V0,② The uncertainty caused by preparing process of the standard gas preparation,③The uncertainty caused by drawing method of the standard curve,④The uncertainty caused by repeatability of determination.While confidence probability was 95% and coverage factor k=2,the expanded uncertainty was U=2×5.79%=11.58%.Conclusion]The uncertainty evaluation method has great significance in quality control of determination of propylene oxide by thermal desorption gas chromatography,and can improve the accuracy and confidence of test results.