罐采样/预浓缩-GC/MS法测定环境空气中7种苯系物的不确定度评定  

Uncertainty evaluation for determination of 7 BTEX in ambientair by canister sampling/preconcentration-GC/MS method

作　　者：王丽敏 徐洪伟 于秀彦 王静云 张站朝 WANG Limin;XU Hongwei;YU Xiuyan;WANG Jingyun;ZHANG Zhanchao(Weihai Ecological Environment Monitoring Center of Shandong Province,Weihai Shandong 264200;Yantai Ecological Environment Monitoring Center of Shandong Province,Yantai Shandong 264010;Jinan Ecological Environment Monitoring Center of Shandong Province,Jinan Shandong 250102)

机构地区：[1]山东省威海生态环境监测中心,山东威海264200 [2]山东省烟台生态环境监测中心,山东烟台264010 [3]山东省济南生态环境监测中心,山东济南250102

出　　处：《首都师范大学学报（自然科学版）》2023年第5期62-68,共7页Journal of Capital Normal University：Natural Science Edition

基　　金：济南市科技局社会民生专项项目(201807008);山东省环境科学学会基金项目(202208,202102)。

摘　　要：为了建立罐采样/预浓缩-气相色谱质谱法(GC/MS)测定空气中7种苯系物(BTEX)的不确定度评定方法,本文根据监测方法和计算公式,拟建立不确定度数学模型,分析其测定过程中不确定度的来源。文中涉及到的测量不确定度主要来源包括标准气体配置、校准曲线拟合、仪器测量、重复性测量、样品稀释和相对分子质量等。对各测量不确定度分量的计算和评定结果显示不确定度引入由高到低的排序为:标准气体配置、仪器测量、标准曲线拟合、重复性测量、样品稀释和相对分子质量。当环境空气中7种BTEX的质量浓度水平在56.8~145.2μg/m^(3),置信区间为95.0%,包含因子为2时,测定结果的扩展不确定度为4.0~10.4μg/m^(3)。In order to establish an uncertainty evaluation method for the determination of seven benzene series(BTEX)in air by canister sampling/prethickening-gas chromatography/mass spectrometry(GC/MS),a mathematical model of uncertainty was proposed to analyze the sources of uncertainty in the determination process according to the monitoring method and calculation formula.The main sources of uncertainty included standard gas configuration,calibration curve fitting,instrument measurement,repeatability measurement,sample dilution and relative molecular mass.The uncertainty components were calculated and evaluated.The evaluation results showed that the uncertainty was ranked from high to low as standard gas configuration,instrument measurement,standard curve fitting,repeatability measurement,sample dilution and relative molecular mass.When the concentration levels of 7 BTEX in ambient air range from 56.8 to 145.2μg/m^(3) and confidence interval is 95.0%,the inclusion factor is 2,and the extended uncertainty of the determination results is 4.0 to 10.4μg/m^(3).

关 键 词：苯系物 不确定度 GC/MS 预浓缩 环境空气 

分 类 号：X830.2[环境科学与工程—环境工程] O652[理学—分析化学]