环境监测用氮气中多组分VOCs标准物质的研制

Development on Reference Material of Multi-Component VOCs in Nitrogen Gas for Environmental Monitoring

介绍了采用称量法制备瓶装1μmol/mol氮气中42个组分挥发性有机物(VOCs)标准物质的研制方法。建立了选择离子模式,气相色谱-质谱联用的分析方法,对目标组分在气瓶中的长期稳定性进行了考察。所选择的42种目标组分完全满足中国环境保护标准《环境空气挥发性有机物的测定吸附管采样-热脱附/气相色谱-质谱法》(HJ 644—2013)和美国环保署《使用特殊处理的采样罐/气相色谱仪检测环境大气中的挥发性有机物》(EPA TO—14A)这2个方法标准中所规定的环境空气中挥发性有机有害成分的监测要求。将研制的气体标准物质与中国计量科学研究院(NIM)和英国国家物理实验室(NPL)分别进行了比对测试,取得了良好的比对结果与国际等效度。结果表明,1μmol/mol氮气中42种组分VOCs标准物质的有效期为一年,相对扩展不确定度为5.0%(包含因子k=2),并取得国家标准物质证书GBW(E)062231。

The development of multi-component VOCs reference material in nitrogen gas at 1 μmol/mol level by gravimetric preparation method was described in this paper. The stability of target analytes in cylinder was checked using GC coupled with a quadruple mass selective detector. All the selected 42 target analytes could meet the requirements on monitoring VOCs in ambient air, according to the China environmental protection method HJ 644-2013 and the U.S. Environmental Protection Agency method TO-14 A. The validation result between NIM and NIMTT showed a reliable consistency, and an international equivalence degree was also obtained from the comparison result between NPL and NIMTT. All the research results indicated that an estimated relative expanded uncertainty of 5.0%(k=2) and one year shelf life has been achieved. This gas reference material has acquired the certificate of national secondary gas reference material GBW(E)062231.