Lippa Katrice A, Duewer David L, Nelson Michael A, Davies Stephen R, Mackay Lindsey G
National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899-8392, USA.
National Measurement Institute, Australia, 105 Delhi Road, North Ryde, NSW 2113, Australia.
Accredit Qual Assur. 2019;24(6). doi: 10.1007/s00769-019-01407-6.
Metrological traceability for organic chemical measurements is a documented unbroken chain of calibrations with stated uncertainties that ideally link the measurement result for a sample to a primary calibrator in appropriate SI units (e.g., mass fraction). A comprehensive chemical purity determination of the organic calibrator is required to ensure a true assessment of this result. We explore the evolution of chemical purity capabilities across metrology institute members of the Consultative Committee for Amount of Substance: Metrology in Chemistry and Biology's Organic Analysis Working Group (OAWG). The OAWG work program has promoted the development of robust measurement capabilities, using indirect "mass balance" determinations via rigorous assessment of impurities and direct determination using quantitative nuclear magnetic resonance spectroscopy methods. A combination of mass balance and qNMR has been shown to provide a best practice approach. Awareness of the importance of the traceability of organic calibrators continues to grow across stakeholder groups, particularly in key areas such as clinical chemistry where activities related to the Joint Committee for Traceability in Laboratory Medicine have raised the profile of traceable calibrators.
有机化学测量的计量溯源性是一条具有规定不确定度的文件化校准不间断链，理想情况下，它将样品的测量结果与以适当国际单位制单位（例如质量分数）表示的一级校准物联系起来。需要对有机校准物进行全面的化学纯度测定，以确保对该结果进行真实评估。我们探讨了物质的量咨询委员会化学与生物学计量有机分析工作组（OAWG）计量机构成员化学纯度能力的发展情况。OAWG的工作计划通过对杂质的严格评估采用间接“质量平衡”测定法以及使用定量核磁共振光谱法进行直接测定，推动了强大测量能力的发展。质量平衡和定量核磁共振的结合已被证明是一种最佳实践方法。各利益相关方群体对有机校准物溯源性重要性的认识不断提高，特别是在临床化学等关键领域，与实验室医学溯源联合委员会相关的活动提高了可溯源校准物的知名度。
