Comparability of measurement results and their metrological traceability to the International System of Units (SI) are fundamental tools to ensure reliable decisions in the social sphere, commerce, and science. The use of appropriate references in analytical chemistry, such as certified reference materials (CRMs) of high purity substances, is one of the required procedures to obtain traceable measurements. When commercial standards with non-certified purity values are used, traceability must be achieved by determining the purity of the standard using a potential primary reference measurement procedure or other appropriate methods. Quantitative nuclear magnetic resonance (qNMR) is a technique with the potential to be used in primary measurement procedures. This work presents the determination of purity by ¹H qNMR for nitrofuran metabolites 3-amino-2-oxazolidinone (AOZ), 3-amino-5-morpholinomethyl-2-oxazolidinone (AMOZ), and 1-aminohydantoin (AHD). Furthermore, a recent qNMR method developed by our group to improve the quantitative performance of measurements using ¹³C nucleus was used to determine the purity of semicarbazide (SEM) nitrofuran metabolite. Purity values obtained by qNMR for AOZ, AMOZ, and AHD standards were compared to values obtained by the mass balance approach using a suite of analytical methods: Karl Fischer (KF) coulometric titration and thermogravimetry (TG) for the determination of water and residual solvents, gas and liquid chromatography for the determination of impurities structurally related to the metabolites. The results obtained by qNMR and mass balance were consistent.

Graphical abstract

测量结果的可比性及其与国际单位制（SI）的计量可追溯性是确保在社会，商业和科学领域做出可靠决策的基本工具。在分析化学中使用适当的参考物质，例如高纯度物质的认证参考物质（CRM），是获得可追溯测量值的必要步骤之一。当使用具有未经认证的纯度值的商业标准品时，必须通过使用潜在的主要参考测量程序或其他适当的方法确定标准品的纯度来实现可追溯性。定量核磁共振（qNMR）是一种有可能在主要测量程序中使用的技术。这项工作提出了¹的纯度测定硝基呋喃代谢物3-氨基-2-恶唑烷酮（AOZ），3-氨基-5-吗啉代甲基-2-恶唑烷酮（AMOZ）和1-氨基乙内酰脲（AHD）的HqNMR。此外，我们小组开发的一种最新的qNMR方法，用于改进使用¹³ C核的测量的定量性能，用于测定氨基脲（SEM）硝基呋喃代谢物的纯度。使用一整套分析方法，将通过qNMR获得的AOZ，AMOZ和AHD标准品的纯度值与通过质量平衡法获得的值进行比较：卡尔·费休（KF）库仑滴定法和热重分析法（TG），用于测定水和残留溶剂，气相和液相色谱法测定与代谢物结构相关的杂质。通过qNMR和质量平衡获得的结果是一致的。

图形概要