气相色谱法测定稳定同位素^13(C)标记辛酸纯度的不确定度评定

Evaluation of Uncertainty in the Determination of Purity of Stable Isotope^13(C)Labelled Octanoic Acid by Gas Chromatography

根据行业标准《稳定同位素^13(C)标记的辛酸》(HG/T 5941—2021),采用气相色谱法测定稳定同位素^13(C)标记的辛酸纯度,对测定过程中的不确定度来源进行了分析,主要为标准溶液配制、标准曲线拟合、样品制备和样品测量重复性等。按《测定不确定度评定与表示》(JJF 1059.1—2012)的规定进行不确定度计算,稳定同位素^13(C)标记的辛酸纯度的测量不确定度来源主要为标准溶液配制与标准曲线拟合,其合成标准不确定度为0.817%,扩展不确定度为1.6%,测定结果为99.0%±1.6%(k=2)。

According to the industry standard Stable isotope^13(C)labelled Octanoic acid(HG/T 5941—2021),the purity of octanoic acid labeled with stable isotope^13(C)is determined by gas chromatography,and the sources of uncertainty in the determination process are analyzed,mainly including standard solution preparation,standard curve fitting,sample preparation and sample measurement repeatability.The uncertainty is calculated according to the provisions of Evaluation and Expression of Uncertainty in Measurement(JJF 1059.1—2012).The source of uncertainty in the measurement of octanoic acid purity labelled with stable isotope^13(C)is mainly the preparation of standard solution and the fitting of standard curve.The combined standard uncertainty is 0.817%,the expanded uncertainty is 1.6%,and the measurement result is 99.0%±1.6%(k=2).