National Institute of Metrology, P.R. China, Beijing, China.
Beijing University of Chemical Technology, Beijing, China.
Sci Rep. 2018 May 9;8(1):7390. doi: 10.1038/s41598-018-25682-4.
Primary methods play an important role in metrology. They can be used for the value assignment of certified reference materials, enabling the accuracy and comparability of the measurement. A novel potential primary method for enantiomer quantitation based on high-performance liquid chromatography-circular dichroism is described using L-phenylalanine as an example. The optimal quantitation range of L-Phe was from 0.1 mg/g to 1.2 mg/g, where both the relative bias and method variance were lower than 1%. The LOD and LOQ were 4 μg/g and 30 μg/g, respectively. The proposed method was also applied to the determination of the mass fraction of pure porcine insulin in solid. The average mass fraction obtained was 0.922 g/g with a RSD of 1.5%, and the associated relative uncertainty is 3.8% (k = 2), which agreed well with that obtained from the traditional isotope dilution mass spectrometry method. The LOD and LOQ for insulin quantitation were found to be 0.12 mg/g and 0.44 mg/g, respectively. The proposed method can be entirely described and understood by equations and a complete uncertainty statement can be defined in SI units.Therefore, it may be a potential primary method useful for the quantification of chiral compounds and proteins, and a supplementary method to the traditional isotope dilution mass spectrometry approach.
主要方法在计量学中起着重要作用。它们可用于赋值有证标准物质的值，从而确保测量的准确性和可比性。本文以 L-苯丙氨酸为例，描述了一种基于高效液相色谱-圆二色性的新型潜在的对映体定量的基准方法。L-Phe 的最佳定量范围为 0.1mg/g 至 1.2mg/g，此时相对偏差和方法方差均低于 1%。检测限和定量限分别为 4μg/g 和 30μg/g。该方法还应用于测定固体纯猪胰岛素的质量分数，得到的平均质量分数为 0.922g/g，相对标准偏差为 1.5%，相关相对不确定度为 3.8%（k=2），与传统同位素稀释质谱法所得结果吻合良好。胰岛素定量的检测限和定量限分别为 0.12mg/g 和 0.44mg/g。该方法可以通过方程完全描述和理解，并可以在 SI 单位中定义完整的不确定度声明。因此，它可能是一种有用的潜在基准方法，可用于手性化合物和蛋白质的定量，并且是传统同位素稀释质谱法的补充方法。
