Abstract：
To solve long-term lack of traceability of commercial calibrator kits and standardize clinical routine assays, we developed a human serum matrix-based unconjugated estriol (uE3) reference material (RM) with five concentration gradients. The RMs of uE3 were certified by the National Institute of Metrology (NIM) with the codes of GBW (E) 091048, GBW (E) 091049, GBW (E) 091050, GBW (E) 091051, and GBW (E) 091052. The RMs were determined by isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) reference method which was developed in our group and recommended by the Joint Committee on Traceability on Laboratory Medicine (JCTLM). GBW09224 is intended for use as a primary reference material to enable the SI-traceable measurement of uE3. This study describes the development process of these certified RMs. The candidate material was prepared by collecting from the remaining serum samples after routine clinical testing. Satisfactory homogeneity and stability were shown in these RMs. They are also commutable between the reference method and the three routine clinical immunoassay systems. To improve the accuracy of value assignment, a collaborative study in nine reference laboratories was conducted which was performed according to ISO/WD 15725-1 and all of the reference laboratories have been confirmed by China National Accreditation Service for Conformity Assessment (CNAS). The raw results were statistically analyzed and processed, coupled with uncertainty evaluation, to obtain the certified value: GBW (E) 091048 is 22.1 ± 1.3 nmol/L, GBW (E) 091049 is 33.6 ± 1.6 nmol/L, GBW (E) 091050 is 10.4 ± 0.8 nmol/L, GBW (E) 091051 is 15.5 ± 1.0 nmol/L, GBW (E) 091052 is 47.0 ± 2.0 nmol/L. The preparation process of human serum matrix-based reference material and the lack of these type of secondary (commutable) reference material of unconjugated estriol lead to the interruption of its traceability chain, which is a problem to be solved in its standardization as mentioned in the metrological traceability in ISO 17511, 2020.
摘要：
为了解决商业校准试剂盒缺乏可追溯性的长期问题，并规范临床常规检测，我们开发了具有五个浓度梯度的基于人血清基质的非结合雌三醇（uE3）参考材料（RM）。uE3的RM由国家计量研究所（NIM）认证，代码为GBW（E）091048，GBW（E）091049，GBW（E）091050，GBW（E）091051和GBW（E）091052。RM是通过同位素稀释液相色谱-串联质谱（ID-LC-MS/MS）参考方法确定的，该方法是我们小组开发的，并由实验室医学可追溯性联合委员会（JCTLM）推荐。GBW09224旨在用作主要参考材料，以实现uE3的SI可追溯测量。本研究描述了这些认证RM的开发过程。通过从常规临床测试后的剩余血清样品中收集候选材料来制备。在这些RM中显示了令人满意的均一性和稳定性。它们也可以在参考方法和三个常规临床免疫测定系统之间进行交换。为了提高值分配的准确性，在9个参考实验室中进行了一项合作研究，该研究是根据ISO/WD15725-1进行的，所有参考实验室均已得到中国合格评定国家认可委员会（CNAS）的确认。对原始结果进行统计分析和处理，加上不确定性评估，获得认证值：GBW(E)091048为22.1±1.3nmol/L，GBW(E)091049为33.6±1.6nmol/L,GBW(E)091050为10.4±0.8nmol/L,GBW(E)091051为15.5±1.0nmol/L,GBW(E)091052为47.0±2.0nmol/L。基于人血清基质的参考物质的制备过程以及这些类型的非结合雌三醇二级（可交换）参考物质的缺乏导致其可追溯链的中断，这是ISO17511，2020年计量可追溯性中提到的标准化需要解决的问题。
