Division of Biological, Energy and Environmental Measurement, National Institute of Metrology, Beijing, China.
Anal Bioanal Chem. 2011 Jul;400(10):3443-9. doi: 10.1007/s00216-011-4994-3. Epub 2011 Apr 21.
We present the development process for National Institute of Metrology (NIM) bovine serum albumin (BSA) certified reference material (CRM). Each CRM unit contains about 200 mg of purified BSA. The moisture, ignition residue, molecular weight, and high-performance liquid chromatography (HPLC) purity were analyzed and mass spectrometry based protein identification was carried out to ensure the material was BSA. Both amino acid based isotope dilution mass spectrometry (IDMS) and a purity deduction method were selected for value assignment. The certified value was the average of the IDMS and the purity deduction result. HPLC purity analysis was used to examine the homogeneity and stability of solid BSA CRM. Fifteen units were selected for between-bottle homogeneity examination and seven subsamples from the same bottle were selected for within-bottle homogeneity examination. Statistics showed the CRM passed both the between-bottle and the within-bottle homogeneity examination. The CRM stability under storage conditions (-20 °C) was tested for 18 months and no trend was observed. Uncertainties from the balance, amino acid purity, hydrolysis, method reproducibility, homogeneity, and stability were taken into account in uncertainty evaluation. The final certified value of NIM BSA CRM is (0.963±0.038) g/g.
我们介绍了中国计量科学研究院牛血清白蛋白（BSA）有证标准物质（CRM）的研制过程。每个 CRM 单元包含约 200mg 纯化的 BSA。对水分、灼烧残渣、分子量和高效液相色谱（HPLC）纯度进行了分析，并进行了基于质谱的蛋白质鉴定，以确保该物质为 BSA。同时选择了基于氨基酸的同位素稀释质谱（IDMS）和纯度扣除法进行赋值。认证值为 IDMS 和纯度扣除结果的平均值。HPLC 纯度分析用于检查 BSA CRM 固体的均一性和稳定性。选择了 15 个单元进行瓶间均一性检查，从同一瓶中选择了 7 个亚样本进行瓶内均一性检查。统计结果表明，CRM 通过了瓶间和瓶内均一性检查。在储存条件（-20°C）下对 CRM 的稳定性进行了 18 个月的测试，未观察到趋势。在不确定度评估中考虑了来自天平、氨基酸纯度、水解、方法重现性、均一性和稳定性的不确定度。中国计量科学研究院 BSA CRM 的最终认证值为（0.963±0.038）g/g。
