Development of Mobile-Phase Buffers and Evaluation of Analytical Performance for HbA_1c Assays

Hemoglobin A_1c (HbA_1c) plays a role in the diagnosis and assessment of glycemic control in patients with diabetes. However, few studies have focused on the preparation methods and analytical performance evaluation of different formulations of mobile-phase buffers for HbA_1c assays. In this study, mobile-phase buffers of new formulations were prepared for the measurement of HbA_1c. Following the Clinical and Laboratory Standards Institute (CLSI) guidelines, the analytical performance of newly developed mobile-phase buffers was evaluated. The CVs of the intra- and inter-assay precision were less than 0.94%, the RDs of accuracy were less than ± 3.00%, and the carryover was 0.00%. The measured HbA_1c values were linear from 4.50% to 16.80% (26.00-160.00 mmol/mol). A comparison of newly developed and commercial mobile-phase buffers revealed that the Pearson regression equation was Y = 0.9862x + 0.0888 (R² = 0.9990), and the Bland-Altman mean difference between the two mobile-phase buffers was -0.02833% (95% CI: -0.1853% to 0.1278%). The chromatography column had a lifetime of over 7000 tests. The reference interval was 4.30%-6.30% (23.00-45.00 mmol/mol). Stability was acceptable within 24 months. The newly developed mobile-phase buffers demonstrated good analytical performance (i.e., precision, linearity, accuracy, carryover, reference interval, the number of chromatography column runs, and stability).