Which stationary phase is used for the measurement of hemoglobin A1c by high performance liquid chromatography?

The measurement of hemoglobin A1c by high-performance liquid chromatography (HPLC) typically utilizes a cation exchanger as the stationary phase. This is because hemoglobin A1c is a glycosylated form of hemoglobin that carries a net positive charge at physiological pH, therefore a cation exchanger is ideal for separating it from other forms of hemoglobin.

In HPLC for hemoglobin A1c analysis, the cation exchange chromatography takes advantage of the differences in charge between the various hemoglobin species. The cation exchanger has functional groups that attract cations, allowing for effective separation based on charge differences. As the sample is passed through the column, hemoglobin A1c will interact with the cationic sites and elute at a different time compared to other types of hemoglobin that may not bind as strongly or may elute sooner.

This method provides high specificity and sensitivity for hemoglobin A1c measurement, making it a standard practice in clinical laboratories for monitoring long-term glycemic control in diabetic patients.