The IFCC Reference System is based on the concept of metrological traceability (Figure). In the traceability chain, primary calibrators consisting of mixtures of pure HbA1c and HbA0 are used to calibrate the IFCC Reference Measurement Procedure. In the analytical process enzymatic cleavage of the hemoglobin (of both, the primary calibrators and the secondary calibrators to which values have to be assigned) results in hexapeptides that are quantified with either HPLC-Mass Spectrometry or HPLC-Capillary Electrophoresis. For details see the reference.
Jeppsson JO, Kobold U, Barr J, Finke A, Hoelzel W, Hoshino T, Miedema K, Mosca A, Mauri P, Paroni R, Thienpont L, Umemoto M, Weykamp C. International Federation of Clinical Chemistry and Laboratory Medicine. Approved IFCC reference method for the measurement of HbA1c in human blood. Clin Chem Lab Med 2002;40:78-89.