Glycated hemoglobins (GHb) are composed of A
1a, A
1b, labile-A
1c (1-A
1c), stable-A
1c (s-A
1c) and others. The concentration of s-A
1c can be used as an index of the average blood glucose value for the preceding 2 months. Therefore, determination of s-A
1c is useful for the assessment of long-term control of diabetes mellitus. A rapid analysis method of s-A
1c by HPLC was discussed. Packings with 5 μm and 3.5 μm diameter polymethacrylate gel modified with carboxymethyl groups, were prepared, and a correlation between particle diameter of the packings and chromatographic performances, such as number of theoretical plates (
N), retention time (
tR), pressure drop (Δ
P) were studied. N increased as the particle diameter of packings was decreased. The
N for s-A
1c by linear gradient elution was 2× 10
3 plates for 3.5 μm diameter packing, which was five times larger than that of 5 μm diameter packings. Using 3.5 μm packings, s-A
1c was well separated from 1-A
1c by the optimization of analytical conditions, such as the concen-tration of the initial eluent. Using the column (4.6 mm i.d. × 35 mm) packed with 3.5 μm packings, six hemoglobin components, A
1a, A
1b, HbF, 1-A
1c, s-A
1c and A
0, were separated in a 3.5 min cycle by three step gradient elution, thereby reducing analysis time.
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