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HbA1c is an accepted blood glucose index used for evaluating metabolic control in diabetes mellitus. HbA1c sampling at home makes it easier to continually keep track of the metabolic control for both the diabetic patient and the physician. Sampling and sample handling is at the same time simplified for wards and laboratory. The method has economic benefits for the health care system and community.

The Pharmacia Mono S column for glycated haemoglobin (HbA1c) was compared with Mono S HR 5/5 and three other cation exchange columns to optimize analysis of HbA1c. This column allows a significant decrease in separation time, resulting in a sample throughput of 12 samples per hour. The choice of parameters for integration of peak areas in the chromatograms is very important for reproducible results. Since pure calibrators of HbA1c are not available, the relative contribution of HbA1c to the total amount of haemoglobin is calculated. We have compared valley-to-valley integration with baseline integration to assess reproducibility. Valley-to-valley integration significantly enhances the reproducibility of the method and is therefore preferable for routine analyses of HbA1c.

A simple and practical method of sampling capillary blood was tested. This method was used for determination of glycated haemoglobin by ion exchange chromatography. Capillary blood was collected onto filter paper and placed in a small polypropylene tube containing phosphate-buffered sodium chloride with EDTA and p-hydroxybenzoic acid methyl ester. There was good correlation between filter paper sampling and conventional sampling in tubes with EDTA as anticoagulant. With this new sampling technique the glycated haemoglobin value was stable for 7 days at room temperature and for at least 10 days at +4 degrees C. Sampling can be performed by the patient at home and the sample then mailed to the laboratory, thus enabling analysis to be performed prior to the patient's visit to the physician.