Evaluation of a Colorimetric Method in Glycated Hemoglobin measurment

Measuring of hemoglobin A1c(HbA1c)as the main glycated hemoglobin in circulation, is the most reliable method for evaluation of hyperglycemia control in diabetic patients. Colorimetric measuring method for HbA1c is based on releasing glucose in 100°C as5-hydroxymethylfurfural(5HMF)and then measuring it in a colorimetric reaction with thiobarbituric acid (TBA).This method is affected by different variables. This study shows that TBA solution is stable at 4°c at least for one month. But by reducing the time of boiling from 5 hours to 1 hour, color intensity would decrease as much as 42%. On the other hand, reducing the time and temperature of colorimetric reaction from 40 to 15 minutes and 50 ° C to 25° C would result in 29% and 63% reduction in color intensity, respectively. In addition, developed color is unstable at room temprature and would decerase as much as 53% within 40 minutes. With the colorimetric measurment of HbA1c, it is recommended to use 5 hours boiling, colorimetric reaction in 50 ° C for 40 minutes,and rapid reading of optical density.