Labile hemoglobin A1c (also known as pre-HbA1c or LA1c or pre-glycohemoglobin) an unstable form, is a Schiff base formed during non-enzymatic glycation of hemoglobin. The concentration of labile fraction varies with acute change in plasma glucose level. Labile hemoglobin A1c fraction cannot be separated from the stable ketoamine fraction by most of the methods available for estimation of glycated hemoglobin (HbA1c). Though ion-exchange HPLC (high pressure liquid chromatography) method can separate the labile HbA1c fraction, but in some situation abnormally high level of this fraction may serve as a pre-analytical error interfering in estimation of glycated hemoglobin. By focusing on the hemoglobin chromatogram, reporting of this pre-analytical error can be minimized in HPLC method.