A revised method for determination of serum mercaptalbumin and non-mercaptalbumin by high-performance liquid chromatography coupled with postcolumn bromocresol green reaction

Background Previously, high-performance liquid chromatography (HPLC) equipped with ultraviolet or fluorescence detectors has been used for separation of human mercaptalbumin (HMA) and human non-mercaptalbumin (HNA). However, it is difficult to perform reliable chromatographic analysis due to peak interference of such serum compounds as uric acid and bilirubin. The aim of this study is to explore a selective and simple analytical method for the determination of HMA and HNA. Method HMA and HNA in serum sample were separated by HPLC and reacted with bromocresol green using a postcolumn reaction scheme. Results A complete separation of HMA and HNA is achieved in less than 30min by using weak anion exchange columns and isocratic elution. Within-run and between-day precisions at albumin concentration of 45g/L were 4.2 and 1.7% for HMA and 4.5 and 4.6% for HNA, respectively. There was no interference in HMA and HNA peaks when bilirubin-, haemoglobin- or chyle-spiked pooled serum samples were analysed. Conclusion Our method is reliable and not labour-intensive and, therefore, might be applicable for clinical and epidemiological studies.