An assay of creatine in human serum using an HPLC with UV detection

Abstract

An ion-exchange high-performance liquid chromatography with ultraviolet detection for the determination of creatine in human serum has been developed. The human serum was deproteinized with perchloric acid. For the separation, a cation-exchange column LC-SCX, 250 mm × 4.6 mm, 5 μm, was used. The mixture of ethanol and 10 mmol l–1 ammonium acetate (15:85, v/v), pH 4.00 ± 0.05 was used as a mobile phase. The analytical performance of this method is satisfactory: the intra-assay and inter-assay coefficients of variation were below 10 %. Quantitative recoveries of spiked serum samples were between 97.1 % and 103.5 %. The calibration curve was linear in the whole range tested. The limit of quantification was 2 μmol l–1. The preliminary reference ranges of serum creatine in a group of blood donors are 17-89 μmol l–1 for women and 21-97 μmol l–1 for men.