A simple, rapid and reliable high performance liquid chromatography method for the simultaneous determination of creatinine and uric acid in plasma and urine

A simple, rapid and reliable method for the simultaneous determination of creatinine (Cr) and uric acid (UA) in plasma and urine has been developed using high performance liquid chromatography with ultraviolet detection. Separation was achieved by an Agilent ZORBAX SB-C18 column and an optimized mobile phase consisting of 20 mmol L-1 sodium acetate, 30 mmol L-1 acetic acid and 1% methanol. The total time of analysis was 4 min. Good linear responses were found with correlation coefficient (r) > 0.999 for both Cr and UA within the concentration range of relevant levels. The recoveries of Cr and UA were 102 +/- 1% and 99.3 +/- 2.1% for plasma; and 100 +/- 2% and 102 +/- 4% for urine. CVs of repeatability and intermediate precision of all analytes were less than 5%. The limit of detection of the developed method was: Cr, 0.09 mu mol L-1 and UA, 0.04 mu mol L-1. The proposed HPLC method could be used for not only reference purpose but also routinely in clinical laboratory testing.