Estimation of serum uric acid by high performance liquid chromatography with electrochemical detection

A precise method for serum uric acid is described based on direct electrochemical oxidation in the eluate from high performance liquid chromatography. The detection limit for uric acid was found to be approximately 1 pg and accurate measurements were possible at the 100 pg level. Detailed procedures are outlined for 0.5 ml and 25 mul serum samples, the relative standard deviations being 1.7% and 1.8%, respectively, for a 6.2 ml/dl serum pool. Samples were normally deproteinized, however, the analysis can be carried out by injection of 2 mul of serum diluted 10-fold with distilled water. The proposed micro method is highly selective and eliminates the need for the enzyme preparation and/or nonspecific colorimetric reagents in common use.