Determination of uric acid and p-aminohippuric acid in human saliva and urine using capillary electrophoresis with electrochemical detection

The monitoring of uric acid (UA) and p-aminohippuric acid (PAH) levels in biological samples is routinely carried out in clinical laboratories as an indication of renal disease. With the aim of investigation of the correlation between the trace amounts of UA and PAH in human saliva or urine and renal diseases, we carried out the determination of UA and PAH in human saliva and urine by using capillary electrophoresis with electrochemical detection (CE-ED) in this work. Under the optimum conditions, UA, PAH and three coexisting analytes could be well separated within 21 min at the separation voltage of 14 kV in 80 mmol/L borax running buffer (pH 9.2). Good linear relationship was established between peak current and concentration of analytes over two orders of magnitude with detection limits (S/N = 3) ranged from 5.01 × 10−7 to 2.00 × 10−6 mol/L for all analytes. The result shows that this proposed method could be successfully applied for the study on the correlation between the levels of UA and PAH in human saliva and urine and renal diseases, and provide an alternative and convenient method for the fast diagnosis of renal disease.