Flow injection analysis of uric acid with a uricase- and horseradish peroxidase-coupled Sepharose column based luminol chemiluminescence system

Abstract

The flow-injection analysis of uric acid was developed based on the enhanced effect of horseradish peroxidase (HRP) on the luminol–hydrogen peroxide chemiluminescence (CL) system. With the assistance of uricase and HRP-coupled Sepharose columns, a detection limit of 5.0×10 −8 M (1.5 μg l −1) and a dynamic range of 5.0×10 −8 to 2.5×10 −4 M can be obtained. A repetitive injection of 1.0×10 −5 M uric acid solutions gave satisfactory reproducibility with a relative standard deviation of 2.14% ( n=20). Possible interferences from major bioactive molecules in human fluids and other related compounds were studied. Uric acid in a standard serum sample and a urine sample was analyzed. The uric acid content of a standard reference serum sample obtained from the developed CL analysis agrees well with the certified value and recoveries of 95.4 to 105.4% were obtained for spiking the standard uric acid to the urine samples. The feasibility of the developed method for uric acid analysis in human fluids was confirmed.