Determination of uremic toxins in biofluids: creatinine, creatine, uric acid and xanthines.

Rapid and accurate determination of small molecule metabolic end-products is vital for clinical diagnosis and study of many metabolic disorders and medical abnormalities. Chromatographic and electrophoretic techniques are attractive for clinical analyses because of the inherent ability to analyze multiple component biofluids and determine the analytes of interest with minimal interference from other species. This manuscript reviews recent (1990-present) developments in chromatography and electrophoresis methodology for the determination of creatinine, creatine, uric acid and xanthines in biofluids.