CAPILLARY ELECTROPHORESIS AS A CLINICAL TOOL - DETERMINATION OF ORGANIC-ANIONS IN NORMAL AND UREMIC SERUM USING PHOTODIODE-ARRAY DETECTION

We report the use of free solution capillary electrophoresis to identi fy and quantify low-molecular-mass compounds found in normal and uremi c serum as well as in hemodialysate fluid. The method reported provide s a multicomponent analysis, allowing a single-step screening for more than 19 metabolites in less than 16 min, Serum samples from healthy i ndividuals and from patients who have been diagnosed with chronic rena l failure are analyzed using a berate buffer system at pH 9.0, and an extended light path capillary. Several ionic sample constituents are i dentified by electrophoretic mobility, UV spectra, and spiking with au thentic standards. An analysis of the relative concentration of severa l metabolites, including hypoxanthine, pseudouridine, hippuric acid, a nd uric acid is presented. Each of these four metabolites is found in both normal and uremic serum samples (limits of detection 1 to 6 mu M) . Moreover, each of these metabolites is present at significantly elev ated levels in uremic patients. The method reported is shown to have p romising clinical utility for profiling-serum sample constituents, and for quantitative determination of a few important metabolites.