Determination of organic acids in urine by capillary zone electrophoresis

The simultaneous measurement of organic acids was studied using capillary electrophoresis with direct measurement of UV absorption at 185 nm. The organic acids studied were oxalic, formic, malonic, fumaric, succinic, alpha-ketoglutaric, citric, acetic, pyruvic, lactic, isovaleric and hippuric acid. They were separated in a fused-silica capillary (100 cm x 75 microm I.D.) filled with 50 mM borax buffer (pH 10.0) containing cationic surfactant as the electroosmotic flow modifier. The method was successfully applied to the determination of organic acids in urine in comparison with an organic acid analyser.