Development of a fast method for simultaneous determination of hippuric acid, mandelic acid, and creatinine in urine by capillary zone electrophoresis using polymer multilayer-coated capillary.

Abstract

This paper reports the development of a fast separation method employing capillary zone electrophoresis for the simultaneous determination of hippuric acid, mandelic acid, and creatinine in samples of urine using a coated capillary. The background electrolyte was composed of 10mmolL-1 tris(hydroxymethyl)aminomethane and 30mmolL-1 2-hydroxy-isobutyric acid at pH3.6. The internal standard was 3,5-dihydroxybenzoic acid. Separations were performed in a fused silica capillary (32cm total length, 8.5cm effective length, and 50μm internal diameter) coated with crosslinked hydroxypropyltrimethyl ammonium chloride chitosan and κ-carrageenan. Direct UV detection was performed at a wavelength of 200nm. Samples and standards were injected hydrodynamically (-50mbar, 3s) using the short-end injection procedure. The electrophoretic system was operated under constant voltage of 30kV with positive polarity on the injection side. The separation time for hippuric acid, mandelic acid, and creatinine was less than 70s. The evaluation of some analytical parameters of the method for the three analytes showed good linearity (R 2 > 0.99), limit of detections of 0.21 to 0.63mgL-1, inter-day precision better than 3.0% (peak area), and recovery in the range of 98 to 106%. The method developed was applied in the analysis of the three analytes in urine samples. Graphical Abstract New method using capillary zone electrophoresis for analysis of creatinine, hippuric acid and mandelic acid in urine.