Electrophoretic separations were performed in a capillary formed by connecting a 9.7 cm long separation capillary with an inner diameter 25 µm and an auxiliary 22.9 cm long capillary with inner diameter 100 µm. A coupled capillary was tested for electrophoretic separation at high electric field and in the short-end injection mode with diode-array detection for determination of creatinine and uric acid in human urine samples.
The developed methods are characterized by a separation time around 10 s and limits of detection 2.4 mg.L-1 for creatinine and 0.9 mg.L-1 for uric acid.