Rapid determination of creatinine in urine by high performance capillary zone electrophoresis

Objective To establish a method for the determination of creatinine in urine by capillary zone electrophoresis. Methods 48.5 cm×50 μm uncoated capillary, phosphoric acid buffer (0.1 mmol/L, pH2.5) and UV-detector at 191 nm wavelength were used in this method. Results The calibration curve showed a good linearity for creatinine in the concentration range of 34.5-8 840 μmol/L (r=0.998). Within-day CV and between-day CV for assaying the urine samples of creatinine were 3.5% and 6.2% respectively. The average recovery was 94.7%. We also compared the method with the Jaffe kinetic methed, and the results showed a satisfactory correlation (r= 0.998,n=45). Conclusions The method is simple, rapid and with wide linearity range, so it is useful for clinical application.