Ion-pair reversed-phase HPLC determination of creatinine in urine

A high performance liquid chromatography (HPLC) with isocratic ion-pair-rev ersed-phase separation and UV detection at 230 nm is proposed for the deter mination of creatinine in urine. The analysis is achieved on a C-18-Symmetr y column (4 mu m, 150mm x 3.9mm ID) using a mixture of 10 mM phosphate buff er pH=4, containing 3mM 1-octane-sulfonic acid, sodium salt and methanol (9 7:3). A flow-rate of 0.5mL/min and a column temperature of 30 degrees C wer e employed. We validated the method for linearity, precision, and accuracy and the results were found to be excellent. The procedure proposed here is an alternative to less specific colorimetric methods.