Determination of estriol and creatinine in urine by high performance liquid chromatography

A quantitative method for the determination of estriol (E3) and creatinine (C) in random urine by high performance liquid chromatography is described. The mobile phase was a mixed solution of methanol and phosphate buffer (0.025 M, pH 6.5) and the detection wavelength was at 205 nm. The method was simple, rapid and accurate. The OCV for E3 and C using this method were 1.7-3.4% and 2.2-2.5%, respectively. The RCV for E3 and C were 6.2-7.0% and 4.5-6.9%, respectively. The recoveries were 87-104% for E3 and 98-103% for C, respectively. The method has been used for clinical determinations.