Determination of creatinine in human, dog and rat urine by high-performance liquid chromatography on a column of hydroxymethylated porous polystyrene

Abstract

Creatinine in urine is commonly determined by assay methods based on the Jaffi!. reaction [l] in which creatinine reacts with alkaline picrate to form an amber-yellow colour. This reaction, however, is non-specific and many compounds are known to react with picrate [ 21. Preliminary purification by ion-exchange chromatography has been attempted to overcome these difficulties [3-51. More specific enzymatic methods have also been used [6]. Recently, high-performance liquid chromatography (HPLC) using a reversedphase column was introduced for the determination of creatinine in human urine and plasma [ 7-131. These HPLC separations are fast, reliable and require minimal work-up. However, a method for the determination of creatinine in urine of experimental animals such as dog and rat has not been reported. In this paper we describe a method for measuring creatinine in human, dog and rat urine by HPLC on a column of hydroxymethylated porous polystyrene which is chemically more stable than the regular reversed-phase column.