A method for measuring hydroxylysine and glycosylated hydroxylysines in urine and protein hydrolysates

A method for measuring hydroxylysine and glycosylated hydroxylysines is described, based on the separation of the 3 compounds by ion-exchange chromatography, followed by spectrophotometric analysis of the hydroxylysine present as glucosylgalactosylhydroxylysine, galactosylhydroxylysine and free hydroxylysine. The method does not require prior preparation of the urine sample nor the use of high-resolution ion-exchange systems. The method is applicable to the determination of the glycosylated hydroxylysine and hydroxylysine content of urine or alkaline hydrolysates of proteins.