Reversed-phase liquid-chromatographic analysis of hemodialysate from uremic patients.

With reversed-phase high-performance liquid chromatography we effected rapid and efficient separation of metabolites present in hemodialysate fluid from uremic patients on the artificial kidney. With an aqueous sodium acetate/methanol gradient as mobile phase, more than 50 ultraviolet-absorbing constituents were resolved in a 70-min chromatogram of a 100-mul sample of dialysate. Many of the metabolites could be detected in concentrations below 0.1 mg/liter. From results of ultraviolet spectrophotometric analysis and the gas- and liquid-chromatographic properties of standards, half the observed chromatographic peaks have been characterized or identified. The method has been shown to be more than 10-fold faster than comparable separations by ion-exchange techniques.