Creatinine determined by "high-performance" liquid chromatography.

We describe a "high-performance" liquid-chromatographic procedure for determination of creatinine in serum. Creatinine is separated from other species by cation-exchange chromatography. Absorbance of the creatinine in the eluate is monitored at 234 nm. Results from this procedure on sera correspond closely to those of a manual Jaffé-reaction procedure involving use of a protein-free filtrate with additional cleanup of the sample with Lloyd's reagent. None of the 21 endogenous and exogenous substances that we screened interfered. The overall CV at 138 mumol of creatinine per liter is 1.35% and at 539 mumol/L is 0.72%.