ELIMINATION OF BILIRUBIN INTERFERENCE IN CREATININE ASSAYS BY ROUTINETECHNIQUES - COMPARISONS WITH A HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY METHOD

The aim of this study was to find a method for creatinine analysis una ffected by jaundice by comparing four different methods with high perf ormance liquid chromatography (HPLC) as a reference method. The method s investigated were Kodak DTSC single slide, Boehringer alkaline picra te with and without blank correction and a Boehringer enzymatic method , the last three using the Hitachi 737 analyser. HPLC results were com pared with the results of the methods studied. In addition, graphs plo tting the difference from the HPLC result against the bilirubin concen tration were made; the ideal method would yield a slope and intercept of zero. While all methods showed a positive bias compared with HPLC, the Kodak slide and the Boehringer alkaline picrate with blank correct ion methods eliminated bilirubin interference and we have changed to t he latter method as a consequence of this work.