Evaluation of an automated coulometric back-titration analysis of bicarbonate

The bicarbonate module of the Stat/Ion was assessed in a clinical laboratory setting. Within run precision was evaluated by doing replicate analyses of patients' sera. Day-to-day precision was studied by making daily replicate analyses of buffered serum controls. The values for bicarbonate on the Stat/Ion were compared to Skeggs' method for determining carbon dioxide content on the AutoAnalyzer I. It was also compared to the value calculated from the pH and carbon dioxide pressure values obtained on the IL313-03 Blood pH/Gas system. Bilirubin interference was studied.