Carbon monoxide in blood: analytical method and sources of error

Abstract

A method is described for the analysis of small concentrations of carboxyhemoglobin in blood in which the CO is dissociated from the hemoglobin by oxidizing the latter to methemoglobin with ferricyanide and measured as a gas in an infrared analyzer. The method has a sd of ±0.006 ml/100 ml in the range from 0.1 to 1.0 ml/100 ml. Data are presented which indicate that CO can be formed in a blood sample in vitro if the temperature during oxidation with ferricyanide is higher than about 60 C, if the pH of the reacting solution is 10 or higher, and if metallic mercury is not present during the reaction. It was demonstrated that additional CO is not formed during the analysis with the method described and that the method is highly specific for CO. blood carboxyhemoglobin; carbon monoxide; blood gases; carbon monoxide production; hemoglobin oxidation Submitted on July 19, 1963