Determination of Carboxyhemoglobin in Heated Blood—Sources of Error and Utility of Derivative Spectrophotometry

Abstract
The cause for discrepancies in results from different methods of the carboxyhemoglobin (HbCO) analysis on the blood from bodies of burn victims was investigated. Blood samples with 0, 50, and 100% carbon monoxide (CO) saturation were heated at various temperatures for some time and then analyzed. Carboxyhemoglobin content was determined by the fourth-derivative spectrophotometric method and compared with results from the usual two-wavelength method. For total hemoglobin measurement, the fourth-derivative technique and cyanmethemoglobin method were used. Turbidity in blood samples, which occurred when samples were heated above 50°C, affected the analysis. At about 70°C, coagulation and hemoglobin degeneration occurred accelerating the errors of determined values. The fourth-derivative technique, however, proved to be independent of the turbidity and would be useful for the analysis on the blood without hemoglobin degeneration.