Analysis for carboxyhemoglobin by gas chromatography and multicomponent spectrophotometry compared

Abstract

Measurements of carboxyhemoglobin (HbCO) by gas chromatography (GC) were compared with those obtained by multicomponent spectrophotometric analyis (MCA). Correlation was good for HbCO ranges (proportion of total hemoglobin) of 1.5 to ≤5% (GC = 0.94 MCA + 0.37%, n = 25, r = 0.98); 5.0 to ≤ 10.0% (GC = 0.89 MCA + 0.63%, n = 19, r = 0.93); >10% (GC = 1.01 MCA - 0.02%, n = 22, r = 0.99); and >0% (GC = 1.01 MCA - 0.10%, n = 95, r = 1.00). The correlation is lower for the clinically normal range of 0 to ≤1.5% (GC = 0.65 MCA + 0.24%, n = 29, r = 0.87). The gas-chromatographic method is linear for HbCO proportions of 30% to as little as 0.15%. Re-analysis of blood samples after two-month storage at 4°C showed that samples remained stable under these conditions.