Investigation of cyanocobalamin interferences to an electrochemical based hemoglobin test system

The structure of vitamin B-12 with a cobalt ion in the center is similar to the structure of heme with an iron center in the hemoglobin. The suspicion that the presence of vitamin B-12 in venous blood samples caused interference in readings of hemoglobin levels when using the BeneCheck hemoglobin test system, an electrochemical based strip and meter, was investigated in this study. Venous blood samples with 5 mg/dL of vitamin B-12 induced a positive error of 13% in the hemoglobin measurement, while 10 mg/dL of vitamin B-12 caused a positive error of 30% in the hemoglobin measurement. However, 1 mg/dL of vitamin B-12, a concentration much higher than that of venous blood concentrations in patients under B-12 treatment, did not cause an error in the hemoglobin measurement. These results suggest that the BeneCheck hemoglobin test system is suitable for clinical application for patients under B-12 treatment because the dosage is below 1 mg/dL.