Mechanism of automated alkaline methods for the determination of hemoglobin in whole blood based on the micellization of ligated heme in the presence and absence of cyanide

• Published in: Analytica chimica acta 1992-06, Vol.262 (1), p.67-77
• Main Authors: Malin, Michael J., Fan, Sophie S., Benezra, Jeffrey
• Format: Article
• Language: English
• Subjects: Analysis of complex biological substances; Analytical, structural and metabolic biochemistry; Automated alkaline methods; Biological and medical sciences; Blood; Blood and biological fluids; Cyanide; Fundamental and applied biological sciences. Psychology; Haemoglobin; Micelles
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/0003-2670(92)80009-V

Conventional (cyanide-based) and cyanide-free methods for the determination of hemoglobin (Hb) in whole blood have been developed for the Miles H * 1 TM hematology instrument. Concerns with hazards associated with manufacture, transportation and disposal of cyanide-based solutions favor cyanide-free reagents. The cyanide-based method reaches completion in 3 s. The reaction mechanism of whole blood Hb or hemin with a reagent consisting of 20 mM KCN, 20 g l −1 of N,N-dimethylaurylamine N-oxide (LO), in 50 mM Na borate at pH 11.3 was investigated. The red-brown reaction product is micellized dicyanoiron(III)porphyrin based on optical spectra. Deletion of cyanide from this reagent yields a green product, micellized monoaquomonohydroxyiron(III)porphyrin. Proton magnetic resonance line broadening of LO by heme or Hb is consistent with the presence of the heme product distributed within the interior of the micelle. A scheme is presented which shows relationships between alkaline cyanide-based and cyanide-free reagents for the determination of Hb in whole blood.