Chlorpromazine is an excellent chromogen for determining micro-quantities of hemoglobin. The oxidation of chlorpromazine by peroxidase activity of hemoglobin is coupled to a non-enzymatic reaction of second-order. Kinetic analysis of the overall system leads to a discussion about the optimal assay conditions. Spectrophotometric progress curves for the accumulation of the chlorpromazine cation radical during the reaction have been obtained, and further analyzed by non-linear regression. The use of a linear calibration curve of the enzymatic reaction rate against hemoglobin concentration is proposed for its determination. © 1991.
Vázquez, A., Tudela, J., Varón, R., & García-Cánovas, F. (1991). Determination of hemoglobin through its peroxidase activity on chlorpromazine. Journal of Biochemical and Biophysical Methods, 23(1), 45–52. https://doi.org/10.1016/0165-022X(91)90049-3