Catalytic Spectrophotometric Determination of Hemoglobin

Based on its peroxidase property,a new method of catalytic spectrophotometric determination of hemoglobin (Hb) was proposed.In an ammoniacal buffer medium of pH 9.5,oxidation of acid chrome blue K (ACBK) by hydrogen peroxide was catalyzed by hemoglobin,leading to acceleration of color-fading of the reaction system.Under the optimized reaction condition,the magnitude of decrease in absorbance (ΔA) due to catalytic effect was found to keep a linear relationship with the concentration of Hb in the range of 7.0×10-10-9.0×10-8mol·L-1,with its detection limit (3Sb/k) of 1.7×10-11mol·L-1,and apparent molar absorptivity of 3.9×108L·mol-1·cm-1.In application of the proposed method to the determination of Hb in urine,values of RSD′s (n=5) obtained were in the range of 1.9%-4.2%,and values of recovery were in the range of 96.0%-102.0%.A brief discussion on the mechanism of the enzyme catalysis was also given.