Syntheses and Evaluations of Water-Soluble Lophine Derivatives for Highly Sensitive Colorimetric Determination of Hydrogen Peroxide Developed in the Enzymatic Reaction of Biological Substances

Abstract

New hydrogen donors, water soluble lophine derivatives, were synthesized for the determination of hydrogen peroxide developed in the enzymatic reaction of biological substances. These chromogens have high absorptivity ; extinction coefficient is 40 000-50 000 upon oxidation with hydrogen peroxide in the presence of peroxidase. A single work reagent is used for the determination of uric acid in the serum ; the reaction is complete in less than 5 min at 37°C. The blue dye is formed at 640 nm ; a blank sample measurement is not needed. The standard curve for the method is linear for uric acid ranging from 2.5 to 25 mg/dl. Average analytical recovery of uric acid in the human sera exceeded 99% ; within-run and between-run precision studies showed CV's ⪈2.5 and ⪈3.5%, respectively. The method correlated well with the standard uricase-ultraviolet method ; the regression equation is y=0.988x+0.426 (mg/dl) and the correlation coefficient (γ) is 0.977 (n=11).