Abstract
A kinetic flow-injection (FI) method is described for the determination of hydrogen peroxide. This method is based on an iron(III)-catalyzed oxidative coupling of 4-aminoantipyrine with N,N-dimethylaniline by hydrogen peroxide. By measuring the change in the absorbance of the dye formed at 560 nm, 1 × 10-6 - 6 × 10-4 M hydrogen peroxide could be determined with a sampling rate of 15 h-1. The relative standard deviation (n = 30) was 0.8% for 5 × 10-5 M hydrogen peroxide. There was little interference of the co-existing ions and compounds. After introducing some immobilized enzyme reactors to the FI system, the proposed method allowed the determination of glucose and uric acid ranging from 1 × 10-6 to 6 × 10-4 M with relative standard deviations of below 2%. The applicability of the method was demonstrated by determining these substances in serum samples.
