Spectrophotometric determination of hydrogen peroxide, glucose, uric acid, and cholesterol using peroxidase-like activity of an Fe(III) complex of thiacalix[4]arenetetrasulfonate attached to an anion-exchanger.

An iron(III) complex of thiacalix[4]arenetetrasulfonate attached to an anion-exchanger (Fe(3+)-TCASA-500) showed high peroxidase-like catalytic activity at pH 5 - 8 for the formation of quinoid dye, following the color reaction between 3-methyl-2-benzothiazolinone hydrazone (MBTH) and N-ethyl-N-(3-sulfopropyl)aniline (ALPS) in the presence of H2O2. This catalytic activity of Fe(3+)-TCASA-500 for the MBTH-ALPS system was applied for the spectrophotometric determination of H2O2, glucose, uric acid, and cholesterol. The calibration curves were linear in the concentration range from 1.0 to 15 μg of H2O2 in a 1.0-mL sample solution, and from 5.0 to 60 μg of glucose, 2.0 to 30 μg of uric acid, and 11.6 to 116 μg of cholesterol in a 0.5-mL sample solution. The apparent molar absorptivity of H2O2 was determined as 2.31 × 10(4) L mol(-1) cm(-1), which was about 70% of that by peroxidase under the same conditions. The determination method using Fe(3+)-TCASA-500 was applied for the determination of glucose and uric acid in both control sera I and II.