1977 年 97 巻 1 号 p. 41-45
The formation of mixed ligand complexes in Ti(IV)-Xylenol Orange(XO)-H2O2, Ti-(IV)-Chromazurol S(CAS)-H2O2, Ti(IV)-ethylenediaminetetraacetic acid (EDTA)-H2O2, and Co(II)-EDTA-H2O2 systems was studied by spectrophotometry. In Ti(IV)-XO-H2O2 system, the constant absorbance (λmax 562 nm) was obtained under the condition of [XO]/[Ti(IV)]≥1 in the pH 2-4 region. When [CAS]/[Ti(IV)] ratios were within 3-6, Ti(IV)-CAS-H2O2 system gaved distinct maximum at 557 nm in the pH range of 4.5-5.2. The absorption spectra of Ti(IV)-EDTA-H2O2 (pH 1-8) and Co(II)-EDTA-H2O2 (containing≥0.01N NaOH) systems exhibited maxima at 365 and 580 nm, respectively. In all cases, the absorbance at λmax was stable and proportional to the concentration of H2O2. The conditions for the colorimetric determination of H2O2 using M-Y reagents (M=meta1 ion, Y=chelating agent) were examined in detail. The reagents were found to be applicable to the determination of H2O2 in the following concentration ranges : Ti(IV)-XO reagent, 3×10-6 to 1×10-4M H2O2; Ti(IV)-CAS reagent, 2×10-6 to 5×10-5M H2O2; Ti(IV)-EDTA reagent, 1×10-5 to 2×10-3M H2O2 and Co(II)-EDTA reagent, 5×10-4 to 1×10-2M H2O2. Ti(IV)-XO and Ti(IV)-CAS reagents may be significant for the determination of traces of H2O2. Co(II)-EDTA reagent may be useful for the detection of H2O2, because of the intense violet coloration by the formation of Co(II)-EDTA-H2O2 complex.