1993 Volume 42 Issue 6 Pages 363-367
A sensitive flow-injection analysis using the Ti-TPyP reagent was developed for the determination of trace amounts of hydrogen peroxide. The reagent, which is an acid solution containing oxo [5, 10, 15, 20-tetra (4-pyridyl) porphyrinato] titanium (IV) {TiO (tpypH4)4+}, reacts with hydrogen peroxide to form a monoperoxo complex {TiO2(tpypH4)4+}, which exhibits an absorption maximum at 450 nm. A flow-injection manifold comprises two channels system. The molar absorptivity (ε) of the complex was found to be 1.1×105 M-1 cm-1. The absorbance was measured as the peak height in the FIA system. The linear response was obtained over the range of 1×10-81×10-5 M hydrogen peroxide and the detection limit was 5×10-9 M for a 100 μl sample injection. The method was used to analyze 30 samples per hour, the results were accurate with a relative standard deviation of 0.97% for the injection of 1×10-6 M hydrogen peroxide (n=10). The concentration of hydrogen peroxide in rainwater samples collected in Tokyo area (Hachioji) was determined by this method over the range of 7×10-74.3×10-5 M.
