Titanium(IV)-ポルフィリン錯体を吸光分析試薬とする血清尿酸の定量

抄録

Aqueous solution of oxo [5, 10, 15, 20-tetra (4-pyridyl) porphyrinato] titanium (IV) complex, a Ti-TPyP reagent, was found to be very useful for the spectrophotometric determination of hydrogen peroxide. The reagent (λ_max 432 nm) reacts with hydrogen peroxide to form a monoperoxocomplex, resulting in a significant decrease of the absorbance at 432 nm. The decrease (ΔA) in absorbance was proportional to the concentration of hydrogen peroxide. The Ti-TPyP reagent was successfully applied to the assay of uric acid in the serum, using uricase to produce hydrogen peroxide through enzymatic oxidation. Using only 5 μl serum, a linear relationship was obtained between ΔA and uric acid concentration in the serum ranging from 5×10^-6 to 1×10^-3 M. The apparent molar ΔA of uric acid was 2.2×10⁵ M^-1 cm^-1. The relative standard deviation of repeated runs (n=8) was 2.8% at 3.77×10^-4 M uric acid. The analytical recovery of uric acid (5×10^-4M) added to the serum was 96.8 to 105.0%. No pre-concentration and deproteinization were required to determine uric acid in the serum by the present method because of the high sensitivity and selectivity of the Ti-TPyP reagent for hydrogen peroxide.