Hydrogen peroxide

About: Hydrogen peroxide is a research topic. Over the lifetime, 42583 publications have been published within this topic receiving 1043732 citations. The topic is also known as: H2O2 & dioxidane.

Inhibition of erythrocyte pseudoperoxidase activity by treatment with hydrogen peroxide following methanol

Abstract: 10. Ryrfeldt A, Ramsay CH: Whole-body autoradiographic studies on the distribution of trahydrocannabinol (THC) in mice after intravenous administration. Acta Pharm Suec 8:671, 1971 11. Sprague RA, Rosenkrantz H, Thompson GR, Braude MC: Monkey brain and lung respiration after chronic I.V. treatment with 9-tetrahydrocannabinob. Fed Proc 31:909, 1972 12. Thompson GR, Rosenkrantz H, Braude MC: Neurotoxicity of cannabinoids in chronicallytreated rats and monkeys. Pharmacologist 13: 296, 1971

Efficient visible-light-driven selective oxygen reduction to hydrogen peroxide by oxygen-enriched graphitic carbon nitride polymers

Abstract: H2O2 is a green, environmentally friendly potential energy source. The photocatalytic reduction of molecular oxygen to synthesise H2O2 is an eco-friendly strategy compared with the anthraquinone method and H2/O2 direct synthesis. We proposed oxygen-enriched carbon nitride polymer (OCN) models, which were proven to more easily produce 1,4-endoperoxide species and have a high selectivity for molecular oxygen reduction to H2O2, rather than superoxide radicals, through theoretical calculations and experiments. The apparent quantum yield for H2O2 production by OCNs reached 10.2% at 420 nm under an O2 atmosphere, which was 3.5 times higher than that of g-C3N4 and the activity did not decay over 20 h. OCN has a better oxygen reducibility and electron–hole separation efficiency than g-C3N4 and is more prone to 2-electron reduction in the ORR. This work promotes understanding of the mechanism of photocatalytic oxygen reduction and provides a new idea for the design and synthesis of new materials for the preparation of H2O2.

Reduction and inactivation of superoxide dismutase by hydrogen peroxide

Abstract: Reactions of H2O2 with superoxide dismutase were studied by e.p.r. (electron paramagnetic resonance) spectroscopy and other methods. In agreement with earlier work, the Cu2+ of the enzyme is reduced by H2O2, although the reaction does not go to completion and its kinetics are not simple. With dilute enzyme the time for half-reduction with 9mm-H2O2 is about 150ms. It is suggested that the reaction is a one-electron reduction, involving liberation of O2−. On somewhat more prolonged exposure to H2O2, the enzyme is inactivated. For enzyme in dilute solution and over a limited range of H2O2 concentrations, inactivation is first-order with respect to enzyme and reagent, with k=3.1m−1·s−1 at 20–25°C. Inactivation is accompanied by marked changes in the e.p.r. and visible spectra and appears to be associated with destruction of one histidine residue per subunit. It is suggested that this histidine is close to the metal in the native enzyme and essential for its enzymic activity.

Oxo[5, 10, 15, 20-tetra(4-pyridyl)porphyrinato]titanium(IV): an ultra-high sensitivity spectrophotometric reagent for hydrogen peroxide

Abstract: The water-soluble titanium(IV)–porphyrin complex, oxo[5, 10, 15, 20-tetra(4-pyridyl)porphyrinato]titanium(IV)[TiO(tpyH4)4+], was found to enhance the spectrophotometric determination of trace amounts of hydrogen peroxide. A 0.05 mol dm–3 hydrochloric acid solution containing TiO(tpypH4)4+ was used (the Ti—TPyP reagent), the absorbance of which decreased at 432 nm as hydrogen peroxide was added. This was due to the consumption of the TiO(tpypH4)4+ complex following the formation of peroxo[5, 10, 15, 20-tetra(4-pyridyl)porphyrinato]titanium(IV). The decrease in absorbance at 432 nm (ΔA432) was proportional to the concentration of hydrogen peroxide, from 1.0 × 10–8 to 2.8 × 10–6 mol dm–3, in the sample solution (25 pmol–7.0 nmol per assay). The reaction was accelerated by hydrogen ions; the presence of 1.6 mol dm–3 perchloric acid was found to promote complexation to the greatest extent. A ΔA432 of 1.9 × 105 was found for 1 mol dm–3 hydrogen peroxide. A measurement precision of 1.2% for 1.0 × 10–6 mol dm–3 hydrogen peroxide (n= 8) was obtained. The reagent can be used for the determination of hydrogen peroxide in water samples such as tap water and rainwater over the range from 1.05 × 10–7 to 3.34 × 10–5 mol dm–3.