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.

Ligand-enhanced reactive oxidant generation by nanoparticulate zero-valent iron and oxygen.

Abstract: The reaction of zero-valent iron or ferrous iron with oxygen produces reactive oxidants capable of oxidizing organic compounds. However, the oxidant yield in the absence of ligands is too low for practical applications. The addition of oxalate, nitrilotriacetic acid (NTA), or ethylenediaminetetraacetic acid (EDTA) to oxygen-containing solutions of nanoparticulate zero-valent iron (nZVI) significantly increases oxidant yield, with yields approaching their theoretical maxima near neutral pH. These ligands improve oxidant production by limiting iron precipitation and by accelerating the rates of key reactions, including ferrous iron oxidation by oxygen and hydrogen peroxide. Product yields indicate that the oxic nZVI system produces hydroxyl radical (OH·) over the entire pH range in the presence of oxalate and NTA. In the presence of EDTA, probe compound oxidation is attributed to OH· under acidic conditions and a mixture of OH· and ferryl ion (Fe[IV]) at circumneutral pH.

Chemical treatment of pesticide wastes. Evaluation of Fe(III) chelates for catalytic hydrogen peroxide oxidation of 2,4-D at circumneutral pH

Abstract: A number of structurally diverse organic and inorganic polydentate chelators were tested for their ability to solubilize Fe(III) at pH 6 and catalyze the oxidation of 0.1 mM (22 ppm) 2,4-dichlorophenoxyacetic acid (2,4-D) by 10 mM (340 ppm) hydrogen peroxide in aerated aqueous solution. Of 50 compounds tested, 20 organic compounds gave soluble complexes capable of oxidizing 2,4-D in periods ranging from minutes to less than 5 h. The reaction rate was proportional to the concentration of H 2 O 2 and inversely proportional to the concentration of chelator (...)

Mechanisms of cerebral vasodilation by superoxide, hydrogen peroxide, and peroxynitrite.

Abstract: We investigated the role of potassium channels in the vasodilator action of hydrogen peroxide, peroxynitrite, and superoxide on cerebral arterioles. We studied the effect of topical application of these agents in anesthetized cats equipped with cranial windows. Hydrogen peroxide and peroxynitrite induced dose-dependent dilation that was inhibited by glyburide, an inhibitor of ATP-sensitive potassium channels. Superoxide, generated by xanthine oxidase acting on xanthine in the presence of catalase, also induced dose-dependent dilation of cerebral arterioles that was unaffected by glyburide but inhibited completely by tetraethylammonium chloride, an inhibitor of calcium-activated potassium channels. The vasodilations from hydrogen peroxide, peroxynitrite, or superoxide were unaffected by inhibition of soluble guanylate cyclase with LY-83583. The findings provide pharmacological evidence that hydrogen peroxide and peroxynitrite reversibly dilate cerebral arterioles by activating ATP-sensitive potassium channels, probably through an oxidant mechanism, whereas superoxide dilates cerebral arterioles by opening calcium-activated potassium channels. Activation of soluble guanylate cyclase is not a mediator of the vasodilator action of these agents in cerebral arterioles.