Hydrogen peroxide sources

Hydrogen peroxide system including a hydrogen peroxide source, storage, metering, and injection pump. 

Some efforts were made in order to obtain good enantioselectivities in the epoxidation of simple olefins using methyltrioxorhenium (MTO), urea hydrogen peroxide (UHP) and six different chiral non racemic 2-substituted pyridine ligands, some of which are novel UHP was chosen as the hydrogen peroxide source in order to avoid unfavourable competition from water for vacant sites on the metal. However, poor enantioselectivity was reached (3-12% ee). 

Another anhydrous hydrogen peroxide source which has found use as an oxidation reagent is bis(trimethylsilyl) peroxide, 3., which can be prepared... 

Barium peroxide hydrogen peroxide source Urea peroxide hydrogen source... 

CiP was also used in the synthesis of heteroaryl methyl sulfoxides combined with glucose oxidase as a hydrogen peroxide source, as shown in Scheme 6.1 [21]. Optically active heteroaryl alkyl sulfoxides are interesting compounds in organic chemistry, as they present a chelating center that can be used in asymmetric s mthe-sis. Moderate to good results were achieved depending on the substrate structure. The best results were obtained for the oxidation of sulfides with electron-rich heterocycles. 

The peroxyoxalate chemiluminescence is used here, too warning capsules against infiltrating troops were developed containing an active oxalate, a fluorescer, and - as a hydrogen peroxide source, producing H2O2 on contact with air - an anthrahydroquinone derivative (258). 

This enzyme Is widely distributed, more particularly in plants. Three important sources of the enzyme are horse-radish, turnips and milk. Peroxidase is capable of activating both hydrogen peroxide and a suitable substrate so that the latter is oxidised, although hydrogen peroxide alone may be incapable of affecting this change. It sometimes happens that hydrogen pcr-... 

The method is basically an application of the Wacker oxidation except that the catalyst used is palladium acetate ( Pd(AcO)2 or Pd(02CCH3)2). the solvent is acetic acid or tert-butyl alcohol and the oxygen source is the previously suggested hydrogen peroxide (H202)[17]. 

Comparison to the Raschig Process. The economics of this peroxide process in comparison to the Raschig or hypochlorite—ketazine processes depend on the relative costs of chlorine, caustic, and hydrogen peroxide. An inexpensive source of peroxide would make this process attractive. Its energy consumption could be somewhat less, because the ketazine in the peroxide process is recovered by decantation rather than by distillation as in the hypcochlorite process. A big advantage of the peroxide process is the elimination of sodium chloride as a by-product this is important where salt discharge is an environmental concern. In addition to Elf Atochem, Mitsubishi Gas (Japan) uses a peroxide process. 

Obsolete uses of urea peroxohydrate, as a convenient source of aqueous hydrogen peroxide, include the chemical deburring of metals, as a topical disinfectant and mouth wash, and as a hairdresser s bleach. In the 1990s the compound has been studied as a laboratory oxidant in organic chemistry (99,100). It effects epoxidation, the Baeyer-Villiger reaction, oxidation of aromatic amines to nitro compounds, and the conversion of sodium and nitrogen compounds to S—O and N—O compounds. 

S. G. Huling and co-workers. Enhanced Bioremediation Utilic ng Hydrogen Peroxide as a Supplemental Source of Ouygen A Eaboratoy and Field Study,... 

R can be a variety of stmctures. Z is a leaving group and typically the conjugate base of a weak acid whose piC can range from 5 to 20 (86). The hydrogen peroxide is typically incorporated into the bath by a dding a soHd source of peroxide such as sodium percarbonate or the mono- or tetrahydrate of sodium perborate (86). 

Hair. Hydrogen peroxide is the most satisfactory bleaching agent for human hair. Solutions containing 3—4% hydrogen peroxide, available from dmg stores and supermarkets, are commonly used. In beauty shops, more rapid bleaching is desired and a 5—6% solution is used. Ammonium hydroxide is usually the source of aLkaliuity in both systems (see Cosmetics Hair preparations). 

Industry sources indicate worldwide production of hydrogen peroxide and sodium perborate mono- and tetrahydrate, which are used almost exclusively for bleach appHcations, is 1.1 x 10 t per year and 6.4 x 10 t per year, respectively, in 1990. 

Sulfur Dioxide EPA Method 6 is the reference method for determining emissions of sulfur dioxide (SO9) from stationary sources. As the gas goes through the sampling apparatus (see Fig. 25-33), the sulfuric acid mist and sulfur trioxide are removed, the SO9 is removed by a chemical reaction with a hydrogen peroxide solution, and, finally, the sample gas volume is measured. Upon completion of the rim, the sulfuric acid mist and sulfur trioxide are discarded, and the collected material containing the SO9 is recovered for analysis at the laboratory. The concentration of SO9 in the sample is determined by a titration method. 

Wet Oxidation (WO) The oxidation of oxidizable substances in water using the oxygen in air, pure or enriched oxygen, hydrogen peroxide, nitric acid or some other oxidizing agent as the source of the oxidant. The oxidation process is conducted at subcritical temperatures (<374°C). 

One of the important consequences of neuronal stimulation is increased neuronal aerobic metabolism which produces reactive oxygen species (ROS). ROS can oxidize several biomoiecules (carbohydrates, DNA, lipids, and proteins). Thus, even oxygen, which is essential for aerobic life, may be potentially toxic to cells. Addition of one electron to molecular oxygen (O,) generates a free radical [O2)) the superoxide anion. This is converted through activation of an enzyme, superoxide dismurase, to hydrogen peroxide (H-iO,), which is, in turn, the source of the hydroxyl radical (OH). Usually catalase... 

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