Hydrogen peroxide, addition

H2O2 or urea hydrogen peroxide addition compound... 

Twenty-two grams (0.45 mole) of 70% hydrogen peroxide (Note 1) is added dropwise with efficient agitation to a slurry or partial solution of 36.6 g. (0.30 mole) of benzoic acid (Note 2) in 86.5 g. (0.90 mole) of methanesulfonic acid (Note 3) in a 500-ml. tail-form beaker. The reaction temperature is maintained at 25-30° by means of an ice-water bath. The reaction is exothermic during the hydrogen peroxide addition, which requires approximately 30 minutes. During this period the benzoic acid completely dissolves. 

Paixao and coworkers described a voltammetric electronic tongue able to distinguish milk treated by means of different pasteurization processes. Furthermore, the method proved to be useful for the detection of hydrogen peroxide additions to milk. Such a fraudulent practice was discovered in 2007 in Brazil. The practice was aimed at reducing the bacterial growth in milk, thus lessening the degradation processes. But, it is... 

Hydrogen Peroxide (Additional Information on German Manufacture and Uses During WWII). 

Urea hydrogen peroxide addition compound (UHP) (12.2 mg, 0.13 mmol)... 

In the following first example the liquid ozone concentration and the OH-radical concentration are calculated with semi-empirical formula from the mass balance for ozone (Laplanche et al., 1993). For ozonation in a bubble column, with or without hydrogen peroxide addition, they developed a computer program to predict the removal of micropollutants. The main influencing parameters, i. e. pH, TOC, U V absorbance at 254 nm (SAC254), inorganic carbon, alkalinity and concentration of the micropollutant M are taken into consideration. 

The exocyclic double bond of the enamide 97 was reacted with diborane, followed by alkaline hydrogen peroxide addition, affording the trans-alcohol 98 <1996J(P1)545>. 

Beschkov, V., Bardarska, G., Gulyas, H., and Sekoulov, I., Degradation of triethylene glycol dimethyl ether by ozonation with UV irradiation or hydrogen peroxide addition, Water Sci. Technol., 36, 131-138, 1997. 

Permanent hair colors can be achieved with tint shampoos. The shampoo base is adjusted to an alkaline pH and contains oxidation dye intermediates. Before application, it is mixed with hydrogen peroxide or a hydrogen peroxide addition compound. In comparison with oxidation hair dyes, tint shampoos employ lower concentrations of base and oxidant. This suppresses the simultaneous bleaching process that occurs during dyeing (see Section 5.4.2). As a result, damage to the keratin in hair is diminished, but the uniform coloring action is lost. 

Figure 5.26 Speeding up the oxidation of 2-methylnaphthalene (2MN) in a microreactor by virtue of faster hydrogen peroxide addition and higher temperatures (by courtesy of Wiley-VCH Verlag GmbH) [57],...

For hydrogen peroxide addition products, some deflagration was observed in the case of sodium carbonate-hydrogen peroxide addition products, but all others show either no ignition or little increase in pressure after ignition. 

Potassium nitrate and sodium carbonate-hydrogen peroxide addition products are selected as typical oxidizers, and various flammable materials in combination with the oxidizers selected were tested for deflagration rate. The results in comparison with the oxidizers are shown in Table 3.26. Effects of the flammables on the deflagration for selected oxidizers are evaluated as follows ... 

Chrom Q (60-80 mesh), 170°C, 50 mL of nitrogen per min. The retention times for the perhydrophenaienol and dioxaborole are 6.4 and 15.2 min, respectively. For TLC analyses, Analtech silica gel plates bearing the material were eluted by 1 2 methylene chloride-petroleum ether, and visualized with phosphomolybdic acid perhydrophenaienol, Rf 0.4 dioxaborole, Rf 0.9. The checkers found that the reaction was essentially complete after addition of the hydrogen peroxide. Additional heating did not lower the yield of product. 

It will often be necessary to avoid sulfone formation, and this can be achieved by carrying out the reaction below 50 °C, and using only stoichiometric amounts of hydrogen peroxide.373 For example, 1,4-dithiane can be selectively converted to the mono- and bis-sulfoxide by proper control over the hydrogen peroxide addition rate.374 Azeotropic removal of water by the addition of suitable solvents can also increase selectivity.375 However, if sulfones are required, then elevated temperatures should be used.376... 

Chloromercurithiophene or mercury 2 2 -dithienyl is treated with arsenious chloride and the product warmed on the water-bath. The filtrate from this mixture is treated with aqueous sodium hydroxide, then with hydrogen peroxide. Addition of barium chloride then helps to remove any inorganic arsenic which has not crystallised out as sodium arsenate. The whole is filtered, the filtrate freed from barium and sulphuric acid and evaporated down after the addition of concentrated hydrochloric acid. The residue is dissolved in alcohol, boiled with charcoal, and treated with sodium hydroxide. The sodium salt of the arsinic acid crystallises out in transparent, colourless, non-deliquescent, rhombic plates, which are very soluble in water. The free acid forms tufts of needles, M.pt. 185 5° C., fairly soluble in water or alcohol. At 106° to 108° C. it is converted into the corresponding anhydride. Sulphurous acid in the presence of a trace of hydriodic acid reduces it to thienyl-2-arsenoxide, whilst with sodium hydrosulphite it yields 2 2 -arsenothiophe-ne,... 

In this case, the liver might contain a different chemical that acts like manganese dioxide when added to hydrogen peroxide. Additional experiments would reveal that the liver does in fact contain such a chemical. Experimental results can also lead to more experiments. Perhaps the chemical that acts like manganese dioxide can be found in other parts of the body. 

Figure 32 shows the amperometric response of the biosensor in the presence of different hydrogen peroxide concentration. As shown a well defined response was observed after hydrogen peroxide addition. The values of KM, 0.96 mM for hemoglobin and 1.37 mM for catalase indicates the immobilized biomolecules into nickel oxide nanoparticles retained their native activity. 

Nitric Acid Concentration. The nitric acid concentration has a major effect on the relative filtration time. This is indicated by the generally steep slopes of the plots in Figures 1, 2, and 3. Irrespective of the other variables, the relative filtration time decreases as the nitric acid concentration increases. The interaction between the nitric acid concentration and the hydrogen peroxide addition rate is notable (Figure 2). 

At low acid concentrations, there is a considerable difference in filtration times between the three levels of the hydrogen peroxide addition rate. But as the acid concentration increases, this difference decreases dramatically. 

Hydrogen Peroxide Addition Rate. Although the effect is small, the slower the rate of hydrogen peroxide addition, the higher the concentration of plutonium in the filtrate (Figure 11). 

The identification of those variables that have a major effect on plutonium peroxide precipitation was done in two ways. The first way used t-test values associated with each variable. The comparative magnitude of these values indicates the relative importance of the variable. The second way involved a subjective evaluation of the relative importance of each of the variables based on a visual comparison of the graphs constructed from the experimental data (Figures 1 through 12 plus a couple of dozen other comparable graphs that could not be included in this paper because of space limitations). The results of the subjective evaluation indicate that only the nitric acid concentration and the rate of hydrogen peroxide addition have a major effect on the relative filtration time. The other four variables influence the... 

The larger the value associated with a variable, the more significant is the effect of that variable. On this basis, the variables that are most important to the relative filtration time are the nitric acid concentration and the rate of hydrogen peroxide addition. The variables most important to the plutonium concentration in the filtrate are the nitric acid, hydrogen peroxide and impurity concentrations. Thus, the t-test data is in general agreement with the subjective evaluation. 

The variable that is most important to the relative filtration time is the nitric acid concentration. This is followed by the rate of hydrogen peroxide addition. The remaining four variables are of less importance, and, in fact, are not statistically significant. The critical t value for significance at the 35% confidence level is 2.013 and these four variables have t values lower than this. 

As shown in Fig.l, either TMPyP or TSPP showed almost no emission when they are used alone whereas the emission from the one-to-one mixture of those solutions was quite strong. The time profiles of the emission were quite similar to those obtained with pure hydrogen peroxide. Addition of catalase suppressed the emission completely. Those observations assured us that the chemiluminescence is solely due to the hydrogen peroxide produced by the light irradiation. 

Experiments tvith slow continuous hydrogen peroxide addition were also performed. After dissolving the substrate the hydrogen peroxide was added at a rate of 1.2 ml/h. The spectrum of products was not different from that obtained upon addition of the oxidant in one portion. Hence, the oxidation of 1-0-methyl glucuronic acid is also catalysed by homogeneous titanium hydroperoxide. 

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