Oxidation by persulfate

The treatment of polonium(lV) with nitric acid/potassium permanganate under reflux yields a sludge of manganese dioxide which contains all the polonium originally present the valency state is uncertain. Polonium (IV) in weighable amounts is not oxidized by persulfate, ceric salts or chlorine in alkaline solution (12), although trace scale work indicates that both ceric salts and dichromate do oxidize polonium to polonium(VI) (94). 

Another example is represented by the oxidative decarboxylation of oc-ketoacids in the presence of the S2082 /Ag+ redox system, which leads to the formation of acyl radicals by means of the intermediate Ag2+ (Equations 14.5 and 14.6) [10]. In this case, the re-aromatization of the ring can occur according to two parallel paths oxidation by persulfate (Scheme 14.1a) and by Ag(II) (Scheme 14.1b). Thus, this system needs more than the stoichiometric quantity of persulfate, as it both reacts... 

The yield of organic pollutant oxidation by persulfate y is defined as the ratio of stoichiometric persulfate variation for the oxidation of organic pollutant A Cs, with respect to the persulfate that is effectively consumed AC ... 

In accordance with the suggested interpretations (5) of the effects of silver ions on the kinetics of oxidation by persulfate ions, the oxidation of Am (III) occurs according to equations (3) and (4). 

A significant recent development has been the synthesis of PAn s in which chiral substituents have been covalently attached to the aniline rings. Chiral ethers were bound to the aniline monomer before its chemical oxidation by persulfate,139 producing chiral PAn s possessing strong optical activity as evidenced by their CD spectra. Previous routes to chiral PAn s had employed chiral dopant anions to induce chirality into PAn chains. 

The basis for such catalysis (e.g., silver ion-catalyzed oxidations by persulfate) is that electron transfer from the reductant to the catalyst, followed by electron transfer from the catalyst to the oxidant, is faster than direct electron transfer from the reductant to the oxidant. A necessary, but insufficient, requirement for such catalysis is the accessibility of two oxidation states of the catalyst, neither of which must be too stable with respect to the other. For reasons that are still not well understood (despite the progress in the understanding of the mechanisms and reactivity patterns of electron transfer reactions), copper and silver salts are especially effective in this type of catalysis. 

The photooxidation technique produced values of the same order as those produced by persulfate oxidation. There is no reason to expect that the two methods should be equally effective for all compounds to be found in seawater it is surprising that so httle comparative work has been done on these methods. 1 suspect the reasons for this are first, that both methods are effective oxidants for almost all of the pure compounds so far tested, and second, that few laboratories care to tool up for both of these methods. There are a fair number of intercomparisons between persulfate oxidation and high temperature catalytic oxidation, as a result of the controversy noted earher, but very few direct comparisons of UV and persulfate in one case [74], seawater samples run in parallel by both methods gave results some 15% lower by persulfate oxidation. While this might lead us to believe that UV oxidation decomposed some compounds not oxidized by persulfate, the possibility exists that the difference is due primarily to reactions between the sulfate radical and the chloride ion [75, 76], resulting in a lower efficiency of oxidation. The close correspondence between persulfate and UV oxidation and HTCO measurements on freshwater samples [77-79] reinforces this interpretation. 

Microetch In acidic environments, copper is oxidized by persulfate (SiOs ), peroxide (H2O2), or proprietary monopersulfate acid mixes. Sulfuric acid is common to all types of microetch. 1-2 /tm of Cu is oxidized to Cu and dissolved. 1... 

Manganese salts are oxidized by persulfate in the presence of silver ions to permanganate, whose violet color may prevent the discernment of the occurrence of the chromate-diphenylcarbazide reaction. However, sodium azide may be added it completely reduces permanganates, but affects chromates only slightly (see page 192). 

Oxidation. Nitroparaffins are resistant to oxidation. At ordinary temperatures, they are attacked only very slowly by strong oxidi2ing agents such as potassium permanganate, manganese dioxide, or lead peroxide. Nitronate salts, however, are oxidi2ed more easily. The salt of 2-nitropropane is converted to 2,3-dimethyl-2,3-dinitrobutane [3964-18-9], acetone, and nitrite ion by persulfates or electrolytic oxidation. With potassium permanganate, only acetone is recovered. 

AHyl alcohol can be easily oxidized to yield acrolein [107-02-8] and acryhc acid [79-10-7]. In an aqueous potassium hydroxide solution of RuQ., aHyl alcohol is oxidized by a persulfate such as K2S20g at room temperature, yielding acryhc acid in 45% yield (29). There are also examples of gas-phase oxidation reactions of ahyl alcohol, such as that with Pd—Cu or Pd—Ag as the catalyst at 150—200°C, in which ahyl alcohol is converted by 80% and acrolein and acryhc acid are selectively produced in 83% yield (30). 

Silver(II) Oxide. Silver(II) oxide [1301 -96-8, 35366-11-1], AgO, is prepared by persulfate oxidation of Ag20 in basic medium at 90°C or by the... 

Oxidation. Citric acid is easily oxidized by a variety of oxidizing agents such as peroxides, hypochlorite, persulfate, permanganate, periodate, hypobromite, chromate, manganese dioxide, and nitric acid. The products of oxidation are usually acetonedicarboxyhc acid (5), oxaUc acid (6), carbon dioxide, and water, depending on the conditions used (5). 

The total cerium content in the single crystal samples on the basis of rare-earth elements is determined by photometry after Ce(III) oxidation by ammonium persulfate. The Ce(III) content is calculated from the difference. Comparison of the determination results of the total cerium content obtained by photometric and atomic emission methods for Li GdlBO ljiCe demonstrated the elaborated procedure precision and systematic error absence. 

Oxidation of monophenols to polyphenols or oxidation of aromatic methyl groups by persulfates (Caro s acxJ)... 

Although these compds are readily formed, they are also readily decompd, eg by the addition of a solvent that dissolves one of the two constituents. The nature of these non-covalent compds is discussed by Urbanski (Ref 35) Picric Acid is not resistant to strong oxidizing agents. It is oxidized by boiling nitric acid to yield oxalic add. Boiling with ammonium persulfate results in a complete oxidation, according to the equation ... 

We can study the dependence of the rate on the concentration of one substance by using one experiment even when two or more substances are involved. To see how this is done, consider the rate law for the overall second-order oxidation of iodide ions by persulfate ions ... 

Williams [176] has studied the rate of oxidation of C-labelled glucose in seawater by persulfate. After the oxidation, carbon dioxide was blown off and residual activity was measured. For glucose concentrations of 2000, 200, and 20 xg/l, residual radioactivities (as percentage of total original radioactivity) were 0.04, 0.05, and 0.025, respectively, showing that biochemical compounds are extensively oxidised by persulfate. With the exception of change of temperature, modifications of conditions had little or no effect. Oxidation for 2.5 h at 100 °C was the most efficient. 

An example of an automated colorimetric method, oxidation by ultraviolet irradiation for the determination of dissolved organic carbon in the presence of potassium persulfate [ 87], is that of Schreurs [86 ]. The method uses a Technicon analyser to measure dissolved organic carbon, is fast and precise, and may be used to measure dissolved organic carbon in both seawater and fresh water over the range 0.1 -10 mg C per litre. 

Oh S-Y, Kim H-W, Park J-M, Park H-S, Yoon C (2009) Oxidation of polyvinyl alcohol by persulfate activated with heat, Fe2-t, and zero-valent iron. J Hazard Mater 168 346-351... 

Oxidation of aminopyridines with Caro s acid gives nitropyridines the use of peroxy-trifluoroacetic acid leads to nitropyridine JV-oxides (60JOC1716). Oxidation with alkaline hypochlorite converts aminopyridines into symmetrical azopyridines, and azoxypyridines are formed by oxidation with persulfate (59YZ549). 

The 2 -isomer is best formed by persulfate oxidation of 2-amino anthraquinone [Kirk Othmer 7 (1947), 9551... 

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