Nitrite, oxidation

The mechanism of the reaction has not been elucidated. Presumably several reactions occur simultaneously. Thiocyanates react with iron(III) salts with the formation of red-colored complexes. In sulfuric acid medium nitrate or nitrite oxidize diphenylamine to... 

Cytochrome c is a heme containing protein which occurs in muscle at lower concentrations than does myoglobin. It was demonstrated some time ago (18) that oxidized cytochrome c reacts with gaseous nitrite oxide to produce a nltrosyl compound. Recent work (19, 20, 21) has examined the reactions of cytochrome c with nitrite and the contribution of the product formed to cured meat color in considerably more detail. The general conclusion is that even at the pH normally encountered in meat, the reaction can take place in the presence of ascorbic acid but probably does not affect meat color because of the unstable nature of the reaction product and the low concentration. 

Generally, ammonia oxidation is slower than nitrite oxidation and, therefore, no nitrite production is observed. However, when the amount of carbon source available in the effluent is not high enough to complete the denitrification process (low COD/N ratio), the addition of external organic matter is... 

A mixture of the nitrite with sodium thiocyanate explodes on heating [1], Preparation of a molten salt bath from 0.45 kg of potassium thiocyanate (reducant) and 1.35 kg of sodium nitrite (oxidant) led to a violent explosion on melting, which... 

J.M. Zen, A.S. Kumar, and H.W. Chen, Electrochemical behavior of stable cinder/Prussian blue analogue and its mediated nitrite oxidation. Electroanalysis 13, 1171-1178 (2001). 

Describe why nitrites (oxidizing agents) diminish the oxygen-carrying capability of the blood. 

Copper(II) sulfate Cumene hydroperoxide Cyanides Cyclohexanol Cyclohexanone Decaborane-14 Diazomethane 1,1-Dichloroethylene Dimethylformamide Hydroxylamine, magnesium Acids (inorganic or organic) Acids, water or steam, fluorine, magnesium, nitric acid and nitrates, nitrites Oxidants Hydrogen peroxide, nitric acid Dimethyl sulfoxide, ethers, halocarbons Alkali metals, calcium sulfate Air, chlorotrifluoroethylene, ozone, perchloryl fluoride Halocarbons, inorganic and organic nitrates, bromine, chromium(VI) oxide, aluminum trimethyl, phosphorus trioxide... 

Phthalic acid Piperazine Platinum Nitric acid, sodium nitrite Oxidizers Acetone, arsenic, hydrazine, lithium, proxosulfuric acid, phosphorus, selenium, tellurium... 

Nafion and PDDA [58]. Thermal treatment of the resulting films gave a mesoporous Ti02 matrix with Au NPs embedded within and dispersed on top of the Ti02 matrix. Only about 10% of the Au surface area was electrochemically active, suggesting that a large fraction of the Au NPs was not well coimected to the underlying electrode surface. These mesoporous deposits were shown to be effective electrocatalysts for NO and nitrite oxidation. 

Recent research suggests that denitrification may involve the reduction of nitrate to nitrite followed by the reaction of nitrite with ammonium in which the nitrogen in nitrite oxidizes the nitrogen in ammonium thereby generating a molecule of NjCg). This is termed the anammox reaction. 

The stepwise nature of nitrification during the aerobic decomposition of detrital PON is illustrated in Figure 24.6. Initially, the degradation of PON produces ammonium, which stimulates the growth of the nitrate oxidizers. These bacteria transform the ammonium into nitrite, causing ammonium concentrations to decline and nitrite concentrations to rise. The elevated nitrite levels stimulate the growth of the nitrite oxidizers. These bacteria transform the nitrite into nitrate. Eventually all of the DIN is oxidized to nitrate. The residual pool of PON includes microbial biomass and any PON too inert to be degraded by aerobic marine bacteria. 

The simplest dialkyl N-nitrosamines are relatively volatile, and airborne N-nitrosamines are to be expected in the vicinity of chemicals which are contaminated with nitrosamines. In situ, formation of N-nitrosamines would be expected to occur if amines were present in close proximity to nitrosating agents such as nitrite, oxides of nitrogen and C-nitro compounds. 

Nitrosyidisulfonic acid, reaction mechanisms, 22 129, 130 Nitrous acid, 33 103 decomposition, rate constants, 22 157 as oxidizing agent, 22 133 reaction mechanisms, 22 143-156 electrophilic nitrosations, 22 144-152 with inorganic species, 22 148, 149 nitrite oxidation by metals, 22 152-154 oxidation by halogens, 22 154, 155 in solution, 22 143, 144 reduction by metals, 22 155, 156 Nitrous oxide reductase, 40 368 Nitroxyl, reaction mechanisms, 22 138 Nitrozation, pentaamminecobalt(III) complexes, 34 181... 

An aluminum electrode modified by a chemically deposited palladium pen-tacyanonitrosylferrate film was reported in [33]. Vitreous carbon electrode modified with cobalt phthalocyanine was used in [34]. Electrocatalytic activity of nanos-tructured polymeric tetraruthenated porphyrin film was studied in [35]. Codeposition of Pt nanoparticles and Fe(III) species on glassy-carbon electrode resulted in significant catalytic activity in nitrite oxidation [36]. It was shown that the pho-tocatalytic oxidation at a Ti02/Ti film electrode can be electrochemically promoted [37]. 

Reshetelov AN, Iliasov PV, Knackmus HJ, Boronin AM (2000) The nitrite oxidizing activity of Nitrobacter strains as a base of microbial biosensor for nitrite detection. Anal Lett 33 29-41... 

Takenaka, N., A. Ueda, and Y. Maeda, Acceleration of the Rate of Nitrite Oxidation by Freezing in Aqueous Solution, Nature, 358, 736-738 (1992). 

C. Grundmann, P. Grunanger, The Nitrite Oxides. Springer, Berlin 1971. 

DiSpirito, A. A., and Hooper, A. B. (1986). Oxygen exchange between nitrate molecules during nitrite oxidation by Nitrobacter. J. Biol. Chem. 261, 10534-10537. 

Doyle, M. P., Pickering, R. A., daConcei5ao, J. (1984). Structural effects in alkyl nitrite oxidation of human hemoglobin. J. Biol. Chem. 259, 80-87. 

Phosphates, molybdates, and (at high pH) silicates act as anodic inhibitors much as do alkalis, except that the iron oxides/hydroxides formed on anodic sites then contain some PO43-, M0O42-, or Si044- ( basic iron phosphates, etc.). These inhibitors require the presence of 02 to produce basic iron(III) phosphate, molybdate, or silicate films, whereas oxidizing anions such as chromates and nitrites oxidize Fe2+ (aq) rapidly to insoluble iron(III) oxides on anodic sites. Dianodic inhibitors combine complementary inhibition mechanisms for example, sodium triphosphate may be used with sodium chromate, or sodium molybdate with NaN02. 

Acetoxylation of fS,y-unsaturated esters.3 / ,y-Unsaturated esters are oxidized by PdCI2-CuCl-02 to y-keto esters in 20 40% yield. Reaction of these esters with PdCl2 and KOAc and pentyl nitrite (oxidizes Pd(0)] under oxygen leads to y-aceloxy-a,/ -unsaturated esters (45- 55% yield). The double bond has the (reconfiguration (equation I). 

Nitrite oxidation to N03" following removal from the sampler can probably be minimized by freezing nylon (and other) filter samples immediately after collection and analyzing the aqueous filter extracts as soon as possible. 

PAN can be hydrolyzed quantitatively to N02 in alkaline solution. Thus, at least partial retention of PAN on alkali-coated denuders is likely. Ferm and Sjodin (42) reported up to 10% retention of PAN on an open-tube denuder coated with Na2C03. Facile conversion of N02 to N03 on carbonate-impregnated filters by oxidation with 03 has been reported (21), so similar conversion on alkali-coated denuders is likely. The use of glycerol in the alkaline denuder coating has been shown to decrease substantially the extent of nitrite oxidation (55). Slow oxidation of N02 to N03" in extracts of the denuder coating is also probable, a factor that can probably be minimized by low-temperature storage and by minimizing delays before analysis. 

Verdoheme Excess nitrite oxidizes porphyrin ring Ring opened Fe(III) Absent Green... 

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