Methylene green, oxidation with

Modified electrodes for this analytical purpose have mostly been formed by electrode adsorption of the mediator systems on the electrode surface or by electropolymerization [24,116]. Recently, for example, NAD(P)H oxidations have been performed on platinum or gold electrodes modified with a monolayer of pyrroloquinoline quinone (PQQ) [117] or on poly(methylene blue)-modified electrodes with different dehydrogenases entrapped in a Nafion film for the amperometric detection of glucose, lactate, malate, or ethanol [118]. In another approach, carbon paste electrodes doped with methylene green or meldola blue together with diaphorase were used for the NADH oxidation [119]. A poly(3-methylthio-phene) conducting polymer electrode was efficient for the oxidation of NADH [120]. By electropolymerization of poly(aniline) in the presence of poly(vinylsulfonate) counterions. 

It is prepared by oxidation of dimethylparaphenylenediamine-thiosulphonic acid (see Methylene Blue) with ethyl-methylaniline, and boiling the resulting insoluble green compound with zinc-chloride solution. A leuco-compound is formed, and is converted into dyestuff by oxidation. The commercial product forms a reddish-brown powder. 

Zhang, W., Tang, W.L, Wang, D.I.C., and Li, Z. (2011) Concurrent oxidations with tandem biocatalysts in one pot green, selective and clean oxidations of methylene groups to ketones. Chem. Commun., 47, 3284-3286. 

Based on AA oxidation to dehydroascorbic acid in acidic medium using iodine-iodide solution as oxidizing reagent. The iodine amount consumed in the redox reaction was detected Electrocatalysis of AA on a glassy carbon electrode chemically modified with polyaniline films AA was determined at a vitreous C electrode modified with 3,4-dihydroxybenzaldehyde AA was determined with a chemically modified with methylene green (electron mediator) carbon paste electrode... 

Redox films ean be produeed by electropolymerization of small redox molecules, whieh retain redox ehemistry in the polymerized state. The suggested structure of a polymerie version of poly (methylene blue) is shown in panel H of Table 9.1 [60]. In 1996, Zhou et al. demonstrated that methylene green could be electropolymerized on an electrode surface, resulting in a film with a half-wave potential in the vicinity of 0.21 V versus the standard hydrogen electrode (SHE) [100]. Furthermore, their work showed that this film eould mediate to NADH, reducing the required oxidation overpotential by 400 mV. Similar polymers have been demonstrated to mediate to NAD/NADH, sueh as poly(neutral red) [101]. 

Oxidation of AA with methylene green (MG) is accelerated when atmospheric oxygen is replaced with carbon dioxide. The reaction followed fractional order kinetics... 

A two-phase titration method for determining amine oxides in the presence of anionic surfactants calls for titration of the anionics first with benzethonium chloride at pH 9.5 using bromcresol green as indicator. A second aliquot of the sample is analyzed by adding exactly the amount of benzethonium chloride needed to complex the anionic surfactant. The amine oxide, with the ion pair of the anionic surfactant, is then extracted into chloroform at pH 9.5. The chloroform solution is mixed with water and titrated with alkyl-benzene sulfonate solution at pH 2 using methylene blue indicator (17). Another approach... 

At that time, our coatings were made in Towanda with methylene chloride as solvent, but our custom coating was done with butanone and isopropyl alcohol. The samples of TCTM-HABI had good solubility in this solvent pair. When Green precipitated the product from the oxidation of the 2,4-bis(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)imidazole, he made a startling discovery. Some of it went into solution in the ketone solvent, but most did not. What did... 

Although Pad 4 is oxidized by tropolone in oxygen-free methylene dichloride, the reaction between lithium tropolonate and the tetrachloride yields either PaT4 or LiPaTj, depending on the amount of LiT used. These blue-green, air-sensitive solids are isostructural with their thorium(IV) analogs (Brown and Rickard). Np(I V), in contrast to Th(IV), Pa(IV), and U(IV), does not form the pentakis lithium salt. This is... 

Perchlorate ions form extractable ion-associates with basic dyes such as Brilliant Green (e= 9.4-10 ) [34,35], Malachite Green [36,37], Crystal Violet [38], Methylene Blue [39], and the oxidized form of Variamine Blue [40]. Chloroform, dichloroethane, benzene, nitrobenzene and toluene have been used as extractants. Perchlorate impurities in potassium chlorate have been determined by these sensitive methods [34]. The FIA technique has been applied in the determinations [35]. 

Iodide ions (as F or I3 ) can be extracted as ion-pairs with basic dyes such as Crystal Violet [8,9], Brilliant Green [10,11], Rhodamine B (in toluene) [12], or Butylrhodamine (in benzene) [13]. After oxidation of iodide to iodine, the iodine is extracted into CCI4 and then stripped into the aqueous phase (as F) by shaking with thiosulphate. Finally, the F ions associated with Methylene Blue, are extracted into 1,2-dichloroethane [14]. 

Although La-ZSM-5 has been reported as a selective catalyst in the oxidation of phenol with N20 to give / -hydroquinone with a selectivity of 82.1% (Deng et al. 1997), Ce-containing microporous materials have been the most studied catalysts in redox processes. Thus, Ce-Y zeolite has been used in the complete oxidation of methylene chloride in air (Chatteijee and Greene 1991). However, Ce-modified zeolites can also be used in selective oxidation reactions. This is the case for the selective oxidation of /7-xylene at 130°C on Ce-containing Mordenite (Hasimoto et al. 1997) or the selective oxidation of cyclohexane on Ce-exchange Y (Pires et al. 1997). Recently, it has been... 

Greene [90] investigated the oxidative destruction of methylene chloride by zeolite Y in the H form and ion exchanged with cerium and chromium. The zeolite was supported on a low surface area cordierite honeycomb monolith by application as a wash coat. Below 425°C the catalytic activity decreased in the order ... 

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