64 resultados para Permanganate-periodate

em Deakin Research Online - Australia


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A critical review presented is of the literature concerning the use of acidic solutions of potassium permanganate to generate chemiluminescence during the oxidation of both organic compounds and inorganic species. A brief overview of the reagent’s historical origin is followed by a chronological survey of its analytical applications, from what we believe to be the first report in 1975 through to those published up until mid-2001. This review does not include those papers where potassium permanganate has been used either in alkaline conditions or in conjunction with other chemiluminescence reagents.

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Flow injection methodology is described for the estimation of the total phenolic content of wine using acidic potassium permanganate chemiluminescence detection. Selected simple phenolic compounds including quercetin, rutin, catechin, epicatechin, ferulic acid, caffeic acid, gallic acid, 4-hydroxycinnamic acid and vanillin elicited analytically useful chemiluminescence with detection limits ranging between 4×10−10 and 7×10−7 M. A comparison between the chemiluminescence methodology and other total phenol/antioxidant assays, used by the food and beverage industry, resulted in a good correlation. The chemiluminescence detection was found to be selective with minimal interferences being observed from the non-phenolic components in wine. Analysis of 12 different wines showed that the chemiluminescence method was a rapid way to estimate their antioxidant or total phenolic content.

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The limits of detection (3s) for ascorbic acid were 5×10−8 M with acidic potassium permanganate using both flow injection analysis (FIA) and sequential injection analysis (SIA) whereas the soluble manganese(IV) afforded 1×10−8 M and 5×10−9 M for FIA and SIA, respectively. Determinations of ascorbic acid in Vitamin C tablets were achieved with minimal sample pretreatment using a standard additions calibration and gave good agreement with those of iodimetric titration.

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This paper describes a dual chemiluminescence reagent for the determination of the opiate alkaloids morphine, codeine, oripavine, and thebaine in Papaver somniferum extracts. Detection was achieved using a mixture of acidic potassium permanganate and tris(2,2′-bipyridyl)ruthenium(ii), where the former acted as both the oxidant for the latter and as a chemiluminescence reagent in its own right. The analytes were separated on a C8 column using ion-pairing HPLC. The application of the mixed reagent detection compared favourably with results obtained using standard HPLC methodology. Detection limits for the alkaloids were 10-6, 5 × 10-7, 3 × 10-6, and 2 × 10-6 mol L-1 for morphine, codeine, oripavine, and thebaine, respectively.

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For the first time, analytically useful chemiluminescence was elicited from the reactions of the pyrrolizidine alkaloids. Heliotrine, retronecine, supinine, monocrotaline and echinatine N-oxide yielded chemiluminescence upon reaction with tris(2,2′-bipyridyl)ruthenium(II) whilst lasiocarpine, its N-oxide and supinine elicited light upon reaction with acidic potassium permanganate. Detection limits for heliotrine were 1.25 × 10−7 M and 9 × 10−9 M for tris(2,2′-bipyridyl)ruthenium(III) perchlorate with flow injection analysis (FIA) and the silica-immobilised reagent (4-[4-(dichloromethylsilanyl)-butyl]-4′-methyl-2,2′-bipyridine)bis(2,2′-bipyridyl)ruthenium(II) with sequential injection analysis (SIA), respectively. Lasiocarpine was detectable at 1.4 × 10−7 M using acidic potassium permanganate with FIA. Additionally, the silica-immobilised reagent was optimised with respect to the oxidant (ammonium ceric nitrate) concentration and the aspiration times which afforded a detection limit for codeine of 5 × 10−10 M using SIA.

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A simple, rapid and sensitive method for the determination of psilocin and psilocybin is described. This is the first report on the determination of psilocin and psilocybin using flow injection analysis with acidic potassium permanganate and tris(2,2′-bipyridyl)ruthenium(II) chemiluminescence. The limits of detection (signal-to-noise ratio = 3) are 9 × 10−10 M and 3 × 10−10 M for psilocin and psilocybin, respectively.A concise synthetic route for psilocin in three steps from readily available starting materials is also described. The structures were elucidated on the basis of spectroscopic data.

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When aqueous sodium borohydride (50 mM) is added to a solution of potassium permanganate (1mM, in sodium hexametaphosphate) at acidic pH, bright red-orange emission is easily visible in a darkened room. This chemiluminescence emission is due to an excited state of manganese (II) that undergoes solution phase phosphorescence and provides an excellent opportunity for students to explore the relationship between the initial oxidation state of the manganese and the likelihood of luminescence. Not surprisingly Mn(VII), Mn(IV) and Mn(III) all give rise to chemiluminescence where as Mn(II) fails to react.

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This paper describes a procedure for the determination of psilocin and psilocybin in mushroom extracts using high-performance liquid chromatography with postcolumn chemiluminescence detection. A number of extraction methods for psilocin and psilocybin in hallucinogenic mushrooms were investigated, with a simple methanolic extraction being found to be most effective. Psilocin and psilocybin were extracted from a variety of hallucinogenic mushrooms using methanol. The analytes were separated on a C12 column using a (95:5% v/v) methanol:10 mM ammonium formate, pH 3.5 mobile phase with a run time of 5 min. Detection was realized through a dual reagent chemiluminescence detection system of acidic potassium permanganate and tris(2,2'-bipyridyl)ruthenium(II). The chemiluminescence detection system gave improved detectability when compared with UV absorption at 269 nm, with detection limits of 1.2 × 10−8 and 3.5 × 10−9 mol/L being obtained for psilocin and psilocybin, respectively. The procedure was applied to the determination of psilocin and psilocybin in three Australian species of hallucinogenic mushroom.

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A critical and comprehensive review of acidic potassium permanganate chemiluminescence is presented. This includes discussion on reaction conditions, the influence of enhancers such as polyphosphates, formaldehyde and sulfite, the relationship between analyte structure and chemiluminescence intensity, and the application of this chemistry to determine a wide variety of compounds, such as pharmaceuticals, biomolecules, antioxidants, illicit drugs, pesticides and pollutants. Previous proposals for the nature of the emitting species are re-evaluated in light of recent evidence.

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Adrenergic amines found in extracts of Citrus aurantium (bitter orange) evoke analytically useful chemiluminescence with acidic potassium permanganate in the presence of polyphosphates. From corrected chemiluminescence spectra, the wavelength of maximum intensity for these reactions was 680 ± 5 nm and, using flow injection analysis methodology, limits of detection for synephrine, octopamine, tyramine and hordenine were found to be between 1 × 10−9 and 1 × 10−8 M. We have applied this method of detection to the rapid determination of synephrine in dietary supplements using monolithic column chromatography.

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A direct comparison of the laser-induced photoluminescence of manganese(II) with the chemiluminescence from the reaction between acidic potassium permanganate and sodium borohydride was used to confirm that the characteristic red emission from this widely used chemiluminescence reagent emanates from an electronically excited manganese(II) species.

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The reaction of acidic potassium permanganate with a wide range of compounds is known to produce a broad red emission, and there is strong evidence for an excited manganese(II) emitting species. Nevertheless, numerous researchers have proposed other emitters for reactions with acidic potassium permanganate, particularly for systems where fluorescent compounds were present, either as enhancers or reaction products. We have examined many reactions of this type and found that, in most cases, the same red emission was produced. There were, however, some exceptions, including the oxidation of dihydralazine, certain thiols and sulphite (each in the presence of an enhancer).

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There is great interest in the activity of antioxidant molecules, including polyphenols, from food and plant sources. Acidic potassium permanganate chemiluminescence signal intensity was shown to predict the ability of polyphenols to positively act on cellular redox state and attenuate oxidative stress in cultured skeletal muscle cells.