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Introduction Dyes are compounds that are widely used in textile, paper, plastic and cosmetic industries and are easily recognized as pollutants [ 1 ]. Methylene blue (MB) is a heterocyclic aromatic chemical compound. It has
. McBride , T. J. , Schneider , J. E. , Floyd , R. A. , Loeb , L. A. ( 1992 ) Mutations induced by methylene blue plus light in single-stranded M13mp2 . Proc. Natl. Acad. Sci. USA 89 , 6866 – 6870 . 15
iron(II) on a NaY zeolite as a heterogenous photo-Fenton catalyst for the degradation of methylene blue (MB) used as a dye model pollutant under λ > 420 nm visible light irradiation and studied the kinetics of photo-Fenton degradation of this dye after
Abstract
A method has been developed for the extraction of rhenium/VII/ with methylene blue. Nitrobenzene was found to be the most effective extractant for Re/VII/. The stoichiometry of metal to reagent determined by the method of substoichiometric extraction and slope-ratio method was found to be 1
1.
Abstract
Investigation on electrophilic attaching of astatine-211 to methylene blue is carried out. Conditions for transferring astatine to a chemically active electrophilic form were found. A method for the production of astatine-211-tagged methylene blue has been developed. The resulting radiopharmaceutical preparation is free of the nonisotopic iodine carrier. The chromatographic method of purifying simultaneously the product by anion-exchange resin QAE-Sephades A-25 allows it to pass into a 0.9% solution of sodium chloride (physiological salt solution). The method provides the radiochemical yield of astatine-211-tagged methylene blue as large as 68±6%.
Abstract
A spectrophotometric study is reported of the reduction of some dyes having the methylene blue structure used in bacteriological staining. The reduction is effected by the species liberated during the dissolution of 
-irradiated sodium chloride, in the same way as by direct low -dose. The G values for the two modes of the reduction are compared and the effects of radical scavengers on the reactions are studied. Results are found to be similar to the chemically and biologically induced reductions. The dyes studied include besides Methylene Blue, Janus Green B and Nile Blue sulfate.
Abstract
The extraction of99mtechnetium/VII/ with methylene blue into organic solvent has been investigated. Nitrobenzene, which was found to be the most effective extractant for99mTc/VII/, was used to separate99mTc/VII/ from other elements. The effect of various parameters on the extraction coefficient value such as effect of pH, time of equilibration, effect of anions and cations on the E value have been evaluated. The stoichiometry of metal to reagent was determined by the slope ratio method and was found to be 11.
Abstract
Methylene blue degradation has been studied spectrophotometrically in alkaline and alkaline peroxide solutions. In both systems, the reaction proceeds via successive N-demethylation and deamination steps determined applying TLC and HPLC techniques. Disappearance of the dye obeys first-order kinetics under the excess of all other reactants. The rate expression for the hydrolytic process (in the absence of hydrogen peroxide) is as follows: –d[MB]/dt = (b[OH–]/(1 + c[OH–]))[MB]. Analogous forms of the reaction rate dependence on [OH–] (at constant hydrogen peroxide concentration) and on [HO2 −] (at constant OH− ion concentration) are observed: –d[MB]/dt = ((a′ + b′[OH–])/(1 + c′[OH–]))[MB] and –d[MB]/dt = ((a″+ b″[HO2 –])/(1 + c″[HO2 –]))[MB], respectively. A higher-order than linear dependence of the pseudo first-order rate constant on the nucleophiles (OH– and/or HO2 –) concentrations results from the competitive formation of the ion pair of the cationic dye with the chloride of the supporting electrolyte and adducts of the dye with OH– and/or HO2 – anions.
Abstract
Heavy radiohalogenated derivatives of methylene blue of potential value as possible diagnostic and endoradiotherapeutic agents for malignant melanoma, have been synthesized by both electrophilic and nucleophilic reaction routes. Thermal halogen isotope exchange in molten crown ether catalyst facilitated the rapid preparation of high specific activity radioiodinated and [211At]-astatinated derivatives; radiochemical yields were in the order of 60–79%. Radiohalogenation mediated by chloramine-T or via diazonium intermediary proved more laborious, far less efficient and inappropriately is only suited to the preparation of low specific activity product.
