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Acid Blue (acid + blue)
Selected AbstractsOn the Mechanism of Biotransformation of the Anthraquinonic Dye Acid Blue 62 by LaccasesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2009Luciana Pereira Abstract We used the recombinant CotA-laccase from the bacterium Bacillus subtilis to investigate the biotransformation of the commercial anthraquinonic dye Acid Blue 62. Kinetics of dye biotransformation at pH,6 follow a Michaelis,Menten model. NMR and several MS techniques allowed the identification of intermediates and final products of the enzymatic biotransformation. The main final product obtained, 1-[(4-amino-9,10-dioxo-3-sulfo-9,10-dihydroanthracen-1-yl)diazenyl]-4-cyclohexylamino-9,10-dioxo-9,10-dihydroanthracene-2-sulfonic acid, is formed through the creation of an azo link and has been previously identified as an intermediate compound in the biodegradation of Acid Blue 62 by crude fungal preparations. The identification of 1,4-diamino-9,10-dioxo-3-sulfo-9,10-dihydroanthracene-2-sulfonic acid and of cyclohexanone, in reaction mixtures with CotA-laccase and also its presence in reactions performed with the LAC3 laccase from the fungus Trametes sp. C30, suggest the occurrence of coupling reactions between the intermediate products of dye oxidation. Based on these results, we propose a mechanistic pathway for the biotransformation of Acid Blue 62 by laccases. A bioassay based on the inhibitory effects of the dye and its enzymatic products on the growth of Saccharomyces cerevisiae shows the importance of laccases in reducing dye toxicity. [source] Use of copper(II)/ethylene diamine-cotton complex for the adsorption of residual dyesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2007Mohamed Hassen V. Baouab Abstract The chemical modification of cotton is performed by successive reactions with thionyl chloride followed by ethylene diamine (ED) to prepare aminoalkyl amino cotton namely ED-cotton. Evidence of attaching ethylene diamine groups onto cotton is provided by nitrogen determination and thermogravimetry analysis. Because of complexation, the ethylene diamine-grafted groups immobilizes Cu(II) ions from buffered solution at pH 6. The formation of a 1/1 complex is assessed by the adsorption limit values. The binary system [Cu(II)/ED-cotton] is then tested for the adsorption of two acid dyes (Acid Blue 25 and Calmagite) as ligands in the metal-coordinating process. The adsorption of Cu(II) onto ED-cotton and of the dyes onto Cu(II)/ED-cotton is followed spectrometrically. The observed stoichiometries of the ternary-formed complex [Dye/Cu(II)/ED-cotton] are 1/1/1 with Acid Blue 25 and 0.75/1/1 with Calmagite at 20°C. The Langmuir and Freundlich isotherms constants for the adsorption of the tested dyes onto Cu(II)/ED-cotton are evaluated from the experimental data, but better agreement is obtained by using the composite isotherm of Jossens. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1389,1396, 2007 [source] Improved design and optimization models for the fixed bed adsorption of acid dye and zinc ions from effluentsJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 12 2002Danny C Abstract The bed depth service time (BDST) design model, which accounts for the change of bed adsorption capacity with service time, has been modified to expand its application and overcome the limiting assumptions of the original BDST analysis. Column experiments were undertaken to test the new model for two adsorption systems, namely zinc ion,bone char and Acid Blue 80 dye-activated carbon. It was found that the percentage of saturation capacity could be correlated using a square-root dependence on the service time and this correlation was incorporated into the original BDST analysis to replace the total sorption capacity term, giving the model a much wider application to real systems. The empty bed residence time optimization approach was modified using the same time-dependent capacity expression and was successfully applied to the metal ion,bone char and the dye-activated carbon system with the use of equilibrium saturated bed capacity. These modifications to the BDST design model and the EBRT optimization model will give more accurate scale-up data for the design of large-scale column adsorption systems. © 2002 Society of Chemical Industry [source] Comparison of negative ion electrospray mass spectra measured by seven tandem mass analyzers towards library formationRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 2 2008ina Volná A library of negative ion electrospray ionization mass spectra and tandem mass spectra (MS/MS) of sulfonated dyes has been developed for fast identification purposes. The uniform protocol has been elaborated and applied to the measurements of more than 50 anionic dyes. Three collision energies are selected in our protocol which ensures that at least one of them provides a suitable ratio of product ions to the precursor ion. The robustness is investigated with altered values of tuning parameters (e.g. the pressure of the nebulizing gas, the temperature and the flow rate of drying gas, and the mobile phase composition). The results of the inter-laboratory comparison of product ion mass spectra recorded on seven different tandem mass spectrometers (three ion traps, two triple quadrupoles and two hybrid quadrupole time of flight instruments) are presented for four representative anionic dyes , azo dye Acid Red 118, anthraquinone dye Acid Violet 43, triphenylmethane dye Acid Blue 1 and Al(III) metal-complex azo dye. The fragmentation patterns are almost identical for all tandem mass analyzers, only the ratios of product ions differ somewhat which confirms the possibility of spectra transfer among different mass analyzers with the goal of library formation. Copyright © 2007 John Wiley & Sons, Ltd. [source] Anodic oxidation of the dye materials methylene blue, acid blue 25, reactive blue 2 and reactive blue 15 and the characterisation of novel intermediate compounds in the anodic oxidation of methylene blueJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 7 2002John D Donaldson Abstract Anodic oxidation of the dye molecules, methylene blue, acid blue 25, reactive blue 2 and reactive blue 15 in chloride solution leads to colour destruction but UV and TOC data show that the oxidation reactions do not lead to complete destruction of the organic molecules. Analysis of the anodic oxidation products of [3,7-bis (dimethylamino) phenothiazinium] chloride (methylene blue) in a chloride solution provides evidence for formation of seven neutral and two charged intermediates. The main intermediate is identified by its X-ray diffraction crystal structure and accurate mass spectrometry as the novel leuco dye 4,6-dichloro-7-dimethylamino-3H -phenothiazin-3-one, C14H10Cl2N2OS (I) formed by replacement of one of the dimethylamino groups of methylene blue with oxygen accompanied by regiospecific chlorination of the carbocyclic systems. The mass spectra of other intermediates formed are interpreted in terms of the structure of I. © 2002 Society of Chemical Industry [source] | ||||||||||