Azo dyes, sulfonated

Goszczynski S, A Paszczynski, MB Pasti-Grigsby, RL Crawford, DL Crawford (1994) New pathways for degradation of sulfonated azo dyes by microbial peroxidases of Phanerochaete chrysosporium and Streptomyces chromofuscus. J Bacterial YIU. 1339-1347. 

Haug W, A Schmidt, B Nortemann, DC Hempel, A Stolz, H-J Knackmuss (1991) Mineralization of the sulfonated azo dye mordant Yellow 3 by a 6-aminonaphthalene-2-sulfonate-degrading bacterial consortium. Appl Environ Microbiol 57 3144-3149. 

CE is also potentially a useful alternative analytical tool for monitoring of chemicals (dyes, flame retardants and lubricants) involved in various steps of the textile fibre manufacturing process. In this area, CE compares favourably with existing techniques. CZE-MSn was used for the analysis of sulfonated azo dyes [942]. A variety of fluorescent analytes including thiazole orange dyes have been characterised by CE-FLNS [943]. 

Most dyes, including sulfonated azo dyes, are nonvolatile or thermally unstable, and therefore are not amenable to GC or gas-phase ionisation processes. Therefore, GC-MS techniques cannot be used. GC-MS and TGA were applied for the identification of acrylated polyurethanes in coatings on optical fibres [295]. Although GC-MS is not suited for the analysis of polymers, the technique can be used for the study of the products of pyrolysis in air, e.g. related to smoke behaviour of CPVC/ABS and PVC/ABS blends [263],... 

LC-TSP-MS without tandem mass capabilities has only met with limited success for additive analysis in most laboratories. Thermospray ionisation was especially applied between 1987 and 1992 in combination with LC-MS for a wide variety of compound classes, e.g. dyes (Fig. 7.31). Thermospray, particle-beam and electrospray LC-MS were used for the analysis of 14 commercial azo and diazo dyes [594]. No significant problems were met in the LC-TSP-MS analysis of neutral and basic azo dyes [594,595], at variance with that of thermolabile sulfonated azo dyes [596,597], LC-TSP-MS has been used to elucidate the structure of Basic Red 14 [598]. The applications of LC-TSP-MS and LC-TSP-MS in dye analysis have been reviewed [599]. 

Electrospray has been successful for numerous azo dyes that are not ionic salts. Several anthraquinone dyes have been analysed by LC-ESI-MS [552]. Electrospray achieves the best sensitivity for compounds that are precharged in solution (e.g. ionic species or compounds that can be (de)protonated by pH adjustment). Consequently, LC-ESI-MS has focused on ionic dyes such as sulfonated azo dyes which have eluded analysis by particle-beam or thermospray LC-MS [594,617,618]. Techniques like LC-PB-MS and GC-MS, based on gas-phase ionisation, are not suitable for nonvolatile components such as sulfonated azo dyes. LC-TSP-MS on... 

Azo toner pigments provide the standard worldwide process magenta colorants for printing inks. Cl Pigment Red 57 1 (33), known as Calcium 4B toner, is one of the most important. These pigments were considered as insoluble calcium (or barium) salts of the sulfonated azo dye... 

Industrial wastewater containing precursors and synthesis products of 15 sulfonated azo dyes Anaerobic baffled reactor containing mixed sulfate reducing bacteria, and methanogens In an anaerobic baffled reactor, almost a complete removal of color was observed in the reactor within 100 days of operation [182]... 

Vijaykumar MH, Vaishampayan PA, Shouche YS, Karegoudar TB (2007) Decolourization of naphthalene-containing sulfonated azo dyes by Kerstersia sp. strain VKY1. Enz Microbial Technol 40 204-211... 

Kudlich M, Hetheridge MJ, Knackmuss HJ, Stolz A (1999) Autoxidation reactions of different aromatic o-aminohydroxynaphthalenes that are formed during the anaerobic reduction of sulfonated azo dyes. Env Sci Technol 33 869-901... 

Suzuki T, Timofei S, Kurunczi L et al (2001) Correlation of aerobic biodegradability of sulfonated azo dyes with the chemical structure. Chemosphere 45 1-9... 

FitzGerald SW, Bishop PL (1995) Two stage anaerobic/aerobic treatment of sulfonated azo dyes. J Env Sci Health 30 1251-1276... 

Kudlich M, Bishop P, Rnackmuss H-J et al (1996) Synchronous anaerobic and aerobic degradation of the sulfonated azo dye Mordant Yellow 3 by immobilized cells from a naphthalenesulfonate-degrading mixed culture. Appl Microbiol Biotechnol 46 597-603... 

Sulfonated azo dyes are widely used in different industries [16]. Some structure of sulfonated and unsulfonated azo dyes is shown in Fig. 1. These water-soluble azo dyes will enter the environment generally with wastewater discharge. Also, these sulfonated and unsulfonated azo dyes have a negative aesthetic effect on the wastewater, and some of these compounds and biodegraded products are also toxic, carcinogenic, and mutagenic [17]. There exists clear evidence that sulfonated azo dyes show decreased or no mutagenic effect compared to unsulfonated azo dyes... 

Paszczynski A, Pasti-Grigsby MB, Goszczynski S et al (1992) Mineralization of sulfonated azo dyes and sulfanilic acid by Phanerochaete chrysosporium and Streptomyces chromofuscus. Appl Environ Microbiol 58 3598-3604... 

Diniz PE, Lopes AT, Lino AR (2002) Anaerobic reduction of a sulfonated azo dye Congo Red by sulphate reducing bacteria. Appl Biochem Biotechnol 97 147-163... 

To reach the reductive step of the azo bond cleavage, due to the reaction between reduced electron carriers (flavins or hydroquinones) and azo dyes, either the reduced electron carrier or the azo compound should pass the cell plasma membrane barrier. Highly polar azo dyes, such as sulfonated compounds, cannot pass the plasma membrane barrier, as sulfonic acid substitution of the azo dye structure apparently blocks effective dye permeation [28], The removal of the block to the dye permeation by treatment with toluene of Bacillus cereus cells induced a significant increase of the uptake of sulfonated azo dyes and of their reduction rate [29]. Moreover, cell extracts usually show to be more active in anaerobic reduction of azo dyes than whole cells. Therefore, intracellular reductases activities are not the best way to reach sulfonated azo dyes reduction the biological systems in which the transport of redox mediators or of azo dye through the plasma membrane is not required are preferable to achieve their degradation [13]. 

The reductive cleavage of sulfonated azo dyes by several bacterial strains in aerobiosis and in the presence of other carbon and energy sources has been observed [22, 32-36]. 

Mechsner K, Wuhrmann K (1982) Cell permeability as a rate limiting factor in the microbial reduction of sulfonated azo dyes. Eur J Appl Microbiol Biotechnol 15(2) 123-126... 

M. Perez-Urquiza, R. Ferrer and J.L. Beltran, Determination of sulfonated azo dyes in river samples by capillary zone electrophoresis. J. Chromatogr.A, 883 (2000) 277-283. 

Sh. Agarwal, Ph. Cluxton, M. Kemper, D.D. Dionysiou, S.R. Al-Abed, Assessment of the functionality of a pilot-scale reactor and its potential for electrochemical degradation of calmagite, a sulfonated azo-dye, Chemosphere, 73, 837-843 (2008). 

The first work on pKa determination by zone electrophoresis using paper strips was described by Waldron-Edward in 1965 (15). Also, Kiso et al. in 1968 showed the relationship between pH, mobility, and p/C, using a hyperbolic tangent function (16). Unfortunately, these methods had not been widely accepted because of the manual operation and lower reproducibility of the paper electrophoresis format. The automated capillary electrophoresis (CE) instrument allows rapid and accurate pKa determination. Beckers et al. showed that thermodynamic pATt, (pATf) and absolute ionic mobility values of several monovalent weak acids were determined accurately using effective mobility and activity at two pH points (17). Cai et al. reported pKa values of two monovalent weak bases and p-aminobenzoic acid (18). Cleveland et al. established the thermodynamic pKa determination method using nonlinear regression analysis for monovalent compounds (19). We derived the general equation and applied it to multivalent compounds (20). Until then, there were many reports on pKa determination by CE for cephalosporins (21), sulfonated azo-dyes (22), ropinirole and its impurities (23), cyto-kinins (24), and so on. 

M Perez-Urquiza, JL Beltran. Determination of the dissociation constants of sulfonated azo dyes by capillary zone electrophoresis and spectrophotometry methods. J. Chromatogr. A 917 331-336 (2001). 

SPE methods with different cartridge packings have been employed for the pre-concentration and clean up of sulfonated azo dyes from waters and soil extracts [110,111], The extraction of solid samples has been carried ont by sonication or Soxhlet extraction and the extracts treated like the water samples. C18 cartridges and columns [111] were used followed by the elution with aqueous organic solvents in the presence of TEA with recovery yields always greater than 65% [93,111], Higher recoveries have been obtained by using C18 columns, pre-conditioned with an ammonium acetate buffer and elnted with methanol [111], The use of styrene-divinylbenzene [93,112], as well as of cross-linked polymeric sorbents with sulfonate functions, was shown to be suitable in the SPE of the more polar componnds [111],... 

The potentiality in the identification process [127] is increased by fragmentation experiments. A review reports the more recent analytical LC/MS methods suitable for the determination of snlfonated dyes in the efflnents [45], Atmospheric pressure ionization techniques are frequently nsed in the identification and the determination of sulfonated azo dyes [46,95,111,128,129] and their... 

The interaction of metallochromic indicators (Section 10.6.4) with metals has received a lot of attention since the resulting complexes are often solvent extractable. C. Woodward and H. Freiser73 have examined complexes of metals with sulfonated azo dyes with a view to their extraction by Aliquat-336. Vanadium in sea water can be determined at the 2 p.p.b. level by complexation with PAR (4-(2-pyridylazo)resorcinol) in the presence of CDTA and extracting the anion so formed into Zephiramine (tetradecyldimethylbenzylammonium chloride).74 The field has been reviewed up to 1971 by Ueno.2... 

Sulfonated azo dyes (reactive dyes) are widely used in the textile industry. Due to the simultaneous hydrolysis in the dyeing process, 15-60 % of the reactive dyes reach the waste water system. In addition, their use strongly increases with the colouring of natural fibres, and so a total of 60 % of all dyes emitted to the waste water are reactive materials. 

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