- Email: [email protected]
The process of the reduction of azo dyes used in dyeing textiles on the basis of infrared spectroscopy analysis
Journal of Molecular Structure 511–512 (1999) 337–344 www.elsevier.nl/locate/molstruc
The process of the reduction of azo dyes used in dyeing textiles on the basis of infrared spectroscopy analysis A. Pielesz* Textile Institute, Technical University of L⁄o´dz, ul Willowa 2, 43-309 Bielsko-Bial⁄a, Poland Received 24 October 1998; received in revised form 21 December 1998; accepted 21 December 1998
Abstract Nowadays the world observes a widespread campaign against the use in yarn of dangerous, carcinogenic amines which penetrate human organisms. Their source in organisms is the process of biological reduction of azo dyes which are used in dyeing yarn. The current obligatory methods of aromatic amine identification are the widely understood chromatographic methods. In this work, the identification of amines through the fourier transform infrared spectroscopy has been suggested. The results of the experiments have allowed the use of the same method in aromatic amine identification. q 1999 Elsevier Science B.V. All rights reserved. Keywords: MAK amines (Maximale Arbeintsplatz Konzentration); Fourier transform infrared spectroscopy; Qualitative identification of amines
1. Introduction During the past few years the public has become increasingly aware of environmental topics. Especially in the case of objects of daily life, such as yarn, attention is paid more and more to their environmental compatibility. Publications in the press have brought forward presumptions that yarn can cause danger to people’s health. These can be residues of combing, spinning or sizing agents, but above all dyestuffs, formaldehyde, chloroorganic compounds, mothproofing and antimicrobal agents. It is claimed that textile chemicals not only act as allergens but also exhibit toxic and even mutagenic or carcinogenic properties [1]. The sources of the mutagenic activity were the * Tel.: 1 48 33 822 9224; fax: 1 48 33 812 3502. E-mail address: [email protected] (A. Pielesz)
dyestuffs applied [2,3]. It is obvious that the dyestuffs themselves provide only a minor part of the mutagenic potential. In textile dyeing usually 80% of the dyestuffs are azo dyes. Some of these dyes may cleave-off under reducing conditions emitting aromatic amines which proved carcinogenic in animal experiments. The process of the reduction of azo dyes with the cleavage of aromatic R–NH2 amines is one of the ways of the degradation of those dyes. The others (Fig. 1) are: photodegradation and biodegradation by means of hydroxylation, oxidation, hydrolysis. However, in human organisms, it is the biological reduction of the azo dye that is responsible for the possible presence of the toxic amine in the organisms. Aromatic amines are specified [4,5] in the groups III A1 or III A2 of the Maximale Arbeintsplatz Konzentration (MAK) list as well as in IARC (International Agency for Research on Cancer) and ETAD (Ecological and Toxicological Association of the
0022-2860/99/$ - see front matter q 1999 Elsevier Science B.V. All rights reserved. PII: S0022-286 0(99)00176-3
338
A. Pielesz / Journal of Molecular Structure 511–512 (1999) 337–344
Fig. 1. Schematic model of the degradation of azo dyes [1].
Dyestuffs Manufacturing) lists (Table 1). The capability to form any of the above listed carcinogenic amines through cleavage of one or more azo groups is the reason why they all fall under the category of Table 1 The list of MAK amines MAK amines MAK III A1
MAK III A2
Nr CAS Benzidine 4-Aminodiphenyl 4-Chloro-o-toluidine 2-Naphtyloamine o-Aminoazotoluene 2-Amino-4-nitrotoluene p-Chloroaniline 2,4-Diaminoanisole 4,4 0 -Diaminodiphenylomethane 3,3 0 -Dichlorobenzidine 3,3 0 -Dimethoxybenzidine (odianisidine) 3,3 0 -Dimethylobenzidine (otolidine) 3,3 0 -Dimethyl-4,4 0 diaminodiphenylmethane p-crezidine 4,4 0 -Methyleno-bis-(2chloroaniline) 4,4 0 -Oxydianiline 4,4 0 -Tiodianiline 2-methylaniline (o-toluidine) 2,4-Toluylendiamine 2,4,5-Trimethylaniline
92-87-5 92-67-1 95-69-2 91-59-8 97-56-3 99-55-8 106-47-8 615-05-4 101-77-9 91-94-1 119-90-4 119-93-7 838-88-0 120-71-8 101-14-4 101-80-4 139-65-1 95-53-4 95-80-7 137-17-7
banned azo dyes. The import and marketing of corresponding textile and leather goods in Germany are likewise forbidden (the ban introduced in April 1996) [6]. The stringent regulation has made German buyers very sceptical of purchasing goods from their Asian business counterparts. I would like to add that in India, although the ban on benzidine was introduced two years ago, the use and manufacture of benzidine continued until recently due to its low cost [7]. The banned amines must be formed on reduction of the azo groups and not by other decomposition reactions under stronger conditions of analysis. The modification of the ordinance is based on the fact that it should cover only those bioavailable azo dyes which are likely to be split by enzymes in organisms. During exchange, the reductases in liver or intestinal bacteria can split only azo groups and not other bonds [8,9]. The association of consumers for eco-friendly yarn, published the method and it is obligatory with TLC, HPLC, or GC/MS techniques [4,10,11]. In the present study MAK amines were analysed by FT-IR spectroscopy.
2. Experimental Two methods of chemical reduction were adopted. More drastic conditions of the reduction process [12] involved: 1 g of yarn or 0.06 g of dye (i.e. the quantity fitting to standard of 3% dyeing). The sample was
A. Pielesz / Journal of Molecular Structure 511–512 (1999) 337–344
339
Fig. 2. The azo dye Direct Black 38 and the product of the reduction of Direct Black 38 benzidine.
heated in boiling temperature with 1 M NaOH for 1 h, after 30 min 0.6 g sodium dithionite was added (p.a. Sigma–Aldrich). Under less drastic conditions of reduction [13], the reduction was carried out at 708C at pH 6 using a citrate buffer with 0.6 g sodium dithionite per gram of fibre. The extract was transferred to Extrelut 20 columns into dichloromethane absolute (Merck). According to Ref. [12] methanol or acetic acid methyl ester was used for extraction. Identification of amines in artificial sweat was performed basing on the standard: PN-91/P-04913 (eqv ISO 105-E04/96). The FT-IR spectra of the pure components, samples were recorded on a Magna 860 Nicolet spectrometer. The following conditions were used: spectral resolution 4 cm 21, number of scans 50, collimator of beams.
3. Results and discussion It is known that every compound can be described by its characteristic IR spectrum. This kind of analysis has been carried out [14] before by means of a
comparison of aromatic amines standard. In the current study carcinogenic MAK amines were sought in the samples of azo dyes and yarn which had previously been subjected to a process of chemical reduction with sodium dithionite. The analysed samples of yarn were those dyed with benzidine dyes Figs. 2 and 3). Direct Black 38 and Direct Brown 95 dyes are typical direct dyes used in dyeing textiles and cotton yarn. Yarn dyed with the above dyes was subjected to a chemical reduction [13] in order to observe the process of reconstruction of the MAK amine, which in this case was benzidine, after the reduction of the dye. Fig. 4 presents a comparative analysis of the standard of MAK amine benzidine and benzidine, the product of the reduction of yarn dyed with Direct Black 38 and Direct Brown 95. A good comparative range is the spectral range of 2000–600 cm 21. After the chemical reduction of the dyestuffs, the following bands were reconstructed well: vibrations of the N–H deformating bands for R–NH2 amines (1650– 1590 cm 21), doublet of CyC skeletal vibrations of the aromatic ring (1450–1510 cm 21), C–N stretching vibrations (1180–1360 cm 21) and N–H deformating
Fig. 3. The azo dye Direct Brown 95 and the product of the reduction of Direct Brown 95-benzidine.
340
A. Pielesz / Journal of Molecular Structure 511–512 (1999) 337–344
Fig. 4. Comparison of the spectra of standard benzidine with the samples: (a) benzidine; (b) benzidine-the product of the reduction of yarn dyed with Direct Black 38; (c) benzidine-the product of the reduction of yarn dyed with Direct Brown 95.
vibrations (793–840 cm 21). However, in the range of 3700–2000 cm 21, an outline of vibrations can be detected, those which are attributed to the range of N–H stretching bands for R–NH2 amines (t 3400 cm 21).
A comparison of the reproducibility of MAK amine o-tolidine was carried out, later depending on the chemical reduction method. The Direct Orange G dye was applied. It is used in dyeing cotton and during reduction it reconstructs o-tolidine (Fig. 5). In the full
A. Pielesz / Journal of Molecular Structure 511–512 (1999) 337–344
341
Fig. 5. The azo dye-Direct Orange G and the product of the reduction of Direct Orange G-o-tolidine.
analytic range (Fig. 6) (3700–600 cm 21) good reproducibility of o-tolidine after reduction can be reported, regardless of whether the process was carried out in less or more drastic conditions of chemical reduction (708C, buffer, pH 6; and boiling temperature, 1 M NaOH, respectively). The fact that the chemical process is carried out in 1 M NaOH allows a complete reconstruction of that sought for the MAK amine. There is a risk, however, that the reconstructed amine is not formed as a result of the reduction of azo groups, but of some other undesirable re-grouping. In order to approximate the process of the chemical reduction to the process of enzyme reduction which takes place in human organisms, and to prevent untrue positive results (which means the presence of amines), the norms which are currently obligatorily recommended that this process should be carried out in less drastic chemical conditions [13]. In the samples (Fig. 6) the range of the vibrations of N–H stretching bands for aromatic amines (3500–3300 cm 21) is clearly discernible. The precise visibility of this range allows the application of the extracting column Extrelut 20. This observation is particularly significant because of the analytic conditions recommended by German standards. Chemical reduction carried out at a temperature of 708C, with the specified pH conditions for the environment, aims at approximating the chemical process to the conditions which are to take place in vivo. Another resemblance to actual conditions, i.e. the contact of dyed textile with human skin, is treating the dyestuff with artificial sweat (Fig. 7). Artificial sweat containing: l-histidine monohydrochloride monohydrate, NaCl, Na2HPO4 or NaH2PO4 where by the means of NaOH its pH was made to equal
pH 8 or pH 5.5, is a commonly accepted norm in the textile industry used in identifying the durability of the dye. The obtained spectra (Fig. 7), which are the result of the reaction of azo dye with artificial sweat, do not give a satisfactory answer to the problem of the reconstruction of the sought for carcinogenic MAK amine. Application of the TLC method produces similar results. [15] What proves it is mainly the lack of the bands t 3400 cm 21 which are characteristic to R– NH2 amine. The range of 2000–600 cm 21 does not correspond with the bands characteristic to o-tolidine either. In this way, the problem of the penetration of carcinogenic MAK amines into the insides of human organisms through the skin (through contact with sweat) still remains open. However, it is known that people involved in making benzidine dyes and in danger of contact with increased concentration of benzidine suffered from cancer of the bladder [16,17]. However, until now, it has not been fully proved that wearing clothing dyed with azo dyes cleaving under reduction of amine, leads to such a type of cancer. It follows from this work that the process of the reduction of dye in buffer (pH 6) cannot be satisfactorily compared with the reaction of dye with artificial sweat (pH 5.5 or 8). The presented results of research with the use of FT-IR spectroscopy to identify MAK amines are of pilot character and will be extended in consecutive papers mainly by the quantitative analysis of MAK amines.
4. Conclusions Figs. 4, 6 and 7 illustrate a number of spectroscopic analyses of MAK amines. Similar dependencies can
342
A. Pielesz / Journal of Molecular Structure 511–512 (1999) 337–344
Fig. 6. Comparison of the spectra of standard o-tolidine with the samples: (a) o-tolidine; (b) o-tolidine-the product of the reduction of dye Direct Orange G in NaOH; (c) o-tolidine-the product of the reduction of dye Direct Orange G in citrate buffer.
be observed in other amines and azo dyes, which are capable of a reductive split of MAK amines. The presented results of the research work using FT-IR spectroscopy can constitute a competitive method of analysis to the currently recommended chromatographic methods (especially TLC).
Acknowledgements The author wishes to thank M.S.W. Binis´ for technical assistance in the analyses of MAK amines. This work was supported by KBN Poland, Grant no 7 TO8E 033 14.
A. Pielesz / Journal of Molecular Structure 511–512 (1999) 337–344
343
Fig. 7. Comparison of the spectra of o-tolidine standard with the samples: (a) o-tolidine; (b) D. Orange treated with acid sweat; (c) D. Orange treated with alkaline sweat.
References [1] R. Anliker, JSDC 9 (1979) 317. [2] G. Pfizenmaier, Natur 9 (1990) 71. [3] G. Pfizenmaier, T. Pflaum, Natur 3 (1995) 40.
[4] Zweite Verordung zur Anderung, Bundesgesetzblatt, Jahrgang 15 (7) (1994) Teil I. [5] Vierte Verordrung zur Anderung der Bedarfsgegenstandenverordnung, Bundesgesetzblatt, Jahrgang 20 (7) (1995) Teil I.
344
A. Pielesz / Journal of Molecular Structure 511–512 (1999) 337–344
[6] Dritte Verordung zur Anderung der Bedarfsgegenstandenverordnung vom16 Dezember 1994, Bundesgesetzblatt, Jahrgang (1994) Teil I.N.R.F. [7] Technical Support Staff (AG), Colourage 9 (1996) 19. [8] K.T. Chung, Mutation Research 114 (1983) 269. [9] S.W. Collier, J.E. Storm, R.L. Bronaugh, Toxicology and Applied Pharmacology 118 (1993) 73. [10] E. Idaka, T. Ogawa, JSDC 3 (1978) 91. [11] B. Ku¨ster, U. Wahl, Textilveredlung 32 (5/6) (1997) 121. [12] A. Wilken, B.M. Mu¨ller, J. Pieler, H. Ho¨cker, The Ninth
[13] [14]
[15] [16] [17]
International Textile Research Conference, Biella, Italy, 1995, p. 263. W.B. Achwal, Colourage 5 (1997) 29. A. Pielesz, W. Binias´, A. Włochowicz, The Second International Conference, Ło´dz´-Arturo´wek, Poland, 23–24 June 1998, p. 12. A. Pielesz, S. S´wierczek, A. Włochowicz, I. Baranowska, J. Planar. Chromatogr. 12 (1999) 215. G.M. Matanoski, E.A. Elliot, Epidemiol. Rev. 3 (1981) 203. J.A. Indulski, W. Lutz, Pol. J. Occup. Med. 5 (2) (1992) 143.
The process of the reduction of azo dyes used in dyeing textiles on the basis of infrared spectroscopy analysis A. Pielesz* Textile Institute, Technical University of L⁄o´dz, ul Willowa 2, 43-309 Bielsko-Bial⁄a, Poland Received 24 October 1998; received in revised form 21 December 1998; accepted 21 December 1998
Abstract Nowadays the world observes a widespread campaign against the use in yarn of dangerous, carcinogenic amines which penetrate human organisms. Their source in organisms is the process of biological reduction of azo dyes which are used in dyeing yarn. The current obligatory methods of aromatic amine identification are the widely understood chromatographic methods. In this work, the identification of amines through the fourier transform infrared spectroscopy has been suggested. The results of the experiments have allowed the use of the same method in aromatic amine identification. q 1999 Elsevier Science B.V. All rights reserved. Keywords: MAK amines (Maximale Arbeintsplatz Konzentration); Fourier transform infrared spectroscopy; Qualitative identification of amines
1. Introduction During the past few years the public has become increasingly aware of environmental topics. Especially in the case of objects of daily life, such as yarn, attention is paid more and more to their environmental compatibility. Publications in the press have brought forward presumptions that yarn can cause danger to people’s health. These can be residues of combing, spinning or sizing agents, but above all dyestuffs, formaldehyde, chloroorganic compounds, mothproofing and antimicrobal agents. It is claimed that textile chemicals not only act as allergens but also exhibit toxic and even mutagenic or carcinogenic properties [1]. The sources of the mutagenic activity were the * Tel.: 1 48 33 822 9224; fax: 1 48 33 812 3502. E-mail address: [email protected] (A. Pielesz)
dyestuffs applied [2,3]. It is obvious that the dyestuffs themselves provide only a minor part of the mutagenic potential. In textile dyeing usually 80% of the dyestuffs are azo dyes. Some of these dyes may cleave-off under reducing conditions emitting aromatic amines which proved carcinogenic in animal experiments. The process of the reduction of azo dyes with the cleavage of aromatic R–NH2 amines is one of the ways of the degradation of those dyes. The others (Fig. 1) are: photodegradation and biodegradation by means of hydroxylation, oxidation, hydrolysis. However, in human organisms, it is the biological reduction of the azo dye that is responsible for the possible presence of the toxic amine in the organisms. Aromatic amines are specified [4,5] in the groups III A1 or III A2 of the Maximale Arbeintsplatz Konzentration (MAK) list as well as in IARC (International Agency for Research on Cancer) and ETAD (Ecological and Toxicological Association of the
0022-2860/99/$ - see front matter q 1999 Elsevier Science B.V. All rights reserved. PII: S0022-286 0(99)00176-3
338
A. Pielesz / Journal of Molecular Structure 511–512 (1999) 337–344
Fig. 1. Schematic model of the degradation of azo dyes [1].
Dyestuffs Manufacturing) lists (Table 1). The capability to form any of the above listed carcinogenic amines through cleavage of one or more azo groups is the reason why they all fall under the category of Table 1 The list of MAK amines MAK amines MAK III A1
MAK III A2
Nr CAS Benzidine 4-Aminodiphenyl 4-Chloro-o-toluidine 2-Naphtyloamine o-Aminoazotoluene 2-Amino-4-nitrotoluene p-Chloroaniline 2,4-Diaminoanisole 4,4 0 -Diaminodiphenylomethane 3,3 0 -Dichlorobenzidine 3,3 0 -Dimethoxybenzidine (odianisidine) 3,3 0 -Dimethylobenzidine (otolidine) 3,3 0 -Dimethyl-4,4 0 diaminodiphenylmethane p-crezidine 4,4 0 -Methyleno-bis-(2chloroaniline) 4,4 0 -Oxydianiline 4,4 0 -Tiodianiline 2-methylaniline (o-toluidine) 2,4-Toluylendiamine 2,4,5-Trimethylaniline
92-87-5 92-67-1 95-69-2 91-59-8 97-56-3 99-55-8 106-47-8 615-05-4 101-77-9 91-94-1 119-90-4 119-93-7 838-88-0 120-71-8 101-14-4 101-80-4 139-65-1 95-53-4 95-80-7 137-17-7
banned azo dyes. The import and marketing of corresponding textile and leather goods in Germany are likewise forbidden (the ban introduced in April 1996) [6]. The stringent regulation has made German buyers very sceptical of purchasing goods from their Asian business counterparts. I would like to add that in India, although the ban on benzidine was introduced two years ago, the use and manufacture of benzidine continued until recently due to its low cost [7]. The banned amines must be formed on reduction of the azo groups and not by other decomposition reactions under stronger conditions of analysis. The modification of the ordinance is based on the fact that it should cover only those bioavailable azo dyes which are likely to be split by enzymes in organisms. During exchange, the reductases in liver or intestinal bacteria can split only azo groups and not other bonds [8,9]. The association of consumers for eco-friendly yarn, published the method and it is obligatory with TLC, HPLC, or GC/MS techniques [4,10,11]. In the present study MAK amines were analysed by FT-IR spectroscopy.
2. Experimental Two methods of chemical reduction were adopted. More drastic conditions of the reduction process [12] involved: 1 g of yarn or 0.06 g of dye (i.e. the quantity fitting to standard of 3% dyeing). The sample was
A. Pielesz / Journal of Molecular Structure 511–512 (1999) 337–344
339
Fig. 2. The azo dye Direct Black 38 and the product of the reduction of Direct Black 38 benzidine.
heated in boiling temperature with 1 M NaOH for 1 h, after 30 min 0.6 g sodium dithionite was added (p.a. Sigma–Aldrich). Under less drastic conditions of reduction [13], the reduction was carried out at 708C at pH 6 using a citrate buffer with 0.6 g sodium dithionite per gram of fibre. The extract was transferred to Extrelut 20 columns into dichloromethane absolute (Merck). According to Ref. [12] methanol or acetic acid methyl ester was used for extraction. Identification of amines in artificial sweat was performed basing on the standard: PN-91/P-04913 (eqv ISO 105-E04/96). The FT-IR spectra of the pure components, samples were recorded on a Magna 860 Nicolet spectrometer. The following conditions were used: spectral resolution 4 cm 21, number of scans 50, collimator of beams.
3. Results and discussion It is known that every compound can be described by its characteristic IR spectrum. This kind of analysis has been carried out [14] before by means of a
comparison of aromatic amines standard. In the current study carcinogenic MAK amines were sought in the samples of azo dyes and yarn which had previously been subjected to a process of chemical reduction with sodium dithionite. The analysed samples of yarn were those dyed with benzidine dyes Figs. 2 and 3). Direct Black 38 and Direct Brown 95 dyes are typical direct dyes used in dyeing textiles and cotton yarn. Yarn dyed with the above dyes was subjected to a chemical reduction [13] in order to observe the process of reconstruction of the MAK amine, which in this case was benzidine, after the reduction of the dye. Fig. 4 presents a comparative analysis of the standard of MAK amine benzidine and benzidine, the product of the reduction of yarn dyed with Direct Black 38 and Direct Brown 95. A good comparative range is the spectral range of 2000–600 cm 21. After the chemical reduction of the dyestuffs, the following bands were reconstructed well: vibrations of the N–H deformating bands for R–NH2 amines (1650– 1590 cm 21), doublet of CyC skeletal vibrations of the aromatic ring (1450–1510 cm 21), C–N stretching vibrations (1180–1360 cm 21) and N–H deformating
Fig. 3. The azo dye Direct Brown 95 and the product of the reduction of Direct Brown 95-benzidine.
340
A. Pielesz / Journal of Molecular Structure 511–512 (1999) 337–344
Fig. 4. Comparison of the spectra of standard benzidine with the samples: (a) benzidine; (b) benzidine-the product of the reduction of yarn dyed with Direct Black 38; (c) benzidine-the product of the reduction of yarn dyed with Direct Brown 95.
vibrations (793–840 cm 21). However, in the range of 3700–2000 cm 21, an outline of vibrations can be detected, those which are attributed to the range of N–H stretching bands for R–NH2 amines (t 3400 cm 21).
A comparison of the reproducibility of MAK amine o-tolidine was carried out, later depending on the chemical reduction method. The Direct Orange G dye was applied. It is used in dyeing cotton and during reduction it reconstructs o-tolidine (Fig. 5). In the full
A. Pielesz / Journal of Molecular Structure 511–512 (1999) 337–344
341
Fig. 5. The azo dye-Direct Orange G and the product of the reduction of Direct Orange G-o-tolidine.
analytic range (Fig. 6) (3700–600 cm 21) good reproducibility of o-tolidine after reduction can be reported, regardless of whether the process was carried out in less or more drastic conditions of chemical reduction (708C, buffer, pH 6; and boiling temperature, 1 M NaOH, respectively). The fact that the chemical process is carried out in 1 M NaOH allows a complete reconstruction of that sought for the MAK amine. There is a risk, however, that the reconstructed amine is not formed as a result of the reduction of azo groups, but of some other undesirable re-grouping. In order to approximate the process of the chemical reduction to the process of enzyme reduction which takes place in human organisms, and to prevent untrue positive results (which means the presence of amines), the norms which are currently obligatorily recommended that this process should be carried out in less drastic chemical conditions [13]. In the samples (Fig. 6) the range of the vibrations of N–H stretching bands for aromatic amines (3500–3300 cm 21) is clearly discernible. The precise visibility of this range allows the application of the extracting column Extrelut 20. This observation is particularly significant because of the analytic conditions recommended by German standards. Chemical reduction carried out at a temperature of 708C, with the specified pH conditions for the environment, aims at approximating the chemical process to the conditions which are to take place in vivo. Another resemblance to actual conditions, i.e. the contact of dyed textile with human skin, is treating the dyestuff with artificial sweat (Fig. 7). Artificial sweat containing: l-histidine monohydrochloride monohydrate, NaCl, Na2HPO4 or NaH2PO4 where by the means of NaOH its pH was made to equal
pH 8 or pH 5.5, is a commonly accepted norm in the textile industry used in identifying the durability of the dye. The obtained spectra (Fig. 7), which are the result of the reaction of azo dye with artificial sweat, do not give a satisfactory answer to the problem of the reconstruction of the sought for carcinogenic MAK amine. Application of the TLC method produces similar results. [15] What proves it is mainly the lack of the bands t 3400 cm 21 which are characteristic to R– NH2 amine. The range of 2000–600 cm 21 does not correspond with the bands characteristic to o-tolidine either. In this way, the problem of the penetration of carcinogenic MAK amines into the insides of human organisms through the skin (through contact with sweat) still remains open. However, it is known that people involved in making benzidine dyes and in danger of contact with increased concentration of benzidine suffered from cancer of the bladder [16,17]. However, until now, it has not been fully proved that wearing clothing dyed with azo dyes cleaving under reduction of amine, leads to such a type of cancer. It follows from this work that the process of the reduction of dye in buffer (pH 6) cannot be satisfactorily compared with the reaction of dye with artificial sweat (pH 5.5 or 8). The presented results of research with the use of FT-IR spectroscopy to identify MAK amines are of pilot character and will be extended in consecutive papers mainly by the quantitative analysis of MAK amines.
4. Conclusions Figs. 4, 6 and 7 illustrate a number of spectroscopic analyses of MAK amines. Similar dependencies can
342
A. Pielesz / Journal of Molecular Structure 511–512 (1999) 337–344
Fig. 6. Comparison of the spectra of standard o-tolidine with the samples: (a) o-tolidine; (b) o-tolidine-the product of the reduction of dye Direct Orange G in NaOH; (c) o-tolidine-the product of the reduction of dye Direct Orange G in citrate buffer.
be observed in other amines and azo dyes, which are capable of a reductive split of MAK amines. The presented results of the research work using FT-IR spectroscopy can constitute a competitive method of analysis to the currently recommended chromatographic methods (especially TLC).
Acknowledgements The author wishes to thank M.S.W. Binis´ for technical assistance in the analyses of MAK amines. This work was supported by KBN Poland, Grant no 7 TO8E 033 14.
A. Pielesz / Journal of Molecular Structure 511–512 (1999) 337–344
343
Fig. 7. Comparison of the spectra of o-tolidine standard with the samples: (a) o-tolidine; (b) D. Orange treated with acid sweat; (c) D. Orange treated with alkaline sweat.
References [1] R. Anliker, JSDC 9 (1979) 317. [2] G. Pfizenmaier, Natur 9 (1990) 71. [3] G. Pfizenmaier, T. Pflaum, Natur 3 (1995) 40.
[4] Zweite Verordung zur Anderung, Bundesgesetzblatt, Jahrgang 15 (7) (1994) Teil I. [5] Vierte Verordrung zur Anderung der Bedarfsgegenstandenverordnung, Bundesgesetzblatt, Jahrgang 20 (7) (1995) Teil I.
344
A. Pielesz / Journal of Molecular Structure 511–512 (1999) 337–344
[6] Dritte Verordung zur Anderung der Bedarfsgegenstandenverordnung vom16 Dezember 1994, Bundesgesetzblatt, Jahrgang (1994) Teil I.N.R.F. [7] Technical Support Staff (AG), Colourage 9 (1996) 19. [8] K.T. Chung, Mutation Research 114 (1983) 269. [9] S.W. Collier, J.E. Storm, R.L. Bronaugh, Toxicology and Applied Pharmacology 118 (1993) 73. [10] E. Idaka, T. Ogawa, JSDC 3 (1978) 91. [11] B. Ku¨ster, U. Wahl, Textilveredlung 32 (5/6) (1997) 121. [12] A. Wilken, B.M. Mu¨ller, J. Pieler, H. Ho¨cker, The Ninth
[13] [14]
[15] [16] [17]
International Textile Research Conference, Biella, Italy, 1995, p. 263. W.B. Achwal, Colourage 5 (1997) 29. A. Pielesz, W. Binias´, A. Włochowicz, The Second International Conference, Ło´dz´-Arturo´wek, Poland, 23–24 June 1998, p. 12. A. Pielesz, S. S´wierczek, A. Włochowicz, I. Baranowska, J. Planar. Chromatogr. 12 (1999) 215. G.M. Matanoski, E.A. Elliot, Epidemiol. Rev. 3 (1981) 203. J.A. Indulski, W. Lutz, Pol. J. Occup. Med. 5 (2) (1992) 143.