Acta Chim. Slov. 2005, 52, 111–118 111 Scientific Paper Presence of Dioxins in Textile Dyes and Their Fate During the Dyeing Processes Boštjan Križanec,a* Alenka Majcen Le Marechal,a Ernest Vončina,b and Darinka Brodnjak-Vončinac " Faculty of Mechanical Engineering, University of Maribor, Smetanova 17, SI-2000 Maribor, Slovenia b Environmental Protection Institute, Prvomajska ul. 1, SI-2000 Maribor, Slovenia c Faculty of Chemistry and Chemical Engineering, University of Maribor, Smetanova 17, SI-2000 Maribor, Slovenia Received 06-01-2005 Abstract Considerable levels of highly tojric polychlorinated dibenzo-/?-dioxins (PCCDs) and polychlorinated dibenzofurans (PCDFs) were determined in two among the six analysed disperse textile dyes. The dioxin homologue profile of these dyes was similar to that found in some environmental and industrial samples, connected with the textile industry. Dyes contaminated with dioxins were further used in industrial polyester dyeing processes at labora-tory scale. We observed the changes in dioxin contents, dioxin transformations and their distribution during the textile dyeing process. After the dyeing and textile finishing processes the content of dioxins was up to fifteen times higher. More than 85% of the total dioxin content was found in dyed polyester. Other 15% was discharged with waste dye bath. Our results confirmed that the presence of dioxins in some textile dyes may be a significant source regarding human exposure and environmental contamination. Key words: polychlorinated dibenzo-/?-dioxins, polychlorinated dibenzofurans, textile dyes, formation Introduction Dioxin is a term for a group of poly-halogenated aromatic hydrocarbons including 75 polychlorinated dibenzo-/?-dioxins (PCDDs) and 135 polychlorinated dibenzofurans (PCDFs).1 Dioxins are persistent, toxic pollutants that accumulate in animal and human fats.2 Exposure to even low doses of dioxins can lead to cancer, damage of the nervous system, immune system diseases and reproductive disorders.3 Their structures are very similar, differing only in the number and spatial arrange-ment of chlorine atoms in the molecules (Figure 1). 8r< Clx----T i r 11-------------u i ~~hrClv Clx r —rrClv 6 u 4 a. PCDDs (X,Y=1-4) 6 U 4 b. PCDFs(X,Y=1-4) Figure 1. Molecular structure of the polychlorinated dibenzo-p-dioxins (a) and polychlorinated dibenzofurans (b). Isomers with chlorine atoms at positions 2,3,7,8 are especialh/ toxic and persistent. The so-called “dirty group” presents 17 isomers of PCDD/Fs. In the environment, PCDD/Fs can be transported over great distances through evaporation and condensa-tion cycles.4 As a result of global circulation patterns and low evaporation rates in cold climates, dioxins tend to accumulate in arctic regions where they bio-accumulate in living organisms.5 PCDD/Fs, therefore, present a global environmental and health problems. Thermal processes are the main source of dioxins. Dioxins are formed in the gas phase at temperatures above 600 °C and on the surface of solid phase in the temperature range betvveen 225-400 °C.6 Chemical industry is an important source of (PCDD/Fs) as by products.7 PCDD/Fs can be formed during the synthesis of chlorophenols, chlorobenzenes, chlorobiphenyls, polyvinyl chloride, dyes, pigments, printing inks and halogenated pesticides. PCDD/Fs were detected in sewage sludge tested in Germany.8 Following a study of the potential sources of PCCD/Fs in sewage sludge, it was concluded that the contribution of several textile products could account for the source of PCDD/Fs in many municipal waste water treatment plants.9 Furthermore, a logical category of products were tested to determine the sources of di-oxins. The concentrations of PCDD/Fs were determined in different new garments, ranging from low pg/g to high 300 ng/g. The octachloro dibenzo-/?-dioxin (OCDD) was the dominant homologue.10 Dioxin homologue patterns that were found in more contaminated textile samples were annotated to PCDD/Fs patterns connected to pentachlorophenol and chloranil based dyes. y y O Križanec et al. Presence of Diozins in Teztile Dyes 112 Acta Chim. Slov. 2005, 52, 111-118 The contamination of textile fibres during produc-tion and finishing was also investigated.11 Cotton cloth was subjected to a series of 16 typical finishing processes and analysed for PCDD/Fs at various stages of treat-ment. The maximum concentrations found in the raw textile products were 30 ng/kg in cotton and 45 ng/kg in synthetic materials. Concentration increases during treatment processes were attributed to an increase in OCDD. The contribution of textile production and finishing to the PCDD/Fs concentration increased with dyeing, and with wash and wear finishing processes resulted in a maximum concentration of 100 ng/kg. In this study only a few textile processes were investigated covering a small range of chemicals used in the textile industry. In addition, the concentrations of PCDD/Fs in the waste waters and the used chemicals were not determined. A relativeh/ small amount of data is available for PCDD/Fs contents in textile dyes and pigments. Considerable levels of PCDD/Fs were determined in some dioxazine dyes and pigments, phtalocyanine dyes and in printing inks. Dioxazine pigments were derived from chloranil, which was found to contain high levels of PCDD/Fs and has been suggested as the source of contamination.12 In a sample of Ni-phthalocyanine dye higher congeners of PCDD/Fs were found in/xg/kg concentration level.13 Considerable levels of PCDD/Fs were also determined in some printing inks obtained from a supplier in Germany.14 The identities of the dyes and pigments in these inks were not reported. Synthesis of colorants represents a relativeh/ large group of chemicals with complex synthesis processes. During synthesis of some colorants polychlorinated dibenzo-/?-dioxins and polychlorinated dibenzofurans (PCDD/Fs) can be formed.12"14 Further formations of PCDD/Fs can occur via dyeing and textile finishing processes with conditions favourable for the generation of PCDD/Fs (high temperatures, alkaline conditions, UV radiations or other radical starters). The main object of this work was to determine the presence and fate of dioxins, as well as the precursors' compounds, in some selected textile dyes used by lo-cal industries. Emphasis was devoted on two black disperse dyes in which high levels of PCDD/Fs were determined. Experimental Textile disperse dyes were supplied by two dif-ferent producers. The two black disperse dyes were a mixtures of anthraquinone disperse and azo-disperse dyes (Dye 1, Dye 2). The complete chemical composi-tion of these dyes is unavailable. Commercial polyprene (polyester) fibres were used for the dyeing experiments. Ali the chemicals used were of analytical grade or dioxin analytical grade. Standards of PCDD/Fs were purchased from the Cambridge Isotope Laboratories (CIL, USA). The analytical procedure for the determination of PCDD/Fs is quite complicated because concentrations of dioxins are low when compared to other chlorinated aromatic compounds like polychlorinated biphenyl ethers and polychlorinated biphenyls present in samples. High efficiency in the cleanup methods is necessary to make the analysis possible. Organic solvent extraction is used together with cleanup of the extract by multi-step column chromatography. The quantifica-tion of dioxins is based on an isotope dilution procedure using isotopically labelled 13C12-PCDD/Fs. Dye samples (1 g) were spiked with an internal standard mixture containing 13C12-labelled isomers (100 pg) in 100/xL of nonane. The samples were then diluted in ethanol-water mixture and extracted with hexane. The solubility of ali dyes was good in ethanol:water (1:1) mixture with an insignificant presence of emulsion by liquid-liquid extraction with hexane. Cleanup of organic (hexane) extract was performed on a mixed column (layers: silica gel/sulphuric acid, silica gel/KOH and silica gel) followed by additional cleaning using adsorp-tion chromatography on a graphitised carbon column. Using adsorption chromatography on a graphitised carbon column, we separated the dioxin compounds that are planar, from other nonplanar interferences. The obtained dioxin fraction in toluene (60 mL) was concentrated to a final volume of 20 /xL and analysed for PCDD/Fs content. Two dyeing experiments were performed separaten with 9 g of polyprene fibres. Disperse dyes (Dye 1 and Dye 2), which contain PCDD/Fs, were used in an industrial polyprene fibres dyeing process. Dyeing was carried out in a laboratory scaled dyeing machine MATHIS LABOMAT BFA-8 (Warner Mathis AG, Switzerland) equipped with infrared heating, in stainless steel dyepots of 200 cm3 capacities. The dye-bath was maintained at 130 °C for 45 min. After dyeing, sample reduction clearing was carried out by heating in an aque-ous solution containing sodium dithionite (Na2S204) and sodium hydroxide at 70 °C. After the treatment, the samples were rinsed with distilled water and dried in the open air. Concentration of PCDD/Fs was determined in coloured polyprene fibres and in the waste dye-bath. A recovery test was performed by adding 37Cl35-labelled 2,3,7,8-TCDD to the dye bath containing the fibres before the dyeing experiment. The complete process of dyeing and finishing is shown in Figure 2. The final determination of PCDD/Fs in the sample extract was carried out using high resolution gas chromatographic separation on a HP 6890 GC (Hewlett-Packard, Palo Alto, CA, USA) coupled to a Finnigan MAT 95PL (Finnigan, Bremen, Germany) high resolution mass spectrometer. An aliquot (2 /xL) Križanec et al. Presence of Diozins in Textile Dyes Acta Chim. Slov. 2005, 52, 111-118 113 130°C, 45 min Start: Dye-bath 50°C, 20 min pH = 9-9.5 Temp. rate: 2°/min 45°C Waste dye-bath: Smp 2 Fabric-polyprene (9 g), Disperse dye (0.3 g), Distilled water (180 mL), SOLPON G-392 (0.18 g); Fatty alcohol efhoxylates, TC-PUFER FPA (0.54); Mixture of alkyl betaines, amino carboxylates and inorganic reducing agents, ALVIRON EFP (0.27 g); Mixture of fatty acid ethoxyilates and alkyl aryl sulfonates. Reduction clearing Colored polypren,Distilled water (180 mL), > 40% aq. NaOH (0.5 mL), ¦ Sodium dithionat Na2S204 (0.36g) V Colored polypren: Smp 1 V Room temperature 70° C, 20 min 45°C Wash with distilled water Figure 2. Dyeing method. of sample was injected into the GC system, equipped with a JW-DB-5MS+DG capillary column (60m x 0.25 mm i.d., film thickness 0.25/xm) in splitless mode. The mass spectrometer operates in the electron impact ionization mode using selected ion monitoring (SIM), at a minimum resolution of 10,000. Samples were ana-lyzed for the PCDD/Fs concentrations using the isotope dilution method based on US EPA 1613 protocol.15 In addition to daily sensitivity and relative response factor (RRF) checks, the mean RRF was regularly re-evaluated for each congener. Quality control samples were included in the analysis scheme to ensure control of the analysis. Toxic equivalents (TEQs) were calcu-lated using WHO toxic equivalency factors (TEFs).16 Results and discussion Ali determinations of PCDD/F contents in the dye samples and the dyeing experiment samples were made in duplicate and the results given are the mean values of the two measurements. Among the six analysed samples of textile dyes, only in two disperse black dyes (Dye 1, Dye 2) was a considerable level of PCDD/Fs found (Table 1). OCDD was the dominant compound. The PCDD/Fs homologue profile of the above mentioned dyes (Figure 3) is similar to that already found in laundry wastewater, domestic wastewater, sewage sludge, dry cleaning residues and some textile samples.8"12 This profile was annotated to PCDD/Fs patterns connected to pentachlorophenol, suggesting that this could be the source of the PCDD/Fs in these samples. The homologue profile of Dye 1 and Dye 2 differ from homologue profiles found in chloranil-based dyes12 and Ni-phthalocyanine dyes13 but agree well with the profile found in some printing inks.14 16000 : 14000 : 12000 - 10000 - 8000 - 6000 4000 2000 0 ¦ Dye 1 DDye2 Figure 3. The PCDD/Fs homologue profile of Dye 1 and Dye 2. The distribution of dioxins and their fate during textile dyeing processes were further investigated. A simple mass balance of PCDD/Fs in dyeing processes was performed, conducted using disperse dyes, Dye 1 and Dye 2. Several precautionary steps were taken to ensure the absence of PCDD/Fs contamination from other sources, as dyes. Prior to the dyeing experiments, ali laboratory glassware was rinsed with a toluene-acetone mixture. Concentrations of PCDD/Fs were determined Križanec et al. Presence of Diozins in Teztile Dyes 114 Acta Chim. Slov. 2005, 52, 111-118 Table 1. Concentrations of PCDD/Fs and TEQ in disperse dyes (pg/g). Concentration (pg/g) Table 2. Mass balance of PCDD/Fs for the dyeing process with Dye 1. Congener/Group Dye 1 Dye 2 Dye 3 Dye 4 Dye 5 Dye 6 2,3,7,8-TCDD TCDD (tetra dioxins) 1,2,3,7,8-PCDD PCDD (penta dioxins) 1,2,3,4,7,8-H6CDD 1,2,3,6,7,8-H6CDD 1,2,3,7,8,9-H6CDD H6CDD (hexa dioxins) 1,2,3,4,6,7,8-H7CDD H7CDD (hepta dioxins) 1,2,3,4,6,7,8,9-OCDD 2,3,7,8-TCDF TCDF (tetra furans) 1,2,3,7,8-PCDF 2,3,4,7,8-PCDF PCDF (penta furans) 1,2,3,4,7,8-H6CDF 1,2,3,6,7,8-H6CDF 2,3,4,6,7,8-H6CDF 1,2,3,7,8,9-H6CDF H6CDF (hexa furans) 1,2,3,4,6,7„-H7CDF 1,2,3,4,7,8,9-H7CDF H7CDF (hepta furans) 1,2,3,4,6,7,8,9-OCDF a a a a a a a 10 35 24 29 219 8 135 824 2405 1131 4408 1954 6396 5928 15826 <• 49 700 301 45 96 12 37 426 954 109 215 18 74 85 68 30 129 759 1096 100 421 57 445 181 1014 80 127 " 27 75 128 331 38 12 26 a a 38 9 a a a a 6 a a " " 93 ° a 15 a a 27 98 16 10 26 25 " Sum PCDD/Fs 10862 28143 524 53 220 9 Sum TEQ-WHO 50 170 <5 <5 10 <5 Sum 2,3,7,8 PCDD/Fs 7638 22279 406 53 182 9 " ND (<5) - not determined (<5). in the raw polyprene fibres, and in the reagents. A blank experiment was performed without the addition of dye. The concentrations of PCDD/Fs in the blank samples were close to the detection limit. The input for mass balance, therefore, presents a content of PCDD/Fs in 0.3 g of dye. For the output, the content of PCDD/Fs was determined in coloured polyprene samples and waste dye-bath samples. The content of PCDD/Fs in the reduction clearing baths was under the detection limit. The mass balance of PCDD/Fs for the dyeing process with Dye 1 is shown in Table 2 and the mass balance of PCDD/Fs for the dyeing process with Dye 2 is shown in Table 3. After the textile finishing processes with disperse dyes (Dye 1, Dye 2) the content of the PCDD/Fs was approximately tenfold higher. There is strong evidence that PCDD/Fs are formed from precursors' com-pounds present in these dyes during the textile finishing Congener/Group hiput-Dye 1 Smp 1 Smp 2 Outlet-Sum'3 (pg-abs) (pg-abs) (pg-abs) (pg-abs) TCDD PCDD H6CDD H7CDD OCDD TCDF PCDF H6CDF H7CDF OCDF b b 247 586 1778 210 128 228 54 24 192 2497 7765 23812 320 343 329 57 34 24 345 869 2938 24 57 25 10 6 216 2842 8634 26750 343 400 354 67 34 2,3,7,8-TCDD 1,2,3,7,8-PCDD 1,2,3,4,7,8-H6CDD 1,2,3,6,7,8-H6CDD 1,2,3,7,8,9-H6CDD 1,2,3,4,6,7,8-H7CDD 1,2,3,4,6,7,8,9-0 CDD 2,3,7,8-TCDF 1,2,3,7,8-PCDF 2,3,4,7,8-PCDF 1,2,3,4,7,8-H6CDF 1,2,3,6,7,8-H6CDF 2,3,4,6,7,8-H6CDF 1,2,3,7,8,9-H6CDF 1,2,3,4,6,7,8-H7CDF 1,2,3,4,7,8,9-H7CDF 1,2,3,4,6,7,8,9-OCDF b b 10 6 339 1778 6 13 b 33 5 25 9 30 17 24 65 89 61 2971 23812 12 11 9 347 2938 b b 17 8 58 o b 29 21 38 21 34 6 b 11 100 70 3318 26750 6 17 8 58 b 29 21 38 21 34 Sum PCDD/Fs 3255 35349 4292 39641 Sum TEQ-WHO 13 64 9 73 Sum 2,3,7,8 PCDD/Fs 2283 27224 3317 30541 " Sum of absolute amounts of PCDD/Fs in coloured polyprene (Smp 1) and in waste dye-bath (Smp 2). b ND (<5) - not determined (<5). processes. The PCDD/Fs homologue profile suggests that in this čase chlorinated phenols are most probabh/ precursors' compounds. More than 85% of the total dioxin content was found in the dyed polyester samples. Other 15% was discharged with waste dye bath. The aim of further experiments was to determine the point of PCDD/Fs formation in the dyeing experi-ment, and the influences of dyeing temperature and pH conditions on the formation of PCDD/Fs. The results in Table 4 present the mass balance for dyeing process with Dye 2 at 150 °C for 45 min. Other experimental conditions are the same as in previous experiments. The results of this experiment are compara-ble with those results obtained with the described b b h b b b b b b b Križanec et al. Presence of Diozins in Teztile Dyes Acta Chim. Slov. 2005, 52, 111-118 115 Table 3. Mass balance of PCDD/Fs for the dyeing process with Dye 2. Table 4. Mass balance of PCDD/Fs for the dyeing process with Dye 2 at higher temperature (150 °C). Congener/Group Input-Dye 2 (pg-abs) Smp 1 Smp 2 (pg-abs) (pg-abs) Outlet-Sum" (pg-abs) Congener/Group Input-Dye 2 (pg-abs) Smp 1 Smp 2 (pg-abs) (pg-abs) Outlet-Sum" (pg-abs) TCDD b b 6 b TCDD b 13 b 13 PCDD 7 110 b 110 PCDD 7 123 b 123 H6CDD 722 4119 125 4244 H6CDD 722 3390 58 3448 H7CDD 1919 7553 174 7727 H7CDD 1919 5868 30 5898 OCDD 4748 28250 435 28685 OCDD 4748 21572 279 21851 TCDF 90 116 b 116 TCDF 90 162 b 162 PCDF 286 284 b 284 PCDF 286 233 b 233 H6CDF 329 290 10 300 H6CDF 329 232 b 232 H7CDF 304 259 6 265 H7CDF 304 225 5 230 OCDF 38 30 b 30 OCDF 38 24 b 24 2,3,7,8-TCDD " " " " 2,3,7,8-TCDD " " " " 1,2,3,7,8-PCDD b b b b 1,2,3,7,8-PCDD b b f b 1,2,3,4,7,8-H6CDD 9 61 b 61 1,2,3,4,7,8-H6CDD 9 14 b 14 1,2,3,6,7,8-H6CDD 66 58 b 58 1,2,3,6,7,8-H6CDD 66 57 " 57 1,2,3,7,8,9-H6CDD 40 29 b 29 1,2,3,7,8,9-H6CDD 40 34 b 34 1,2,3,4,6,7,8-H7CDD 1322 3154 70 3224 1,2,3,4,6,7,8-H7CDD 1322 2567 30 2597 1,2,3,4,6,7,8,9-OCDD 4748 28250 435 28685 1,2,3,4,6,7,8,9-OCDD 4748 21572 279 21851 2,3,7,8-TCDF 15 12 ND 12 2,3,7,8-TCDF 15 11 b 11 1,2,3,7,8-PCDF 29 23 b 23 1,2,3,7,8-PCDF 29 15 b 15 2,3,4,7,8-PCDF 11 10 ND 10 2,3,4,7,8-PCDF 11 6 b 6 1,2,3,4,7,8-H6CDF 65 73 b 73 1,2,3,4,7,8-H6CDF 65 70 " 70 1,2,3,6,7,8-H6CDF 22 25 " 25 1,2,3,6,7,8-H6CDF 22 17 b 17 2,3,4,6,7,8-H6CDF 21 17 b 17 2,3,4,6,7,8-H6CDF 21 14 b 14 1,2,3,7,8,9-H6CDF 39 28 b 28 1,2,3,7,8,9-H6CDF 39 27 b 27 1,2,3,4,6,7,8-H7CDF 126 77 6 83 1,2,3,4,6,7,8-H7CDF 126 63 5 68 1,2,3,4,7,8,9-H7CDF 133 145 b 145 1,2,3,4,7,8,9-H7CDF 133 133 6 133 1,2,3,4,6,7,8,9-OCDF 38 30 b 30 1,2,3,4,6,7,8,9-OCDF 38 25 b 25 Sum PCDD/Fs 8443 41011 750 41761 Sum PCDD/Fs 8443 31842 372 32214 Sum TEQ-WHO 51 73 1 74 Sum TEQ-WHO 51 58 1 59 Sum 2,3,7,8 PCDD/Fs 6684 31992 511 32503 Sum 2,3,7,8 PCDD/Fs 6684 24625 314 24939 " Sum of absolute amounts of PCDD/Fs in coloured polyprene (Smp 1) and in waste dye-bath (Smp 2). b ND (<5) - not de-termined (<5). " Sum of absolute amounts of PCDD/Fs in coloured polyprene (Smp 1) and in waste dye-bath (Smp 2). b ND (<5) - not de-termined (<5). dyeing conditions (Table 2). These results suggest that temperature has no significant influence on the formation of PCDD/Fs during the dyeing process. Finally, the dyeing experiment was performed with Dye 1 as described in Figure 2, but without the reduc-tion clearing finishing process. The PCDD/Fs content was determined in waste dye bath and in the dyed polyprene sample prior to reduction clearing (Table 5). The results of the performed experiments suggest that formation of PCDD/Fs mainly occurs during dye-ing (not reduction clearing), and that higher temperature (150 °C) has no significant influence on PCDD/F formation. We also investigated the influence of pH-condi-tions on PCDD/Fs formation during analysis of the dye samples. PCDD/Fs are, according to literature, very sta-ble under acid conditions. Acid wash sample treatment is often used for analytical sample treatment, especially for the cleanup of biological samples.17"19 On the other hand, it was confirmed that dechlorination of PCDD/Fs occurs in the high alkaline solutions.20 For this purpose three samples of Dye 1 analyses were separately treated under different pH-conditions (Table 6). The cleanup of organic (hexane) extract was the same for ali samples as previous described. The results are shown in Table 7. Križanec et al. Presence of Diozins in Teztile Dyes 116 Acta Chim. Slov. 2005, 52, 111-118 Table 5. Mass balanc Dye 1 without reduc e of PCDD/Fs for the dyeing process with tion clearing. Input-Dye 1 Smp 1 Smp 2 Outlet-Sum" (pg-abs) (pg-abs) (pg-abs) (pg-abs) 15 15 Table 7. Determined concentrations of PCDD/Fs in Dye 1 using different approaches in sample preparation. Congener/Group Congener/Group Dye 1 (pg/g) Dye 1/KOH (pg/g) Dye I/H2SO4 (pg/g) TCDD TCDD ' 25 24 PCDD b 77 5 82 PCDD 10 14 12 H6CDD 247 1904 93 1997 H6CDD 824 317 354 H7CDD 586 4589 189 4778 H7CDD 1954 403 394 OCDD 1778 19455 579 20034 OCDD 5928 1141 1145 TCDF 210 344 19 363 TCDF 700 637 659 PCDF 128 271 23 294 PCDF 426 319 284 H6CDF 228 204 11 215 H6CDF 759 300 289 H7CDF 54 99 14 113 H7CDF 181 75 79 OCDF 24 37 7 44 OCDF 80 49 47 2,3,7,8-TCDD " " b b 2,3,7,8-TCDD " 25 24 1,2,3,7,8-PCDD b b b b 1,2,3,7,8-PCDD " 13 9 1,2,3,4,7,8-H6CDD b 40 b 40 1,2,3,4,7,8-H6CDD " " " 1,2,3,6,7,8-H6CDD 10 47 b 47 1,2,3,6,7,8-H6CDD 35 19 " 1,2,3,7,8,9-H6CDD b 21 b 21 1,2,3,7,8,9-H6CDD 8 70 69 1,2,3,4,6,7,8-H7CDD 339 1739 70 1809 1,2,3,4,6,7,8-H7CDD 1131 210 210 1,2,3,4,6,7,8,9-OCDD 1778 19455 579 20034 1,2,3,4,6,7,8,9-OCDD 5928 1141 1145 2,3,7,8-TCDF 6 b b b 2,3,7,8-TCDF " 25 27 1,2,3,7,8-PCDF 13 15 b 15 1,2,3,7,8-PCDF 45 34 21 2,3,4,7,8-PCDF b 7 b 7 2,3,4,7,8-PCDF 12 19 15 1,2,3,4,7,8-H6CDF 33 43 b 43 1,2,3,4,7,8-H6CDF 109 41 35 1,2,3,6,7,8-H6CDF 5 b b b 1,2,3,6,7,8-H6CDF 18 16 18 2,3,4,6,7,8-H6CDF 25 29 b 29 2,3,4,6,7,8-H6CDF 85 31 30 1,2,3,7,8,9-H6CDF 9 19 b 19 1,2,3,7,8,9-H6CDF 30 36 36 1,2,3,4,6,7,8-H7CDF 30 46 11 57 1,2,3,4,6,7,8-H7CDF 100 47 53 1,2,3,4,7,8,9-H7CDF 17 24 b 24 1,2,3,4,7,8,9-H7CDF 57 32 25 1,2,3,4,6,7,8,9-OCDF 24 37 1 44 1,2,3,4,6,7,8,9-OCDF 80 49 47 Sum PCDD/Fs 3255 26995 940 27935 Sum PCDD/Fs 10862 3280 3287 Sum TEQ-WHO 13 44 3 47 Sum TEQ-WHO 50 76 66 Sum 2,3,7,8 PCDD/Fs 2283 21522 667 22189 Sum 2,3,7,8 PCDD/Fs 7638 1808 1764 " Sum of absolute amounts of PCDD/Fs in coloured polyprene (Smp 1) and in waste dye-bath (Smp 2). b ND (<5) - not de-termined (<5). ' ND (<5) - not determined (<5). Table 6. Different approaches in sample preparation. Sample: Dyel Dye 1/KOH Dye 1/H2S04 Dissolving EtOH: H20 (150 mL) 2 M KOH/H20 (150 mL) Extraction/time Hexane 50 mL/ 24 h Hexane 50 mL/ 24 h 2 M H2SO4/H2O (150 mL) Hexane 50 mL/ 24 h It is evident from the results that transforma-tion reactions of PCDD/Fs occur during KOH and H2SO4 sample treatment (dechlorination, chlo-rination, molecule splitting…), resulting in higher concentrations of lower, and more toxic, congeners (TCDD) and in the decreasing of higher chlorinated compounds (OCDD). Our results are comparable with those obtained by catalytic transformation proc-esses of PCDD/Fs in the presence of a metal catalyst (Pd,Pt,Zn),21"25 and suggest that sample treatment conditions are very important for the formation/trans-formation of PCDD/Fs and, therefore, for accurate determination of PCDD/Fs in textile dye samples. Križanec et al. Presence of Diozins in Textile Dyes Acta Chim. Slov. 2005, 52, 111–118 117 Conclusions We analyzed six textile dyes for PCDD/Fs. In two disperse black dyes which were a mixture of anthraquinone disperse and azo-disperse dyes, considerable levels of PCDD/Fs were determined. The PCDD/Fs homolouge profile found in these dyes is similar to that found previoush/ in textiles and samples connected with the textile industry. Furthermore, dyes, Dye 1 and Dye 2, contami-nated with dioxins were used in industrial polyester dyeing processes at laboratory scale and the distribution of dioxins and their fate during textile processes was investigated. After the textile finishing processes the content of the PCDD/Fs was approximately tenfold higher. There is strong evidence that PCDD/Fs are formed from precursors' compounds in contaminated dyes under specific conditions during textile finishing processes. Preliminary results, using different approaches for Dye 1 sample analysis, suggest that in the čase of dye-sample preparation for PCDD/Fs analysis, the pH conditions are very important. Textile dyes are complex mixtures with additives which may act like a catalyst for the dechlorination and/or formation of PCDD/Fs under specific conditions. Our future work will further investigate the pres-ence of PCDD/Fs in textile dyes. The distribution of dioxins and their fate during textile processes will be investigated. Emphasis will be devoted to the photo transformation processes of dioxins in textile waste-vvaters and textiles, when coloured with contaminated dyes. The use of ultraviolet light for the degradation and elimination of organic pollutants in contaminated wastewaters is now one of the used processes. Textile wastewaters differentiate in quantities and types of suspended particles, as well as in dissolved organic ma-terials that could either retard or enhance the photolysis of PCDD/Fs. Irradiation of waste waters with powerful (up to 300 kW) UV lamps with H202, NaOCl, Fenton’s regent, etc. as catalysts could be the source of lower chlorinated and more toxic dioxin congeners. The production of dyes and their use is a less investigated source of dioxins. Our results confirm that the presence of dioxins in some dyes may be a significant source regarding human exposure and environmental contamination. Regulation for dioxins in dyes and textiles is obsolete and indistinct in comparison with regulations for other matrices. Regulation for dioxins in substances, preparations and articles (apparel prod-uct) was amended in 1994 with the implementation, in 1996 of Germany jurisdiction.26 This regulation is also valuable for dyes and textiles and is valid world-wide. However, information about the emissions of dioxins from the textile industry is limited, with a lack of com- plete and accurate emission data. The minimisation of environmental and human exposure will be difficult vvithout a full knowledge of dioxins sources. References 1. K. Ballschmiter, R. Bacher. Dioxine; VCH Verlagsgesellschaft mbH: Weinheim-Deutschland, 1996, chapter 2. 2. D. R. Stephens, X. M. Petreas, G. D. Hayward, Sci. Total Environ. 1995, 175, 53-273. 3. P. I. Mitrou, G. Dimitriadis, S. A. Raptis, European Journal of Internal Medicine. 2001, 12, 406-411. 4. A. Palm, I. Cousins, Ö. Gustafsson, J. Axelman, K. Grunder, D. Broman, E. Brorström-Lundén, Environ. Pollut. 2004, 128, 85-97. 5. C. J. Halsall, Environ. Pollut. 2004, 128, 163-175. 6. B. R. Stanmore, Combust. Flame. 2004, 136, 398-427. 7. 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Ukisu, T. Miyadera, Appl. Catal., B. 2003, 40, 141-149. 22. P. Adriaens, P. R. Chang, A. L. Barkovskii, Chemosphere, 1996, 32, 433-441. 23. P. Tundo, A. Perosa, M. Selva, S. S. Zinovyev, Appl. Catal., B. 2001, 32, 1–7. 24. Y. Ukisu, T. Miyadera, Chemosphere. 2002, 46, 507–510. 25. Y. Ukisu, T. Miyadera, Appl. Catal., A. 2004, 271, 165–170. 26. Verordnung uber Verbote und Beschrankungen des Inverkehrbringens gefahrilicher Stoffe, Zubereitung und Erzugnisse nach dem Chemikaliengesetz. http:// bundesrecht.juris.de/bundesrecht/chemverbotsv. Povzetek Dioksine predstavljata skupini toksičnih obstojnih spojin polikloriranih dibenzo-p-dioksinov in polikloriranih dibenzofuranov. V okviru naših raziskav smo preverili prisotnost dioksinov v tekstilnih barvilih. Analizirali smo šest vzorcev tekstilnih barvil. V dveh vzorcih tekstilnih disperznih barvil smo določili znatne vsebnosti dioksinov. Porazdelitev dioksinov v teh vzorcih barvil je podobna porazdelitvi dioksinov določeni v nekaterih vzorcih povezanih s tekstilno industrijo. Barvila, ki vsebujejo dioksine smo uporabili v poizkusih barvanja in spremljali spremembe v porazdelitvi in koncentraciji dioksinov skozi postopek barvanja. Masna bilanca dioksinov v postopku barvanja pokaže povečanje vsebnosti dioksinov, medtem ko ostaja njihova porazdelitev nespremenjena. Pri barvanju pri visokih temperaturah in v alkalnem mediju nastajajo dioksini iz prekurzorskih (predhodnih) spojin. Več kot 85% celotne vsebnosti dioksinov smo določili v vzorcih obarvanega poliestra. Preostalih 15% smo določili v odpadni barvalni kopeli. Rezultati raziskav dokazujejo, da prisotnost dioksinov v nekaterih tekstilnih barvilih predstavlja znaten doprinos k vsebnosti teh spojin v širšem okolju. Križanec et al. Presence of Diozins in Teztile Dyes