No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Determination of banned azo dyes in consumer goods
Abstract
Azo dyes, extensively used for coloring a variety of consumer goods, such as leather, clothes, food, and toys, can under certain conditions be reduced to form confirmed or suspected carcinogenic aromatic amines. This article gives an overview of the state of development of analytical procedures for the determination of such azo dyes, which are banned by the European Commission.
... Furthermore, Azo pigments are desirable in terms of cost and ease of use [3]. Azo pigments make up about 65% of the commercial pigment market [4]. The scientific revolution in the dye industry began in 1859 when researcher William Henry Birkin prepared the first aromatic pigments when he tried to prepare a drug for malaria and observed that the sediment became colored [5]. ...
... ❖ (0.001)M of (J25). ❖ solutions (pH 2-12) [10] 3. 'acid-base characteristics at various pH prepared standard solutions for Azo (J25) at a concentration of 8x10-5 M for different pH values (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12). The solutions' absorbance measured at a range of (320-470) ṇṃ [11]. ...
... used a series of pH value solutionś (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12) to study the acid and base effects of the solutions on the for (J25) [14] and Measure the ionization and protonization constants in the absorption range of 330-470 nm. The pH (2-12) values graphically represent the absorption spectrum of the (8x10-5) M solution of the prepared compounds ( Figure 4). ...
Azo compound was prepared with ethyl-4-aminobenzoate reactor with (2-amino-3(4-hydroxyphenyl) propanoic acid) and this symbol (J25) was suggested. The compound was purified and Recrystallization with absolute ethanol and then performed diagnostic and analytical techniques where the compound was diagnosed with infrared spectrometry and mass spectrometry. Optical spectrometry to pH values within the range (2-12), which included determining the highest absorption value of the compound and identifying Isopstic points. Different polarized solvents also had an impact on electronic spectrometry. The biological effectiveness of the compound (J25) was studied against two types of bacteria (E. coli) and (staphylocococcus Aureuse) and the results showed the positive effect of the compound in inhibiting the growth of bacteria. This study has been legalized and presented for medical, chemical, physical, biological and other applications
... Because of their stability, nitroaromatics are a favorable scaffold for the synthesis of optically active compounds 12,13 . Indeed, derivatives of azobenzene and related compounds form the azo-linked dyes that span the visible electromagnetic spectrum, many of which are common in the cosmetic and pharmaceutical industries and account for 65% of global synthetic food pigments (Supplemental Figure S1a) 3,14 . Despite recent regulation to reduce their prevalence, azo dyes have been linked to a range of disorders including neurotoxicity, genotoxicity, carcinogenicity, and colitis [15][16][17][18] . ...
... Over 84 strains of bacteria have been shown to perform this reaction in cell-based assays with 5-ASA-linked prodrugs 5,6,28,32 . However, few AzoRs derived from commensal gut microbes have been characterized, and the majority of relevant studies have focused on enzymes from Proteobacteria and their processing of azo-linked dyes [7][8][9][10][11]14,18,[33][34][35] . Indeed, only a very small number of AzoRs from Firmicutes and no AzoRs from Bacteroides, the two dominant gut microbial phyla, have been examined to date 8,9,[27][28][29]34,[36][37][38][39] . ...
... Defining the scope of gut microbial AzoRs may facilitate the improved treatment of IBD 3 and/or the management of disorders caused by azo dye metabolism [14][15][16][17][18] . Therefore, we examined AzoRs in the human gut microbiome by employing several datasets, including samples collected longitudinally over one year from patients with IBD and healthy individuals 42 . ...
Prodrugs reliant on microbial activation are widely used but exhibit a range of efficacies that remain poorly understood. The anti-inflammatory compound 5-aminosalicylic acid (5-ASA), which is packaged in a variety of azo-linked prodrugs provided to most Ulcerative Colitis (UC) patients, shows confounding inter-individual variabilities in response. Such prodrugs must be activated by azo-bond reduction to form 5-ASA, a process that has been attributed to both enzymatic and non-enzymatic catalysis. Gut microbial azoreductases (AzoRs) are the first catalysts shown to activate azo-linked drugs and to metabolize toxic azo-chemicals. Here, we chart the scope of the structural and functional diversity of AzoRs in health and in patients with the inflammatory bowel diseases (IBDs) UC and Crohn’s Disease (CD). Using structural metagenomics, we define the landscape of gut microbial AzoRs in 413 healthy donor and 1059 IBD patient fecal samples. Firmicutes encode a significantly higher number of unique AzoRs compared to other phyla. However, structural and biochemical analyses of distinct AzoRs from the human microbiome reveal significant differences between prevalent orthologs in the processing of toxic azo-dyes, and their generally poor activation of IBD prodrugs. Furthermore, while individuals with IBD show higher abundances of AzoR-encoding gut microbial taxa than healthy controls, the overall abundance of AzoR-encoding microbes is markedly low in both disease and health. Together, these results establish that gut microbial AzoRs are functionally diverse but sparse in both health and disease, factors that may contribute to non-optimal processing of azo-linked prodrugs and idiopathic IBD drug responses.
... Azo dyes are classied as monoazo, diazo, triazo, polyazo and azoic [7] based on chemical azo grouping number (AGN). Simultaneously, the largest food-azo-dye group, widely used as per their interesting advantages such as high-water solubility, low production costs, high [8,9] stability, etc. To make it easier to identify dyes throughout the globe, the International Numbering System (INS) was created by Codex Alimentarius (a commission created to protect consumer's health and also to corroborate fair food trade), is mentioned in Table 1. ...
... Various analytical methods are used to analyse azo dyes such as liquid extraction, membrane ltration, solid phase extraction (SPE), thin layer chromatography (TLC), capillary electrophoresis (CE), high performance liquid chromatography (HPLC), liquid chromatography [9][10][11] mass spectrometry (LS-MS) etc. and immunological methods [11]. Beside these, many reports suggest that electrochemical sensors are popular in this eld. ...
... These amines are believed to have potential dangers of causing mutations, genetic damage, and cancer. Although a significant portion of epidemiological research focuses on azo dyes, there is additional evidence suggesting that other types of colorants may provide health risks [8]. The main way that humans are exposed to dyes in cosmetics is via direct contact with the skin. ...
... Since 2002, the European Union has prohibited the use of this dye through legislative restrictions, as a result of a modification to Council Directive 76/769/EEC. [208][209][210][211][212] From an environmental perspective, these dyes are the main causes of concern for textile dyes because they are made up of multiple compounds with distinct functional groups that exhibit notable variations in reactivity, solubility, volatility, stability, and other properties rather than all belonging to the same class of chemical compounds. Due to the variety of chemicals found in dyes, more advanced methods of detection, identification, quantification, and degradation are needed. ...
Providing the reader with an up-to-date digest of the most important current research carried out in the field, this volume is compiled and written by leading experts. This volume reviews the trends in electrochemical sensing and its application and touches on research areas from a diverse range, including electrochemical detection of infectious pathogens, hybrid materials for electrocatalysis and photoelectrocatalysis, chip fabrication from an electrochemical perspective and exploring forensic mysteries with electrochemical sensors, to name just a few.
Coverage is extensive and will appeal to a broad readership from chemists and biochemists to engineers and materials scientists. The reviews of established and current interest in the field make this volume a key reference for researchers in this exciting and developing area.
... studies have shown that synthetic dyes are suspected to release harmful chemicals that are allergic, carcinogenic and detrimental to human health [19]. In contrast, natural dyes are eco-friendly, exhibit better biodegradability and generally have a higher compatibility with the environment than synthetic dyes [20] (A) Solvent extraction: the process is simple, the investment in equipment is low, the technology is easy to learn and understand, and it has the most practical applications. This color extraction method is more efficient than the aqueous method. ...
India has over 450 plants capable of producing dyes. Dyes from natural sources such as plant leaves, roots, bark, insectsecretions and minerals. Natural dyes are mainly used for dyeing natural fibers such as cotton, wool and silk. Most natural colors have special properties such as antibacterial, low toxicity, allergenicity and UV protection. They have been used since ancient times and are widely accepted in various fields such as food, textiles, fine arts and papermaking. There are currently many different dye extraction methods/processes, including Solvent extraction, aqueous extraction, enzymatic extraction, etc. All these extraction methods have their advantages and disadvantages. Experimental results show that it performs well with all natural dyes and may be a better alternative to synthetic dyes. In recent years, it has been observed that synthetic dyes have many drawbacks, such as toxicity, pollution, and allergenicity, but natural dyes do not have such drawbacks. This article discusses the types of natural dye sources and their extraction methods, classification, environmental benefits, and other uses.
... Initroaniline orange), chiefly derived from benzidine, could be cancer causing, toxic and mutagenic to various living species including humans. Due to these reasons, the European Union countries have banned or restricted the use of this category of dyes (Narvekar and Srivastava, 2002;Ahlström et al, 2005). However, in developing countries, most of the dyes are used by industries without toxicity evaluation and these are often released into surface waters or drainage systems (Mathur and Bhatnagar, 2007). ...
Water is one of the essentials that support all forms of plant and animal life and it is generally obtained from two principal natural sources; surface water and groundwater. Groundwater is an important potable, agricultural and industrial source of water. One of the most important environmental issues today is groundwater contamination. Several microorganisms and synthetic chemicals have the potential to pollute groundwater. High chemical concentrations in drinking water can pose a health hazard. Epidemiological studies have shown that the poor quality of drinking water has been responsible for many water-borne diseases. Drinking water containing bacteria and viruses can lead to diseases such as hepatitis or cholera. The main objective of this review paper is to review research on groundwater pollution and contamination as well as pollution types and their effects on public health.
... Food additives, in general, and color, in particular, have been the subject of increased scrutiny in recent years as the safety of their use has been questioned. Only approximately ten dyes are approved for use as food coloring agents in many developed nations today, and many others have been banned in the previous two decades due to their toxicity and carcinogenicity [2,3]. samples and reagents close to the detector. ...
Carmoisine dye, a red azo food colorant commonly utilized to impart a red color to synthetic food products, is the subject of this study. Here, we present a novel reversed flow injection analysis with a chemiluminescence detection (FIA-CL) method employing a newly developed homemade flow cell to determine carmoisine dye. This developed method is based on the inhibition effect of the dye on the chemiluminescence light (CL) emission generated from a luminal-hypochlorite system, whereby the reduction in CL intensity correlates directly with the concentration of carmoisine dye. Investigations into various analytical parameters were conducted to enhance method efficiency and applicability. A linear calibration graph of 4.0 to 100.0 µg mL–1 was established (R² = 0.9993), with a detection limit of LOD = 2.93 µg mL–1. Subsequent application of the proposed method to analyze gelatine dessert samples yielded results in reasonable agreement with those obtained using the reported HPLC method, as evidenced by student t-test and F-test analyses.
... The end products of these dyes are mutagenic and carcinogenic, and DNA damage results when they are ingested and metabolised by marine organisms. 2 With persistent exposure to these dyes, marine sh are affected by genotoxicity, such as increasing erythrocytic micronuclei formation, which induces detrimental effects on the immune system. The azo dyes profoundly impact water bodies by elevating the chemical and biological demand for oxygen. ...
The release of untreated effluents into waterbodies poses a major threat to the environment and human health. The increasing ratio of demands to rate of supply due to the ever-growing population has resulted in the need for large-scale and efficient manufacturing. One of the pitfalls of the fast-paced industrialisation of textiles is the current negligence towards environmental safety and health concerns. Textile dyes, especially azo dyes, are one of the most toxic industrial pollutants. To date, many conventional treatment methods such as aeration lagoons, filtration, sedimentation, flocculation, and coagulation have been used for degradation. Nevertheless, modern techniques such as bioremediation, phytoremediation, and mycoremediation have been proven to be more efficient and feasible due to their eco-friendly nature. Bioremediation is the process of degradation of effluents using microbes. There are two bioremediation strategies: i.e., ex situ and in situ. In situ bioremediation involves the biological degradation of contaminants to benign products onsite. In the ex situ process, pollutants are removed from the contamination site, and then treated. Bioventing, biosparging, bioslurping, land farming, biopiles, and windrows are some techniques that have been in practice. Various microbiological, ecological, and geological factors affect the rate of bioremediation. To achieve accurate results, the maintenance of an optimal functional range is necessary. Technological advancements have led to new remediation techniques, i.e., nanobioremediation. This review includes insights on the impacts of azo dyes; the principles of bioremediation and its strategies, advantages, and limitations; and future prospects involving nanobioremediation.
... Natural dyes obtained from different plants, animal and minerals resources. Natural colorant is an important group of non-wood forest products which find use in industries producing food products, textiles, cosmetics, medicines, paint, ink, etc. Considering the risks to the environment, human health and sustainability issues relating to the synthetic dyes, there has been a reignited global interest in natural dyes, which are eco-friendly and non-toxic (Ahlström, 2005). ...
This study aims to evaluate the natural pigment extract from red dragon fruit for application in cosmetics. Aqueous extraction from both pulp and peel of red dragon fruit were performed by varying extraction temperature. The color pigment content was determined based on the absorbance using Ultraviolet-visible (UV-Vis) at 535 nm. The result shows that the color intensity decreased with increasing temperature. In addition, the extract shows decreased in total betacyanin content over time as it exposed to light. The extracts were powdered with corn starch and white clay and the stability of obtained color powder was studied. In conclusion, the natural pigment extracted from red dragon fruit using water as a solvent has a high potential to be used as a natural colorant.
... In recent years, the textile industry in particular has come under a lot of environmental criticism. As a result, environmental and economic restrictions have been placed on the chemicals used, up to and including bans [101]. Specific concepts where plant-based compounds can be used in textile finishing that are environmentally friendly, biocompatible, low toxic, and sustainable have become very fashionable in recent years [102]. ...
Sustainability aims to provide a livable future for the next generations. Studies on reducing high chemical, energy, and water consumption make significant contributions to sustainability in many sectors. The textile sector consists of many processes such as fiber production, yarn and fabric production, dyeing, and finishing processes. Each of these processes consumes a significant amount of water and energy. Cotton fiber production consumes approximately 1559 kg of fresh water per kg, and polyester fiber production consumes approximately 108 kWh of electricity per kg. Clean water consumption can be up to 200 L/kg in subsequent processes such as bleaching, dyeing, printing, and finishing. Surface modification techniques in textile production can play a role in sustainability, especially in areas such as reduction, reuse, and recycling. In this chapter, we aim to investigate the effects of surface modification techniques on reducing chemical, energy, and water consumption in textile production, improving textile performance properties, and altering the service life of textiles.
... 4 While natural dyes tend to be unstable and easily degrade during food processing, synthetic dyes are more commonly employed due to their stability. 5 However, it is important to note that certain synthetic dyes can have adverse effects on human health, including allergies, headaches, hyperactivity, and abdominal pain. 6 The color of a product signicantly inuences its appeal to consumers, and sunset yellow (SY, CHN 2 Na 2 O 7 S 2 ) is a commonly used synthetic azo dye in beverages and foods. ...
Sunset Yellow (SY) is a widely used food coloring in the food industry. However, exceeding the allowable limit of this dye poses a significant threat to human health. To address this issue, we developed the Lycium Ruthenicum-derived nitrogen-doped carbon dots (N-CDs) with a stable blue fluorescence through hydrothermal treatment for SY determination. The quantum yield (QY) of these N-CDs was found to be up to 10.63%. Physical characterization of the N-CDs was performed using various spectroscopic techniques to confirm their excellent photostability and non-toxic properties. Furthermore, the presence of SY had a substantial quenching effect on the fluorescence intensity (F0/F) of the N-CDs. Leveraging this observation, we developed a fluorescent sensor for SY determination in the concentrations of 0.05 to 35.0 μM, with a limit of detection (LOD, 3σ/K) of 17 nM. The excellent fluorescent sensor also performed satisfactory results in the practical drink samples. Meanwhile, the stability and cytotoxicity of N-CDs as a fluorescent probe were also studied. Finally, the N-CDs were applied to cell imaging using A549 cells.
... These are banned by EU regulation authority. [5][6][7][8] The hazardous nature of these arylamines has already been reported. [1][2][3][4] Various studies have been carried out for determining arylamines in leather and textiles, [9][10][11][12][13][14][15] dyes, 16 toys, 17 water 18 and food. ...
Arylamines present in leather and textile products are reduced in vivo by cleavage of azo groups to form highly mutagenic and carcinogenic products that pose consumer’s health risk. The major textile and leather products that are offered to consumers need to be safe. In order to ensure safety as per the global regulations, the allowed limit of carcinogenic amines in textile and leather products cannot be more than 20 mg/kg. There are several methods that have been used for extracting the azo dyes and analyzing them in textile and leather products. Most of these methods are polluting from high solvent usage, time consuming, laborious, and have lower recovery rates. In the present study QuEChERS method, (dispersive solid phase extraction-dSPE) method was utilized for extraction of carcinogenic arylamines from dyed leather and textile products. The released arylamines are extracted into acetonitrile using QuEChERS salt and analyzed by Ultra Performance Liquid Chromatography-Photo Diode Array (UPLC-PDA). The extracted product was further confirmed by Gas Chromatography-Mass Spectrometer (GC-MS). The method proposed in this study is novel as it eliminates all significant concerns associated with the official ISO-17234-1 &14362-1 test methods, such as use of solvents like tert-butyl methyl ether (MTBE) and the long duration of analysis. The sample preparation time is minimized from 120 min to 20 min. The developed method is easy to adopt with efficient recovery rate of arylamines in comparison to the official ISO method.
... This can cause severe environmental pollution, as these dyes are often toxic and can harm aquatic life. Consequently, many countries have imposed strict bans on goods containing these dyes (Ahlström, Eskilsson, and Björklund 2005). Therefore, there is a high demand for greener alternatives. ...
A sustainable one-bath dyeing and functionalization process of cotton fabrics with pomegranate rind and onion peel extract using chitosan (CS) biomordant was investigated. Liquid chromatography-mass spectrometry was used to verify the presence of the main colorants, ellagic acid and quercetin, in the prepared extracts of pomegranate rind and onion peel. CS mordanting improved the color strength and wash fastness of pomegranate rind and onion peel dyed fabric by up to 36% and half a rating point, respectively. CS significantly enhanced the UV protection (UPF 50+) and antimicrobial activity (ranges from 93.8 to 99.9%) of dyed fabric. Chitosan mordanting improved the bending rigidity and compression recovery of the cotton fabric, but it also reduced the handle and flexibility of the treated fabrics owing to the formation of CS layer on the cotton fabrics. The dyed fabric also showed remarkable deodorizing (above 80%) and antioxidant (above 90%) properties. Overall, the proposed process could be a sustainable and economical alternative to the conventional metal mordant process.
... The betaglucosidase enzyme contained in the chloroplasts of the mesophyll cells of the leaves of this indigo would result in colorless water-soluble indoxyl and these indoxyl compounds, when oxidized by oxygen in the air, would change to indigo blue compounds that is blue but insoluble white ready to be color for dyeing process. Ahlström, Eskilsson, and Björklund (2005) also noted that the color extraction in Thailand commonly adds various types of alkaline into fermented mixture in order to separate the color paste from the fermented leaves. The solution is left for one night for the blue color paste to be bound to lime. ...
This study investigates the color values and colorfastness of silk fabrics dyed with dye extracted from Water Jasmine (Wrightia religiosa Benth.) using three different alkaline agents: red lime, lime, and sodium carbonate. The color values (L*, a*, b*, C*, h*, and K/S) were measured before laundering to evaluate the color characteristics of the dyed silk. Notably, red lime produced the deepest shade (L* value of 50.46), closely followed by lime (77.07) and sodium carbonate (59.48). The h* values indicated that red lime (246.83) and sodium carbonate (292.17) produced blue shades, while lime (92.54) leaned toward green-yellow. Regarding color strength (K/S), red lime and sodium carbonate exhibited the highest color strength (1.74), whereas lime had the lowest (0.59). After laundering, colorfastness was evaluated using DL*, Da*, Db*, DC*, DH*, and DE* values. Red lime showed the best color durability, with a DE* value of 6.46, indicating fair color retention. Lime and sodium carbonate had poorer color durability, with DE* values of 12.05 and 16.15, respectively. Thus, the results clearly show that Water Jasmine with red lime possesses significant potential for development as a natural dye source, specifically for creating novel blue-colored natural dye material for silk dyeing.
... The growth of the textile industry leads to an increase in the chemicals used in textile processing, and the market value of it is estimated to be 31.8 billion USD by the end of 2026. 6 Several studies on the presence of chemicals in textile products (Ahlström et al., 2005;Herzke et al., 2012;Kajiwara et al., 2009) have been carried out over the past few years, including those on NPs and NPEOs 7,8 . ...
This report discusses issues surrounding the presence of Nonylphenol Ethoxylates (NPEOs) in textile products available for sale in the Indian market, based on the study conducted by Toxics Link. NPEOs are primarily used as surfactants and detergents
during the manufacturing of textile products, potentially resulting in their release from manufacturing facilities. The residues of NPEOs can also be retained in the finished textile products and subsequently released during washing, posing significant environmental and health risks. Once released, they break down to form nonylphenols (NPs), which are known to be toxic, act as hormone disruptors, and are persistent and bioaccumulative.
... Alternative methods are being developed to reduce the damage caused by synthetic dyes, which are often used in dye houses. The cationization process used to reduce waste loads in cotton dyeing, the use of impregnation instead of pulping in aqueous processes, or the use of natural dyes instead of synthetic dyes are some of these methods [7][8][9][10]. These methods are particularly important for avoiding the damage caused by synthetic dyes and for sustainable production. ...
The world in which we live is changing at a much faster and more uncontrolled rate. This situation brings with it both negative and positive changes. The textile industry is also part of this rapid change. The growth of the world’s population and the alterations in consumer habits that this change has brought with it also affect the textile industry. In particular, polluting dyehouses and the synthetic dyes used in them are harming the world. This situation is unsustainable. For this reason, the use of natural dyes instead of synthetic dyes in the coloring of textile products is increasing rapidly. In this study, a blend of 80% cotton and 20% wool was dyed with cinnamon, and its fastness and mechanical performance were tested. In addition, the dyeing results were analyzed using a spectral method, FTIR, and SEM. In this study, natural fiber blends with two different chemical structures were dyed with cinnamon in one bath. The fastness values obtained as a result of the dyeing process were very good. The grey scale value of saliva fastness determined through evaluation was 5. The observed strength increase of approximately 24% in the yarn after dyeing was also remarkable. In conclusion, environmentally friendly dyeing was carried out in this study, and a contribution was made to a sustainable world.
... Aromatic amines are important industrial chemicals used as raw materials for dyes and pigments and used all the time in our daily lives. Indeed, over 3000 varieties of azo dyes are used in leather, clothing, foods, toys, cosmetics, and other products sold around the world (Ahlström et al. 2005). Several epidemiological and experimental studies have suggested that some aromatic amines, such as o-toluidine and o-anisidine, are associated with the risk of bladder carcinogenesis (Cumberbatch et al. 2015;Nakano et al. 2018). ...
Although aromatic amines are widely used as raw materials for dyes, some, such as o-toluidine and o-anisidine, have shown concerning results regarding carcinogenicity in the urinary bladder. We have recently developed a short-term detection method for bladder carcinogens using immunohistochemistry for γ-H2AX, a DNA damage marker. Here, using this method, we evaluated aromatic amines with structures similar to o-toluidine and o-anisidine for bladder mucosal damage and potential carcinogenicity. In total, 17 aromatic amines were orally administered to male F344 rats for 28 days, and histopathological examination and γ-H2AX immunostaining of the urinary bladder were performed. Histopathological analysis revealed that seven aromatic amines, including 4-chloro-o-toluidine (4-CT), o-aminoazotoluene, 2-aminobenzyl alcohol (ABA), o-acetotoluidine (o-AT), 3,3ʹ-dimethoxybenzidine, 4-aminoazobenzene (AAB), and 4,4′-methylenedianiline (MDA), induced various bladder lesions, such as hemorrhage, necrosis, and urothelial hyperplasia. The morphological characteristics of mucosal damage induced by these substances were divided into two major types: those resembling o-toluidine and those resembling o-anisidine. Six of these aromatic amines, excluding MDA, also caused significant increases in γ-H2AX formation in the bladder urothelium. Interestingly, 4-CT did not cause mucosal damage or γ-H2AX formation at the lower dose applied in previous carcinogenicity studies. These results showed for the first time that o-AT and ABA, metabolites of o-toluidine, as well as AAB caused damage to the bladder mucosa and suggested that they may be bladder carcinogens. In addition, 4-CT, which was thought to be a noncarcinogen, was found to exhibit bladder toxicity upon exposure to high doses, indicating that this compound may contribute to bladder carcinogenesis.
... Synthetic dyes are deliberately designed to resist aerobic degradation, although they are susceptible to degradation under anaerobic conditions [13]. These substances are known or suspected carcinogens, presenting a significant health risk to both humans and other living organisms [14]. Among the numerous dye pollutants, Rhodamine B (Rh-B) is particularly notable as a commonly used cationic dye belonging to the xanthene dyes category. ...
... Among the synthetic dyes used in the food industry, azo dyes, which are synthetic organic dyes containing an azo group as part of their structure, are widely used and account for ~ 65% of the commercial dye market (Ahlström, Eskilsson, & Björklund, 2005). Azo dyes are used as a colorant in various food products such as jams, candies, confectionery, ice cream, jellies, alcoholic beverages, and soft drinks. ...
This study aims to develop and validate a method for simultaneously measuring three azo dyes (azorubine, brilliant black BN, lithol rubine BK) not designated in Korea. The HPLC-PDA analysis method was validated based on the ICH guidelines, and the color stability was evaluated. The milk and cheese samples were spiked with azo dyes, the correlation coefficient of calibration curve ranged from 0.999 to 1.000 and the recovery rates of azo dyes were 98.81 ∼ 115.94%, with RSD of 0.08 ∼ 3.71%. The LOD and the LOQ in milk and cheese ranged from 1.14 to 1.73 μg/mL and 3.46 to 5.25 μg/mL, respectively. In addition, the expanded uncertainties of the measurements ranged from 3.3421 to 3.8146%. The azo dyes appeared to be color stable for more than 14 days. The results indicate that this analytical method is suitable for extracting and analyzing azo dyes in milk and cheese samples, which are not permitted in Korea.
... (b) FTIR spectrum of collagen in interaction with Sunset Yellow The interaction of food dyes with collagen [45,70] can be studied by FTIR spectroscopy. Sunset Yellow belongs to the azoic group of dye compounds, from which, by the interaction with the environment where they are processed and employed, is possible formation of carcinogenic aromatic amines and amides [1,[71][72][73][74][75][76][77][78][79][80]. ...
... (b) FTIR spectrum of collagen in interaction with Sunset Yellow The interaction of food dyes with collagen [45,70] can be studied by FTIR spectroscopy. Sunset Yellow belongs to the azoic group of dye compounds, from which, by the interaction with the environment where they are processed and employed, is possible formation of carcinogenic aromatic amines and amides [1,[71][72][73][74][75][76][77][78][79][80]. ...
The general population may be exposed to benzidine through contact with leather products, clothing, and toys containing benzidine or benzidine-based paints. The food dyes tartrazine and sunset yellow contain trace amounts of benzidine (within nanograms per gram of food). The production and use of benzidine in the production of paints has been recorded in some developing countries. Exposure to benzidine through ingestion is unlikely, but other impurities in synthetic dyes may be metabolized to benzidine after ingestion. Benzidine causes bladder cancer. Its urinary metabolites are benzidine and benzidine conjugates (monoacetylbenzidine).
Visually appealing foods are often associated by consumers with subjective quality features, such as freshness, palatability, and shelf life. In the past, there have been repeated violations in which regulations on the use of pigments in food were ignored and/or unauthorized or toxic dyes (e.g., Sudan red in paprika powder) were added. Most recently, adulterations by using reactive dyes from the textile sector have been reported. These included, among others, colored spice preparations for use in meat products (e.g., for sausages and meat products), which were advertised to contain natural plant-derived pigments mainly consisting of betalains and/or anthocyanins. In contrast to natural dyes, reactive dyes are very stable toward extreme pH values, heat, and light. Due to their chemical properties, reactive dyes cannot be detected by classical dye analysis as they may be covalently bound to the food matrix. Methods for the analysis of matrix-bound reactive dyes are therefore required. In this study, a reductive cleavage method of bound textile dyes in different food matrices (spice mixtures, fruit juices, and scalded sausages) and the detection of characteristic cleavage products after enrichment by solid phase extraction (SPE) and liquid chromatography-electrospray ionization-tandem mass spectrometric (LC-ESI-MS/MS) analysis is reported. In addition, 13 suspicious samples provided by project partners were analyzed using the newly developed LC-ESI-MS method.
In the present work, five monoazo heterocyclic disperse dyes PY1–PY5 were synthesized in good yield. A 2-amino-3-hydroxypyridine was used as a coupling component with five distinct heterocyclic diazonium salts. All the dyes are new except the dye PY4. The obtained colorants were characterized by melting point, 1H-NMR, FT-IR, UV–Vis, FAB-LRMS, and FAB-HRMS. The main skeletons of the dyes PY1, PY3, and PY4 were further confirmed by 13C-NMR (BB), 1H–1H COSY, 1H–13C HSQC, and 1H–13C HMBC. The effect of pH variation on the λmax of these colorants was assessed in methanol and DMSO. Their solvatochromism analyses were performed in various organic solvents, e.g., acetic acid, methanol, acetone, acetonitrile, dimethyl sulfoxide, and dimethyl formamide. The geometries of the dyes were optimized at the B3LYP/6-311G (d,p) level, and their electronic excitation properties were determined using time-dependent density functional theory. The computed data were in good agreement with the experimental data. These colorants were applied to polyester fabric as disperse dyes and evaluated for build-up study along with complete observation of their fastness to water, washing, sublimation, rubbing, perspiration, and light. The antimicrobial exploration of these dyes was performed in detail against human pathogenic fungi including Aspergillus fumigatus, Candida glabrata, Candida albicans and Trichophyton rubrum. The dye PY5 was found to have promising inhibition against all the human pathogenic fungi used.
Switchable hydrophilicity solvent liquid-liquid microextraction (SHS-LLME) was employed as a sample pretreatment method to enrich and pre-concentrate the dye Tartrazine (Tz) before its quantification using UV-visible spectrophotometry. N-methyl dipropyl amine (MDPA) was used as the extraction solvent. The key parameters of the SHS-LLME process were optimized using central composite design (CCD) and response surface methodology (RSM) to evaluate the interactive effects of the three most critical operational variables. The interactions between the MDPA, HCl, and NaOH volume on dye absorption were studied. The LOD and LOQ (n = 7) were calculated as 0.23 μg/mL and 0.692 μg/mL, respectively. The method showed a relative standard deviation (RSD) of 1.71% for 10 replicate measurements. Enrichment and preconcentration factors were determined to be 63 and 33.33, respectively, demonstrating the method’s effectiveness in enhancing Tartrazine detection.
Transforming waste industrial sludge into biocomposite materials for dye adsorption presents a sustainable approach to waste management and water purification, as explored in this comprehensive review. Despite its potential, standardization in biocomposite preparation and understanding the effects of various factors on adsorption efficiency are challenging. The long-term stability, reusability, and inferior adsorption capacity compared to commercial adsorbents, along with production scalability and economic concerns, are key limitations. Overcoming these requires interdisciplinary collaboration and enhanced performance, stability, and cost-effectiveness. Limited industrial applications and regulatory frameworks further impede widespread adoption. Advancements in this area depend on industry engagement, regulatory support, and research, particularly in understanding chemical interactions within biocomposites, to establish them as effective solutions for reducing dye pollution and enhancing environmental sustainability.
في وقتنا الحالي يتزايد الطلب على الملونات التي قد تكون ضارة عندما تكون ملونات صناعية لتلوين مُختلف الأطعمة
ومنها العصائر والمشروبات الغازية المختلفة، لدعم لون المنتجات والتأثير على حواس المستهلك والتي تلعب دوراً حاسماً
في تسويق المنتج، من بين الأعداد الكبيرة من المواد المستخدمة في التلوين والأصباغ الاصطناعية المنتشرة في هذه
الصناعة. صبغة السودان رد B صبغة حمراء اللون والتي استخدمت في الصناعة وخاصة إنتاج صبغات الشعر
والمستحضرات التجميلية، ولا تزل بعض البلدان تستخدمها كمضافات غذائية رغم حظر استخدامها في صناعة المواد
الغذائية بسبب تأثيرها المحتمل للسرطان. وتم تصنيفها ضمن الفئة الثالثة للمواد البشرية المسرطنة من قبل الوكالة الدولية
لأبحاث السرطان. ومن المهم وصف آثارها الضارة على الصحة والمستهان بها في الوقت الحاضر. توجد طرق عديدة
للكشف عن وجود صبغة السودان رد .B وفي هذه الدراسة تم استخدام جهاز التحليل الطيفي للكشف عن وجود صبغة
السودان رد B عند طول موجي 525 نانومتر في عينات متنوعة من العصائر والمشروبات الغازية من بلدان مختلفة
الصنع والمتوفرة في الأسواق المحلية الليبية.
الكلمات المفتاحية: صبغة سودان رد B ، صبغة السودان في العصائر، الملونات الغذائية، التحليل الطيفي.
في وقتنا الحالي يتزايد الطلب على الملونات التي قد تكون ضارة عندما تكون ملونات صناعية لتلوين مُختلف الأطعمة
ومنها العصائر والمشروبات الغازية المختلفة، لدعم لون المنتجات والتأثير على حواس المستهلك والتي تلعب دوراً حاسماً
في تسويق المنتج، من بين الأعداد الكبيرة من المواد المستخدمة في التلوين والأصباغ الاصطناعية المنتشرة في هذه
الصناعة. صبغة السودان رد B صبغة حمراء اللون والتي استخدمت في الصناعة وخاصة إنتاج صبغات الشعر
والمستحضرات التجميلية، ولا تزل بعض البلدان تستخدمها كمضافات غذائية رغم حظر استخدامها في صناعة المواد
الغذائية بسبب تأثيرها المحتمل للسرطان. وتم تصنيفها ضمن الفئة الثالثة للمواد البشرية المسرطنة من قبل الوكالة الدولية
لأبحاث السرطان. ومن المهم وصف آثارها الضارة على الصحة والمستهان بها في الوقت الحاضر. توجد طرق عديدة
للكشف عن وجود صبغة السودان رد .B وفي هذه الدراسة تم استخدام جهاز التحليل الطيفي للكشف عن وجود صبغة
السودان رد B عند طول موجي 525 نانومتر في عينات متنوعة من العصائر والمشروبات الغازية من بلدان مختلفة
الصنع والمتوفرة في الأسواق المحلية الليبية.
In recent years, natural dyes are gaining more attention as a sustainable and ecofriendly alternative to synthetic dyes. However, the use of toxic metal mordants make the natural dyeing process unsustainable. In order to make natural dyeing process truly sustainable, it is challenging to find alternative sources of mordant-like materials that are sustainable and ecofriendly. Chitosan, a natural resource, and a cost-effective cationic biopolymer could be a sustainable alternative to metal mordants. This paper provides an in-depth review of chitosan and its derivatives and discuss their potential role as a biomordant in natural dyeing of textiles. This review will help the academic readers to understand the basic mordanting mechanism of chitosan and its efficient application technique. Furthermore, the prospects and challenges of chitosan mordant in natural dyeing are also discussed.
The chapter discusses the social and environmental impacts of textile production, a significant global industry with significant impacts on labor practices, human rights, gender equality, community well-being, legal frameworks, and sustainability. Textile workers in underdeveloped countries face labor rights abuses, low pay, long hours, dangerous working conditions, and restricted access to healthcare and education. Gender discrimination is a significant issue, particularly for women. Poor work-life balance, financial inequality, and health issues are also prevalent among textile workers. The textile industry has a significant environmental impact, including solid waste production, water pollution, climate change, and air pollution. Water pollution is a major issue due to the industry's substantial water consumption and contamination with chemicals and colors. Air pollution is also a concern due to high noise levels and dust discharge during fiber processing. The textile sector contributes significantly to global greenhouse gas emissions, with over 10% of all emissions coming from this sector. Mitigation measures for the environmental impacts of the textile industry include embracing corporate social responsibility (CSR), promoting community well-being, adopting circular economy principles, exploring advanced production techniques, improving energy efficiency, reducing air pollution, implementing floating treatment wetlands for effluent treatment, and using bioremediation and gamma radiation for solid waste management. These strategies aim to reduce the industry’s ecological footprint, improve social and environmental responsibility, and use fewer resources.
Azo dyes have been extensively utilized in various industries, establishing themselves as the predominant organic dyes in global markets owing to their diverse color range, high tinctorial strength, and excellent color fastness. However, it is imperative to acknowledge the associated health risks, including allergies, cancers and mutations, attributed to azo dyes. In contrast, natural dyes possess low sensitization, biodegradability, and environmental friendliness, thereby exhibiting significant potential for replacing high-risk azo dyes. Flavonoids, natural compounds derived from plants, have been utilized in dyes, pigments, cosmetic products, and even foods. The extract from Acacia confusa heartwood has rich flavonoids, endowing good photostabilities to prevent wood from UV-induced degradation. However, the wood protection ability of these flavonoids would be shaded when exposed to UV light with heat and water, owing to their photo-chemical characteristics. These problems need to be solved if the A. confusa flavonoids are applyed as wood photostabilzers. Hence, this study is to explore the feasibility of extracts from A. confusa as natural dyes with wood photostability through mordant-dyeing process. The findings reveal that the heartwood extract and its ethyl acetate fractions, abundant in flavonoids and condensed tannins, can form chelated structures, exhibiting distinct colors when combined with CuCl2 and FeCl2. This results in the red-brown and dark brown appearance of wood, respectively. Significantly, the specimens treated with CuCl2- and FeCl2-mordanted heartwood extract demonstrate excellent color fastness against heat and water. Moreover, these extracts exhibit the ability to absorb UV light and neutralize free radicals, enhancing the UV light resistance of color fastness. As a result, the mordant-dyed extract not only contribute various colors to wood but also enhance their photo resistance by excellent photostability. These outcomes also pave the way for expanding the applications of A. confusa extracts and establish systematic methodologies for natural dyes applied on wood products.
Background
In today’s world, appearance is an important factor in almost all areas of our lives. Therefore, it has become common to use dyes to color foods to make them look appetizing and visually appealing. However, food additives have negative effects on biochemical processes in cells at both high and low doses.
Methods and results
This study investigated the effect of carmoisine, a commonly used food coloring, on oxidative stress and damage parameters in Drosophila melanogaster in terms of both enzymatic and gene expression. The change in mitochondrial DNA copy number (mtDNA-CN), a marker of oxidative stress, was also examined. When the data obtained were analyzed, it was observed that carmoisine caused a significant decrease in GSH levels depending on the increase in dose. SOD, CAT, GPx, and AChE enzyme activities and gene expression levels were also found to be significantly decreased. All groups also showed a significant decrease in mtDNA-CN. The effect of carmoisine on Drosophila melanogaster morphology was also investigated in our study. However, no significant change was observed in terms of morphological development in any group.
Conclusions
When all the findings were evaluated together, it was observed that carmoisin triggered oxidative stress and these effects became more risky at high doses. Therefore, we believe that the consumer should be made more aware of the side effects of azo dyes in food and that the type and concentration of each substance added to food should be specified.
Palm oil is one of the most widely consumed food products globally. Despite the restriction of Sudan dyes as a food colouring agent, these dyes still feature prominently in palm oil adulteration, which occurs in most developing countries. The current study aims to provide insight into the recent palm oil adulteration over 18 years and the methods for detecting this adulterant. By using the European Union's (EU) rapid alert system for food and feed (RASFF), data on palm oil adulterated with Sudan dye was extracted between the years 2004 to 2022 and analysed to determine their overall pattern. Adulteration of palm oil was categorised by the origin and concentration of various Sudan dyes. The results from RASFF could confirm a total of 204 cases of Sudan dye adulteration in palm oil. African countries recorded the highest number of alerts for exporting palm oil adulterated with Sudan dye to European countries. Additionally, 70 reported cases of palm oil adulteration were recorded in 2004 and this was a result of increased regular testing of Sudan dyes in foods within the EU community. Also, the concentration of Sudan IV dye was the highest in all the palm oil tested by the notifying countries, since it is highly soluble in crude palm oil compared to Sudan I, Sudan II and Sudan III. Finally, the results presented in this manuscript highlight the importance of the detection of Sudan dye adulteration in palm oil from 2004 to 2022 from the RASFF database. The techniques frequently used for analysing palm oil included gas chromatography mass spectrometry (GC-MS), gas–liquid chromatography (GLC), reversed-phase high-performance liquid chromatography (RP-HPLC), high performance liquid chromatography (HPLC), differential scanning calorimetry (DSC), NIR spectroscopy, MIR spectroscopy, FTIR spectroscopy, Raman spectroscopy, surface enhanced Raman spectroscopy (SERS), and electronic tongue. Among the methods reviewed, HPLC and GC-MS were frequently used; however, rapid non-destructive methods such as spectroscopic techniques for the onsite Sudan dye detection in palm oil would be very beneficial for many palm oil-producing countries in Africa.
The escalating global concern over water pollution, predominantly propelled by industrial activities, underscores the urgency for effective environmental remediation strategies. Of particular, concern is the discharge of synthetic colorants into water bodies, a prevailing issue notably pervasive in textile industries. Azo dyes, ubiquitous in various industrial sectors, including food and textile manufacturing, constitute a significant portion of dye-contaminated wastewater, thereby contributing to soil and water pollution, especially in emerging and economically challenged nations. The deleterious impact of azo dyes on human health and aquatic ecosystems heightens the urgency of addressing this environmental menace. In response to the imperative need for mitigating the adverse effects of azo dyes on the environment, human health, and natural water resources, a spectrum of physio-chemical technologies has been proposed for azo dye degradation. However, a noteworthy paradigm shift toward environmentally friendly approaches is increasingly imperative. This comprehensive review critically examines various strategies employed for the degradation of Acid Orange 7, a representative azo dye, encompassing physical, chemical, and biological interventions. In the realm of biological treatment, the focus is predominantly on microorganisms such as fungi, yeast, bacteria, and algae, which have emerged as promising agents due to their inherent eco-friendly nature. This article provides an in-depth exploration of microbial remediation strategies, highlighting recent advancements in degradation techniques and elucidating the intricate mechanisms underlying azo dye degradation by bacteria. This review aims not only to present a consolidated overview of existing technologies but also to underscore the importance of harnessing the potential of microorganisms in the treatment of azo-dye-containing wastewater. The comprehensive insights provided herein contribute to the evolving discourse on sustainable and environmentally benign approaches for mitigating the impact of azo dyes on global water resources.
Biological treatment using microorganisms is an alternative low-cost wastewater treatment method with minimal environmental impact. However, there have been few studies on such purification technologies in marine environments. Moreover, for practical application, an appropriate safety assessment accounting for the impact on the ecosystem is necessary. To fill this gap, the aim of this study was to evaluate the efficacy of the marine fungal strain Pestalotiopsis disseminata AN-7 isolated from mangroves in Iriomote Island (Okinawa, Japan) in decolorizing synthetic dyes in the presence of salt and the changes in ecotoxicity during the decolorization process. The acute inhibition test for the azo dye Reactive Red 120 (RR120) and the xanthene dyes Food Red No. 104 (FR104) and Food Red No. 105 (FR105) showed half-maximal effective concentrations of 20.6, 12.1, and 0.69 mg/L to inhibit swimming of Daphnia magna. Pestalotiopsis disseminata AN-7 showed decolorization ratios of 75.6%, 60.6%, and 96.6%, respectively, and decolorization was also visually verified. A maximum decolorization ratio of 89.3% was obtained for a mixture of the three dyes. After decolorization, inhibition rates significantly decreased from 81.7 to 1.7% for RR120, 83.3 to 40% for FR104, 100 to 25% for FR105, and 100 to 18.3% for the dye mixture. High decolorization ratios (59.1–96.0%) were also maintained under NaCl concentrations of 1.5–3%. This study confirms the usefulness and safety of microorganisms for marine bioremediation in decolorizing synthetic dyes, even in the presence of salt and high dye concentrations, and further highlights the importance of acute toxicity assessments.
Objectives
Mouthwashes, a cornerstone of oral and dental hygiene, play a pivotal role in combating the formation of dental plaque, a leading cause of periodontal disease and dental caries. This study aimed to review the composition of mouthwashes found on retail shelves in Turkey and evaluate their prevalence and side effects, if any.
Methods
The mouthwashes examined were sourced from the 5 largest chain stores in each district of Istanbul. A comprehensive list of the constituents was meticulously recorded. The research was supported by an extensive compilation of references from scholarly databases such as Google Scholar, PubMed, and ScienceDirect. Through rigorous analysis, the relative proportions of mouthwash ingredients and components were determined.
Results
A total of 45 distinctive variations of mouthwashes, representing 17 prominent brands, were identified. Amongst the 116 ingredients discovered, 70 were evaluated for potential adverse effects and undesirable side effects. The aroma of the mouthwash (n = 45; 100%), as welll as their sodium fluoride (n = 28; 62.22%), sodium saccharin (n = 29; 64.44%), sorbitol (n = 21; 46.6%), and propylene glycol (n = 28; 62.22%) content were the main undesireable features.
Conclusions
The limited array of mouthwashes found on store shelves poses a concern for both oral and public health. Furthermore, the intricate composition of these products, consisting of numerous ingredients with the potential for adverse effects, warrants serious attention. Both clinicians and patients should acknowledge the importance and unwarranted side effects of the compnents of the mouthwashes.
With the awareness of the negative effects of synthetic products on the environment and human health, there is a global search for environmentally, friendly and sustainable consumer products with natural dyes. The concept of naturalness gains importance for textile products that are in direct contact with human body. Therefore, dyeing process of cellulosic based fabrics in different colours with natural dyes has been developed. In this study, cotton fabrics were dyed in different colours at 1% and 3% concentrations by pre-mordanting with a cationic mordanting agent, and the washing fastness of the fabrics was tested. Before dyeing the fabrics were pre-treated and made sustainable for dyeing. Tube dyeing was performed with five different commercial natural dyes at different concentrations using the HT dyeing technique. Cotton fabrics structures in different colours were obtained by using a thickening agent in dyeing and a colour chart that could be presented to the market was created. In the studies carried out, it was observed that the fastness results were quite good in the acceptable value range (3-5), although there were dyeing defect, especially in dark dyed fabrics. It was determined that the prepared dyes should be filtered in order to minimize the dyeing defect.
The discharge of effluents from the textile industries to aqueous bodies is currently one of the biggest concerns of environmentalists. Dyes used in the textiles industries create pollution in the environment. The application of biological treatments is one of the most economically viable systems to decolorized effluents using bacterial isolates (TBSP, TBSP2). In this sense, studies were carried out tests for the removal of colour of Congo red, Methyl orange, Brilliant Blue, using bacterial strain. Firstly, all two bacterial strains were isolated from different environments. Then, tests were performed to verify which concentration of the dye would be limit for the growth of each microorganism. In addition to decolourization tests, other parameters such as pH, biomass, total proteins and toxicity of the metabolites formed were also monitored. The bacterial strain, isolated from the river environment, was able to decolourization concentrations of 100ppm to upto 700ppm respectively for the, Coomasie Brilliant blue, Methyl orange and Congo red. TBSP1 and TBSP2 discoloured respectively at concentrations 100ppm to 700 ppm , while the intercropping (consortium) of the two bacteria discoloured at a concentration of 700ppm for the three dyes tested individually. In these cultivation conditions, the decrease in the quality rate varied with the lowest rate observed in the assay containing Congo Red and Congo red dye and the highest removal rate in the assay containing the intercropping and the CBBR dye. The results shows that the bacteria biotechnological potent bacteria present initial pot in the decolourization of textile dyes, initial pot were shows the ability to decolorize azo dyes.
Dyes are widely used in the food. Limitations on their use have been imposed by regulating agencies. Since most dyes are harmful and carcinogenic, their use in food is no longer allowed. Typically these analyses require enrichment since the dyes are present at low concentrations. Various preconcentrations methods are used to ensure quality and safety that include single-drop microextraction, dispersive liquid-liquid microextraction, hollow fiber liquid phase microextraction, homogeneous liquid-liquid microextraction, solid phase microextraction, vortex assisted liquid- liquid microextraction, and ultrasound assisted liquid- liquid microextraction. The determination food dyes by various microextraction methods with high enrichment factors and good sensitivity are reviewed. The separation-enrichment methods are discussed to illustrate their advantages and limiations.
Microwave-assisted extraction (MAE), Soxhlet, sonication, and supercritical fluid extraction (SFE) were compared in their ability to extract 95 compounds listed in U.S. Environmental Protection Agency Method 8250. Freshly spiked soil samples and 2 standard reference materials were extracted with hexane-acetone (1 + 1) by MAE and Soxhlet extraction, with methylene chloride-acetone (1 + 1) by sonication extraction, and with supercritical carbon dioxide modified with 10% methanol by SFE. Results indicate that MAE is a promising extraction technique. Of 94 compounds for which we are reporting data, 51 compounds gave MAE recoveries of >80%; 33, 50-79%; 8, 20-49%; and 2, <19%. Soxhlet extraction gave very similar results: 50 recoveries were >80%; 32, 50-79%; 8, 20-49%; and 4, <19%. Sonication recoveries were slightly higher: 63 values were >80%; 25, 50-79%; 4, 20-49%; and 2, <19%. SFE re coveries were the lowest: 37 values were >80%; 37, 50-79%; 12, 20-49%, and 8, <19%. MAE gave the best precision: relative standard deviations (RSDs) were ≤10% for 90 of 94 compounds. Soxhlet extraction gave the worst precision: only 52 of 94 samples gave RSDs ≤10%. Although MAE looks promising, 15 polar basic compounds extracted at 115°C with hexaneacetone for 10 min (1000 W power) gave poor recoveries. Because no technique gave acceptable recoveries for these polar compounds, we investigated their extraction with MAE using acetonitrile at 50° and 115°C. Ten of the 15 compounds were quantitatively recovered (>70%) with acetonitrile at 115°C.
A rapid and simple method, pyrolysis gas chromatography coupled with mass spectrometric detection (Py-GC-MS), is introduced
for qualitative determination of banned aromatic amines released from azo dyes on textiles. Use of Py-GC-MS can reduce absolute
analysis time from three hours to thirty minutes, because no sample preparation is necessary. Qualitative determination of
banned amines by Py-GC-MS was investigated for three pure azo dyes and six contaminated textile samples consisting of different
matrices. Pyrolysates of pure azo dyes were identified as aromatic amines. Banned aromatic amines released from azo dyes could
be qualitatively determined for four of six contaminated textile samples by Py-GC-MS.
We recently reported that alpha 6 integrin mediates experimental metastasis in mice by functioning in the adhesion of tumor cells to the vascular endothelium. In the current study, we investigated the expression of human alpha 6 integrin in invasive breast carcinomas of 119 women. In 50% of the tumors alpha 6 integrin was expressed in the majority of the cells, and this expression was correlated with reduced survival time. By contrast, the 24% of patients with breast tumors devoid of alpha 6 integrin expression all survived. The tumors were also evaluated for clinical risk factors including histological grading and steroid receptor level. The combination of these factors with alpha 6 integrin expression was superior in predicting overall survival than considering the other factors alone. The correlation with decreased survival time was consistent, regardless of whether the tumors expressed the alpha 6 integrin A or B forms, which differ in their cytoplasmic domain. On the basis of this pilot study we consider alpha 6 integrin expression to be a novel prognostic marker for human breast cancer.
Azo dyes represent the major class of dyestuffs. They are metabolised to the corresponding amines by liver enzymes and the intestinal microflora following incorporation by both experimental animals and humans. For safety evaluation of the dermal exposure of consumers to azo dyes from wearing coloured textiles, a possible cleavage of azo dyes by the skin microflora should be considered since, in contrast to many dyes, aromatic amines are easily absorbed by the skin. A method for measuring the ability of human skin flora to reduce azo dyes was established. In a standard experiment, 3x10(11) cells of a culture of Staphylococcus aureus were incubated in synthetic sweat (pH 6.8, final volume 20 mL) at 28 degrees C for 24 h with Direct Blue 14 (C.I. 23850, DB 14). The reaction products were extracted and analysed using HPLC. The reduction product o-tolidine (3,3'-dimethylbenzidine, OT) could indeed be detected showing that the strain used was able to metabolise DB 14 to the corresponding aromatic amine. In addition to OT, two further metabolites of DB 14 were detected. Using mass spectrometry they were identified as 3,3'-dimethyl-4-amino-4'-hydroxybiphenyl and 3, 3'-dimethyl-4-aminobiphenyl. The ability to cleave azo dyes seems to be widely distributed among human skin bacteria, as, under these in vitro conditions, bacteria isolated from healthy human skin and human skin bacteria from strain collections also exhibited azo reductase activity. Further studies are in progress in order to include additional azo dyes and coloured textiles. At the moment, the meaning of the results with regard to consumer health cannot be finally assessed.
The proclamation of 15 July 1994 of the German law concerning consumer goods, which prohibits dyes that, after the processes of reductive cleavage give certain aromatic amines, has necessitated the development of a methodology of analysis capable of dealing with the new legislation. In the present work on detection of arylamines, the influence of the conditions of the reducing agent/dye ratio, the pH of the medium, the reaction time and the temperature in the reduction process (sodium dithionite) of the azo dyes Direct Red 28, Acid Red 114 and Direct Blue 35 have been studied. It has been proved that the most suitable conditions for work can vary quite significantly from one dye to another, but if we use those conditions which are most extreme, we are assured in any case of the greatest possible yields of arylamines. Finally, it is reported that the maximum experimental concentration of arylamine obtained in each dye approximates quite well to the theoretical estimated values, which indicates that the yield of reductive cleavage of the azo group using sodium dithionite as a reducing agent is practically 100%.
The recent public awareness and consciousness about environmental protection followed by the strict Government regulatory orders in some countries on the manufacture and the use of dyes based on benzidine and its analogues due to their carcinogenicity and to the growing consumer preference for non-toxic materials have obliged the leather industry to use non-benzidine based dyes. This has necessitated the development of analytical techniques for distinguishing benzidine based dyes from non-benzidine based dyes. A gas chromatographic method using a mass selective detector for the unambiguous identification of benzidine dyes by recording the mass spectrum of the peak corresponding to the retention time of benzidine and quantification of benzidine by monitoring the peak area of the ion of 184 amu is described in this communication.
Azo dyes, which could be metabolised to carcinogenic aromatic amines as a result of reductive cleavage of the azo bond, must be considered as bearing a carcinogenic potential. A qualitative method is described for determining free amines, which are generated by azo cleavage for dyed leather, textile or paper samples.
High-performance thin-layer chromatography (HPTLC) on silica plates, with two successive mobile phases, has been used for analysis of seven amine azo dye isomers prohibited under a German ban. Dichloromethane was used for the first development, to a distance of 4.5 cm. After drying, the second development was performed with toluene-tetrahydrofuran, 10 + 1 (v/v), to a distance of 8.5 cm. Spots were visualized at λ = 254 nm. Eighteen amines have been studied by use of the method. The limit of determination (X) and the correlation coefficient in the range X to 5X are reported for each amine. To increase the sensitivity of detection, the UV spectrum was acquired for each amine and the wavelength of maximum absorbance (λmax) was used to establish the limit of determination. Synthetic mixtures and dye samples have been resolved and quantified.
A systematic evaluation of the parameters affecting the supercritical fluid extraction (SFE) of the following primary aromatic
amines was performed: 1,4-phenylenediamine, 2,4-diaminotoluene, benzidine, 4,4″-methylenebis(2-chloroaniline), 3,3″-dimethylbenzidine,
and 3,3-dichlorobenzidine. Nitrous oxide was utilized as the supercritical fluid, along with six different chemical modifiers.
The effect of modifier concentration was examined, as were the effects of pressure, extraction temperature, time, and volume.
1,6-Hexanediamine in methanol was demonstrated to be an effective SFE modifier. The extraction was optimized with a modifier
concentration of 5% in methanol, a pressure of 350 atm, three extraction volumes, and two modifier addition cycles.
A procedure for the simultaneous identification of seventy-three primary and secondary aromatic amines (including alkyl-, chloro- and nitro-substituted anilines, benzidines, aminoaphtalenes and aminobiphenyls) is described. The amines were derivatized by reaction with heptafluorobutyric anhydride to form the corresponding heptafluorobutyramides. The electrophoric derivatives were analyzed by gas chromatography combined with electron-capture negative-ion chemical ionization mass spectrometry. Linearity was satisfactory for all the compounds examined. Detection limits were in the range 0.3–66.3 pg the injected in full-scan acquisition mode and 0.01–0.57 pg injected in the selected ion monitoring acquisition mode. Application of the procedure to contaminated groundwater samples was also attempted.
Aromatic amines have been associated with the induction of cancer of the urinary bladder. Commercial production started over 100 years ago in Europe, with the synthesis of a mauve pigment from aniline. The discovery of other pigments by combining aniline with various chemicals initiated the aniline dye industry. By the turn of the century, a correlation between working in the dyestuff industry and the development of bladder cancer was established. Initially thought to be the result of exposure to aniline, various investigators identified benzidine, beta-naphthylamine, and 4-aminobipheny 1 as the causative agents. Evaluations of various aromatic amines in rats, mice, guinea pigs, rabbits, dogs, and monkeys showed significant species differences, with the dog and monkey being the most sensitive species. Several laboratories related these species differences to differences in the respective routes by which the various species metabolized aromatic amines. Excellent correspondence was shown between metabolic activation of benzidine, 4-aminobiphenyl, and beta-naphthylamine in dogs and primates and the induction of bladder cancer. Rodents were shown to be unresponsive to human bladder carcinogens. The need to use data developed in the most sensitive species, the dog, is essential to accurately predict the carcinogenic potential of aromatic amines.
Summary The German Ban on azo dyes prohibits the use of such dyes that release carcinogenic amines on reduction with sodium dithionate
in the presence of citrate buffer at pH 6. Of the amines in the list seven exist in isomeric forms. Isomers, being structurally
similar, show similar chromatographic properties and coelute, also, in most cases, mass spectra are identical. This can lead
to errors as only specific isomers of the amines are banned. A GC-MS method is described for identification of amines and
their isomers by derivatization with pentafluoropropionic anhydride (PFPA). Derivitization is by treating a solution of the
amine in tetrahydrofuran with PFPA at 60 C for 10 min. The amide derivatives formed are analyzed on a DB-5MS column in temperature
programming mode. The amines and their isomers show good resolution. From retention times and mass spectral data the various
amines and their isomers are identified and quantified. A total of 20 amines have been studied, limits of detection and relative
standard deviations (RSD%) for amines and derivatives are reported.
The method gave enhanced sensitivity, selectivity, improved peak shape, improved resolution and better detection limits.
Azo compounds, both symmetric and unsymmetric, are cleaved to amine(s) by using commercial zinc dust and ammonium formate or formic acid in methanol, tetrahydrofuran or dioxane at room temperature. The reductive cleavage occurs without hydrogenolysis or hydrogenation of reducible moieties, such as -OH, -CH3, -OCH3, -COOH, -COCH3, halogen, etc. The cleavage is very fast, clean, cost effective and high-yielding if compared with earlier methods, such as those using cyclohexene/5% Pd on asbestos, cyclohexene/10% PdC or hydrazine/10% PdC or Raney nickel.
This study concerns the possibilities of using microwave-assisted extraction (MAE) or supercritical fluid extraction (SFE) for detection of harmful azo colorants in leather. After degreasing of the leather sample with SFE there follows a reductive cleavage of the azo colorants to their corresponding aromatic amines in the MAE or SFE equipment. The aromatic amines are subsequently extracted using either MAE or SFE and then finally determined by liquid chromatography with diode-array detection. The results have been compared with recoveries obtained using the German DIN method 53316. This standard method, based on conventional solvent extraction, is used in several European countries. Overall much better recoveries were obtained using MAE or SFE. With both MAE and SFE the amine recoveries of spiked leather samples were generally above 50%. The average recoveries were 62% for MAE and 60% for SFE (solvent collection) compared to 24% with the DIN method. For genuine leather samples the recoveries decreased, especially for benzidine. In this case the average values for MAE, SFE and DIN were 54, 38 and 19%, respectively. The quantification limits in leather samples using MAE or SFE were below 1 mg/kg for all amines investigated. The within-laboratory precision was generally better than 10%, varying somewhat with the analyte considered. With the proposed methodology, the amount of hazardous organic solvents used could be decreased and the sample throughput increased with at least a factor of two with less manual handling compared to the DIN method.
The extraction of the following primary aromatic amines from soil samples was studied: 1,4‐phenylenediamine, 2,4‐diaminotoluene, benzidine, 4,4'‐methylenebis(2‐chloroaniline), 3,3'‐dimethylbenzidine, and 3,3'‐dichlorobenzidine. An extensive comparison of supercritical fluid extraction (SFE) with sonication extraction was performed. The SFE method yielded significantly higher recoveries and equivalent or better precision than sonication extraction for all eleven matrices studied. Characterization data for these matrices was evaluated to determine characteristics which affect primary aromatic amine recovery and to study the potential mechanisms involved in adsorption on the soil. It was determined that amine recovery was affected by the percent clay, the surface area, and the cation exchange capacity of the soil. Adsorption likely involves cation exchange groups including silanols on the surface of the clay materials in the soil.
Procedures were evaluated for the reductive cleavage of 16 commercial azo dyes using sodium hydrosulfite and tin(II) chloride. Identification of the reduction products were mainly based upon mass spectra obtained by particle beam high-performance liquid chromatography/mass spectrometry (HPLC/MS). Standards of the formed reduction products, when available, were employed to confirm identities. The chemical reduction methods resulted in nearly complete reduction of the azo bond to form aromatic amines. Overall, tin chloride was the more powerful reducing agent, yielding a greater number of products. The analysis of reduced industrial waste sludge extracts indicated the presence of identifiable aromatic amines which originated from the reduction of unknown dye components. While the identity of the parent dyes in these sludges could not be determined, this analytical approach appears to provide the means to assess the environmental significance of an effluent based on the presence of various amines. Therefore, reductive cleavage and HPLC/MS in tandem permits the screening of modern, complex synthetic dyes for potentially genotoxic aromatic amines without prior knowledge of the parent dye structure.
Procedures were evaluated for reductive cleavage of eight commercial azo dyes using hydrogen and palladium. The reduction was accomplished directly in a heated injector of a gas chromatograph (GC) with the resulting products separated by a capillary gas chromatography (GC) and characterized with a mass spectrometer (MS). This method resulted in nearly complete reduction of the azo bond to form aromatic amines. Standards of the formed reduction products, when available, were employed to confirm identities. For most of the tested azo dyes, the in-line H-2-Pd reduction/analysis procedure yielded the same or a greater number of reduced cleavage products than did reduction with SnCl2 in solution. The in-line reduction process was not affected by the presence of wastewater matrices. The GC/MS analysis of reduced waste sludge extracts indicated the presence of identifiable aromatic amines originating from the reduction of unknown dye components as well as other reducible nitrogen-containing compounds. While the identities of the parent dyes in these sludges were unknown, this analytical approach appears to provide a means to assess environmental significance of released effluent, based on the detection of potentially genotoxic aromatic amines.
A comparison of extraction methods for primary aromatic amines including 1,4-phenylenediamine, 2,4-diaminotoluene, benzidine, 4,4'-methylenebis(2-chloroaniline), 3,3'-dimethylbenzidine, and 3,3'-dichlorobenzidine from solid matrices was conducted. Supercritical fluid extraction(SFE) was evaluated and compared with the classical method, sonication extraction. Poor recoveries and precision were obtained with sonication extraction, even on control sand, and factors affecting this poor performance were examined. Significantly better recoveries and precision were obtained on control sand using SFE with either supercritical carbon dioxide or nitrous oxide as solvent. The effect of sample matrix on both extraction methods was examined. The classical method as well as traditional approaches with SFE were ineffective in extracting four of the six compounds from soil. Nitrous oxide modified with 1,6-hexanediamine In methanol was utilized in SFE of soil, resulting in significant improvement for all analytes studied.
A capillary zone electrophoresis (CZE) method for separating and detecting certain aromatic amines is described. In this study, the utility of this technique for monitoring dyes syntheses is also demonstrated. In addition to the analysis of amines, CZE can detect other impurities present in the starting materials used in dye synthesis. The influence of reaction conditions on the amount of carcinogenic amines liberated from azo dyes following sodium dithionite treatment is discussed.
Azo dyes are widely used in the food, pharmaceutical, cosmetic, textile and leather industries. They can be reduced by azoreductases in intestinal bacteria, liver cells and skin surface microflora so that aromatic amines are released. In this study an analytical system for the determination of carcinogenic aromatic amines at the picogram to femtogram level and a cell culture assay to evaluate the toxicological effects of azo dyes and aromatic amines is presented. For the assays, the commercial azo dye Resacor Blue 2F (Color Index: Direct Blue 15), a 3,3'-dimethoxybenzidine-based dye, was used. The released carcinogenic aromatic amine, 3,3'-dimethoxybenzidine, was extracted with diethylether derivatized with pentafluoropropionic anhydride and analyzed by capillary gas chromatography/mass spectrometry. In addition, the cytotoxicity of Resacor Blue 2F on cultured kidney epithelial cells and on two hepatocyte cell lines (Hep G2 and Chang liver) was evaluated. For this purpose, the cells were exposed for 72 h to varying concentrations of Resacor Blue 2F. The results show that the azo dye inhibits the proliferation of the kidney epithelial cells much more than the proliferation of the two hepatocyte cell lines. As calculated from the dose-response curves, the EC50 (effective concentration reducing cell proliferation by 50%) for kidney epithelial cells was 40 7g/ml, whereas the EC50 for both hepatocyte cell lines was more than 250 7g/ml. Higher concentrations of 3,3'-dimethoxybenzidine were found in kidney epithelial and in Hep G2 culture supernatants; only small amounts were found in the Chang liver culture supernatant. In summary, it was demonstrated that released 3,3'-dimethoxybenzidine was found in the cell culture supernatants, but it did not accumulate within the cells. For an interpretation of the toxicological results, cell-specific transport systems and osmotic effects of the commercial azo dye which contains several inorganic and organic additives has to be considered.
Aromatic amines or phenolic compounds at ppb levels in water were determined by on-line preconcentration with precolumn followed by high-performance liquid chromatography with UV absorption detection. This method was applied to the determination of aromatic amines or phenolic compounds at ppm levels in commercial dyestuffs. The dyestuffs was dissolved in water and precleaned with an SAX cartridge packed with an anion-exchange resin; the effluent was then analysed using the proposed on-line preconcentration and determination method.
The second amendment to ‘German Rugulations on Consumer Goods’ states that azo dyestuffs, which can release one or more of the listed 20 carcinogenic amines, should no longer be used in dyeing consumer goods. Many acid and direct dyes which liberate harmful amines such as benzidine, o-tolidine and o-dianisidine after reduction are, however, still use. In this study, it was surprising to find that some dyestuffs or dyed substrates released carcinogenic amines such as 4-amino-diphenyl, 2-naphthylamine, 2,4-toluenediamine and 4,4′-diaminodiphenyl-methane, although such amines had not been employed as intermediates in the manufacture of the dyestuffs. Benzidine was also detected from a dyestuff which was not made from benzidine. The 2-naphthylamine residues were sourced as being due to the use of 1-naphthylamine contaminated with 2-naphthylamine. 4-Aminodiphenyl was formed by dediazoniation and a subsequent coupling reaction between the benzenediazonium ion and aniline. Benzidine was derived from dediazoniation and a subsequent self-coupling reaction of the diazonium ion of 4-nitroaniline. 2,4-Toluenediamine and 4,4′-diaminodiphenylmethane arose from the alkaline hydrolysis of the readily accessible moiety of the corresponding base units in PU foams or PU finishing agents.
Epidemiological evidence on the relation between aromatic amines and cancer risk is reviewed. In particular, cancer risk in humans resulting from exposure to aromatic amines from occupational sources and tobacco smoking is assessed with reference to ecologic, cohort, and case-control studies. Seven arylamines have been classified by the International Agency for Research on Cancer: benzidine-based dyes and MOCA (4,4'-methylene bis 2-choloroaniline) were considered 'probably' carcinogenic, Group 2A, because of a high level of evidence in experimental animals; two occupational chemicals (2-naphthylamine and benzidine), one drug (Chlornaphazine), and two manufacturing processes (manufacture of auramine and magenta) were included in Group 1 on the basis of 'sufficient' evidence of carcinogenicity in humans. Occupational exposures to aromatic amines explain up to 25 percent of bladder cancers in some areas of Western countries; these estimates might be higher in limited areas of developing countries. Aromatic amines contaminate the ambient air as a component of environmental tobacco smoke. There is increasing evidence that the excess of bladder cancer in smokers is attributable to aromatic amines rather than to other contaminants of tobacco smoke such as polycyclic aromatic hydrocarbons (PAH). A modulating role in the risk of bladder cancer associated with exposure to aromatic amines is played by metabolic polymorphisms, such as the N-acetyltransferase genotype, raising important social and ethical issues. The consistent observation of a difference between men and women in bladder cancer risk, after allowing for known risk factors, suggests consideration of gender-related biological determinants for future investigation.
An ion-pair liquid chromatography method with on-line photodiode-array and electrospray mass spectrometry detection was developed to determine 10 commonly used sulphonated azo dyes (Tartrazine, Amaranth, New Coccine, Sunset Yellow FCF, Allura Red AC, Ponceau R, Ponceau 3R, Orange I, Orange II and Metanil Yellow) in food. A reversed phase C(18) column with gradient elution was utilized to separate these compounds. Triethylamine was added in the mobile phase as an ion-pair reagent for chromatographic separation. Photodiode-array detection was employed for quantitative determination and electrospray mass spectrometry was used for identification. Good linearity (0.05-10 ppm, r(2)=0.999) and detection limit (<0.01 ppm) were determined with 5 mul injection. In addition, precision and accuracy associated with this newly developed method will be presented. A liquid extraction method was also developed to extract these dyes from different foodstuffs. The application of this method was demonstrated by analyzing sulphonated azo dyes in soft drinks, fruit jam, and salted vegetables.
Utilizing elements of methodology developed previously for food colours, total free and bound non-sulphonated aromatic amines (NSAA) were determined in commercial samples of soft drink beverages and hard candies. Bound amines in the samples were reduced using sodium dithionite, then total NSAA were extracted into chlorofom, transferred to aqueous acid solution and diazotized with sodium nitrite before coupling with 2-naphthol-3,6-disulphonic acid, disodium salt (R-salt). The coloured derivatives were analysed using reversed-phase ion pair high-performance liquid chromatography (HPLC) and an absorbance detector set at 512 nm. Solid phase extraction cartridges were utilized for extraction and clean-up of the food colours present in the sample, and the concentration of each dye was determined quantitatively using HPLC and absorbance detector wavelengths of 426, 516 or 625 nm. Levels of total NSAA were compatible with those observed previously in food colours. Commercial soft drinks were found to contain (expressed in terms of total free plus bound NSAA in the beverage) 0.19-12.6 ng/ml of aniline, 0.83-8.25 ng/ml 1-naphthylamine and 0.62-1.12 ng/ml 2-naphthylamine. Levels of 0.66-9.15 ng/g of aniline and 2.48-10.6 ng/g 1-naphthylamine were found in commercial samples of hard candies. Bound NSAA in hard candies appeared to survive the manufacturing process. Recoveries averaged 96.9% for tartrazine and 89.6-97.2% for the bound amines when hard candies were prepared in the laboratory.
Aromatic amine and azo compounds are prevalent in the manufacture of common dyestuffs. The toxic actions of these substances are believed to be the result of metabolic activation and formation of labile products. Incubation techniques utilizing the liver microsomal fraction are a common method for studying the formation of these reactive intermediates. This study describes the use of liquid chromatography/electrochemistry (LCEC) for the determination of 4-nitroaniline, 2-amino-5-nitrophenol, and the labile N-hydroxy-4-nitroaniline in microsomal incubations. No prior extraction, preconcentration, or derivatization steps are necessary for the determinations which can be accomplished by a direct injection of the incubation. The dual-electrode detector in the parallel-adjacent configuration is used to confirm peak identity assignments. The series mode of this detector permits determination of 4-nitroaniline and its metabolites as products of the commonly used textile dye, Disperse Orange 3, in incubation media. Detection limits for the compounds of interest are all in the subpicomole range.
Various azo dyes currently approved by the US FDA for use in foods, drugs and cosmetics are reduced by anaerobic bacteria from the human intestinal tract. These bacteria with azoreductase activities include several Clostridium species. Seven of these azo dyes and their reduction products following incubation with a Clostridium sp. were evaluated for mutagenicity in Salmonella typhimurium strains TA98 and TA100. No mutagenicity was induced in either TA98 or TA100 by any of the seven azo dyes or the reduced metabolites when tested at concentrations as high as 200 microg/plate, with or without exogenous metabolic activation by rat liver fraction S-9.
A test method based on supercritical fluid extraction (SFE) and gas chromatography has been developed for some aromatic amines, such as 4-chloro-o-toluidine, beta-naphthylamine and 4-aminobiphenyl. A two-level factor design was used as the optimization procedure. Four main variables were considered: CO2 pressure, extraction temperature, static extraction time and volume of modifier (methanol). Results obtained for 4-chloro-o-toluidine, indicated that the volume of modifier was the variable with the most important influence on extraction, CO2 pressure had a negative effect and temperature and time were less significant. For the other amines, static time was the most important variable in both cases, followed by CO2 pressure and volume of modifier, with no influence of temperature. SFE was compared with Soxhlet extraction, and was found to give higher recoveries in all cases. Other commercial finger-paints were tested for the presence of aromatic amines.
A new method to detect the use of banned azo dyes in the manufacture and treatment of coloured textiles and leather is described. The determination of the azo dyes was made by quantification of aromatic amines generated by reductive cleavage in a citrate buffer medium. The aromatic amines were then extracted from 1 mL of the reaction solution by means of solid phase microextraction (SPME) and determined by gas chromatography/mass spectrometry (GC/MS). We also evaluate accuracy, precision, range of linearity and limit of detection for the eighteen aromatic amines investigated, and show that the method is comparable with current established methods. Copyright 1999 John Wiley & Sons, Ltd.
Several textile dyes were individually exposed to electrochemical treatment. Chromaticity variation and the formation of degradation products were followed using a UV spectrophotometer and HPLC with diode array detection. Dyes studied belong to the azo (color index, C.I. 15,510), methine (C.I. 48,013), indigo (C.I. 73,040), natural (C.I. 75,760) and arylmethane (C.I. 42,000) classes. Aliquots of the solutions treated at constant potential were analyzed and compared with control dye solutions. The final electrolysis solutions obtained by using different electrode materials: Pt, Ti and diamond presented different chromatograms. It was found that the novel (in this application) diamond electrode is efficient in studying the degradation of various dyes. Possible fragmentation and molecule moiety rearrangement are proposed as a result of the electrochemical treatment.
A study for the optimisation of the supercritical fluid extraction (SFE) of some aromatic amines (4-chloro-o-toluidine, 2-naphthylamine, 4-aminobiphenyl and benzidine) in finger-paints was conducted. The influence of different variables related to the technique on recoveries was investigated. The analytes were subsequently analysed by gas chromatography after SFE. The study allowed the estimation of four main factors (temperature, pressure, static time and volume of modifier) on recoveries by the use of a two-level factor design, where most significant parameters as well as second- and third-order interactions were identified. Other factors, such as type and volume of modifier and time of contact between the spiker solution and the sample prior to extraction, were also studied. The influence of matrix on extraction recovery was also evaluated by applying the method to different finger-paints, and recoveries were similar or even higher in some cases. The drying process of samples was also studied, while classical drying in an oven and microwaves were compared, with similar efficiencies in both methods. The method was validated by extracting the aromatic amines from some commercial finger-paints.
The use of modern electroanalytical techniques, namely differential pulse polarography, differential pulse voltammetry on hanging mercury drop electrode or carbon paste electrode, adsorptive stripping voltammetry and high performance liquid chromatography with electrochemical detection for the determination of trace amounts of carcinogenic N-nitroso compounds, azo compounds, heterocyclic compounds, nitrated polycyclic aromatic hydrocarbons and aromatic and heterocyclic amines is discussed. Scope and limitations of these methods are described and some practical applications based on their combination with liquid-liquid or solid phase extraction are given.
Azo dyes are widely used in formulations intended for children use. But their potential toxicity raised the need of an efficient and fast method of analysis. A study for the optimization of the extraction of some azo colorants used in toys was conducted. Several extraction methods for the selected analytes were evaluated and compared, i.e., supercritical fluid extraction (SFE), microwave-assisted extraction (MAE) and Soxhlet extraction. Poly(vinyl chloride) samples spiked with known quantities of the studied dyes were prepared. The influence of critical variables on analyte recoveries in SFE and MAE was investigated by using a full-level factorial design, where most significant parameters as well as order interactions were studied in each case. The analytes were subsequently detected by high-performance liquid chromatography with UV detection. The three extraction techniques were compared in terms of reproducibility, selectivity and analyte recoveries. MAE showed higher recoveries (above 98%), except for the diazo dye (nearly 60%). Reproducibilities were generally good for the three methods (relative standard deviation lower than 2.0%).
Occupational exposure to arylamines in industrial settings was the first known cause of bladder cancer in humans. In the United States and many developed countries, these industrial dyes have been under strict government control for decades and are believed to contribute minimally to today's population burden of bladder cancer in the West. The two other recognized, and potentially substantial sources of human exposure to arylamines are cigarette smoking and use of hair dyes. This paper reviews the latest epidemiologic findings on the relationships between smoking, hair dye use and bladder cancer risk. Results support the notion that arylamines contained in cigarette smoke and permanent hair dyes are human carcinogens. Furthermore, women may experience higher bladder cancer risk than men from comparable arylamine exposure, possibly due in part to women's higher propensity for arylamine activation relative to men.
The carcinogenic risk of aromatic amines in humans was first discovered when a physician related the occurrence of urinary bladder cancer to the occupation of his patients. They were employed in the dyestuff industry, chronically exposed to large amounts of intermediate arylamines. Laboratory investigations disclosed that rats and mice administered specific azo dyes arylamines or derivatives developed cancer, primarily in the liver. Also, at that time, a possible pesticide, 2-aminofluorene, was tested for chronic toxicity, revealing that it rapidly induced cancers in several organs of rodents. This led to investigations on the mode of action of this class of chemicals, including their metabolic conversion. Biochemical activation to more reactive N-hydroxy compounds was found to occur, mostly in the liver, through what is now known as the cytochrome p450 enzyme systems, and also through prostaglandin synthetases. There were species differences. Guinea pigs were resistant to carcinogenesis because of the low titer of the necessary activating enzymes. In target tissues, a second essential reaction was necessary, namely acylation or sulfate ester formation. The reactive compounds produced display attributes of genotoxicity in appropriate test systems. Interest in this class of compounds increased when of Sugimura and colleagues discovered the formation of mutagens at the surface of cooked meat or fish, that were identified as heterocyclic amines (HCAs). These compounds undergo the same type of activation reactions, as do other arylamines. Epidemiological data suggest that meat eaters may have a higher risk of breast and colon cancer. HCAs induced cancer in rats in these organs and also in the prostate and the pancreas. In addition, there is some evidence that they affect the vascular system. The formation of HCAs during cooking can be decreased by natural and synthetic antioxidants, by tryptophan or proline, or by removing the essential creatine through brief microwave cooking prior to frying or broiling. The amounts of HCAs in cooked foods are small, but other components in diet such as omega-6-polyunsaturated oils have powerful promoting effects in target organs of HCAs. On the other hand, the action of HCAs may be decreased by foods containing antioxidants, such as vegetables, soy, and tea. Some constituents in foods also induce phase II enzymes that detoxify reactive HCA metabolites. Additional mechanisms involved decreased growth of neoplasms by intake of protective foods. Possibly, the carcinogenic effect of HCAs is accompanied by the presence of reactive oxygen species (ROS), which are also inhibited by antioxidants. World-wide, there have been many contributors to knowledge in this field. Adequate information may permit now to adjust lifestyle and lower the risk of human disease stemming from this entire class of aryl and HCA.
A study for the determination of the aromatic amines formed after reduction of the azo colorants mostly used in toys was conducted. Sodium dithionite was used in the reductive cleavage of the azo group for the dyes, and the released amines were subsequently analysed by high-performance liquid chromatography with UV detection. The influence of different variables related to the reduction process was investigated by the use of a full-level factorial design, where most significant parameters as well as order interactions were studied. Reduction profiles for each colorant were obtained by studying the changes in the amount of amine obtained with different dithionite/colorant ratios. The expected aromatic amines forming azo colorants were detected, and in the presence of a nitro group a further reduction was observed. The yield of the total reduction process was determined by using standard addition of different quantities of amines to the colorants.