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Banned aromatic amines due to their acute toxicity in human and animals hold key importance. Certain azo dyes have the tendency to release these banned amine intermediates upon cleavage of azo bond(s), even when present in a dyed materials. The tendency of four selected azo dyes (acid red 1, direct red 28, direct blue 15 and direct red 7) to release harmful aromatic amines is analysed by the standard test methods for colorants, dyed leathers and textiles (cotton, linen, wool, nylon). The basic steps of these tests methods are similar comprising of reduction, extraction and detection by instrumental techniques. The standard method for colorants was modified for UV-visible spectroscopy in initial exploration so that a quick inference could be generated. Methods based on sophisticated techniques (e.g., GC-MS and HPLC-DAD) were used in advanced steps. Conventional reduction methods were modified using ultrasound (UAR) and microwave assisted reductions (MAR) as greener techniques. UAR experiments were additionally extended with variations of temperature and exposure time. Direct dyes were applied onto leather, wool, linen, and cotton whereas the acid dye was applied to leather, wool, and nylon (due to substantivity). All dyed samples were profiled for banned aromatic amines through GC-MS. Only DR-28 released a listed banned amine, biphenyl-4,4''-diamine in significant quantities and was selected for UAR and MAR trials. Results of UAR for 10 min caused reduction equivalent to standard methods in case of leather and wool. Comparable results were also obtained in case of MAR reduction. Pertinent results were also confirmed using HPLC-DAD. The most economical methods were MAR with an energy saving ranging between 92 and 95% and a time saving of 70 to 80% (42-48 min) as compared to the standard methods. UAR methods provided energy and time savings of 80-85% and 22-42% (13-25 min) respectively. Greener approaches were found best for matrices in following order; leather > wool > cotton. Additionally a useful scheme was suggested for the non-destructive and greener analysis of ten lab-synthesized azo dyes using Fourier transform infrared spectroscopy with little or no sample preparation. The key region (azo band) appeared between 1504 and 1555 cm-1.
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