Ultrasound‐assisted reduction of bis azo dye into aromatic amines on natural textile fibres: A greener approach

• DOI: 10.1111/cote.12592
• Publication Date: 2022-01-05T03:49:55Z
• Authors: Rajkumar Dewani; Munawwer Rasheed; Farman Ahmed; Muhammad Zubair Asim; Mansoor Shaikh; Muhammad Kashif P...
• Keywords: 01 natural sciences; 0104 chemical sciences

AbstractThe current study elaborates on the capabilities of ultrasonic waves in improving the conventional method for analysis of banned aromatic amines in dyed textile samples. Wool, linen and cotton were dyed according to their relative affinity with a selected benzidine‐based dye, CI Direct Red 28. The standard procedure, BS EN 14362‐1:2012, was used for testing dyed textile samples, with final estimation through gas chromatography‐mass spectrometry. The dyed samples, after reduction, released a significant quantity of benzidine (listed banned amine), hence were chosen for experiments with ultrasound‐assisted reduction (UAR). To explore the influence of ultrasound energy on the reduction of bis azo dye, the standard procedure for analysis of banned aromatic amines in textiles was modified incorporating minor changes. The reduction step in the altered methods was performed with ultrasonic aid in less time, while the rest of the method remained unmodified. The altered procedure was designated as “method 2”. Samples were quantified with gas chromatography‐mass spectrometry. The extent of the reduction was correlated with wetting characteristics of textile materials. The results from the standard test procedure were used for comparison with those obtained from UAR trials. The UAR method in the case of wool, assessed in terms of greenness, provided noticeable time and energy savings. A comparative account of the chosen matrices with respect to dye reduction is also presented.