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ABSTRACT
An increased environmental awareness of health hazards caused by synthetic dyes has led to revival of natural dyes. Dyes obtained from natural sources have emerged as important substitutes for synthetic dyes. Color-yielding plants such as butterfly pea flowers have been used to study color extraction and can be used as dyeing material for coloring industry. Analytical studies, such as UV-VIS spectrophotometer analysis and dye concentration analysis, are performed on extracted dye using flower petals. In this study, aqueous extractions of dye from flowers were carried out in the following conditions to obtain optimization characterization: time of extraction (30-180 minutes), temperature (60-900C), amount of flowers (0.1 -2gm) and pH (2-10). It was observed that dye concentration increases gradually at higher temperature and for longer time.
Keywords: Butterfly Pea, Blue Dye, Aqueous Extraction, Analytical Method, Spectrophotometer Analysis
1. Introduction
Natural colors have been part and parcel of our life since ancient times. The art of dyeing with natural dyes was common in India. In the 7th century, India had a virtual monopoly in dyed, painted and printed textiles with natural colour (Parkes, 2002). The Indian dye was famous for its variety of shades with natural mordents. Until the invention of widely available and cheaper synthetic dye "Perkin Mauve" in 1856 (Parkes, 2002), natural sources like stem, bark, leaves, roots and flowers were used to obtain colors for dyeing clothes. Synthetic dyes are extensively used in textile industries for dyeing nylon, wool, silk, leather and cotton (Hameed & El-Khaiary, 2008; Cha Doerge & Cerniglia, 2001; Srivastava, Sinha & Roy, 2004), and they are also used as food coloring agents, food additive and medical disinfectants and anthelminthics (Srivastava, Sinha & Roy, 2004). However, some synthetic dyes (Kamel et al., 2005) are harmful due to their negative ecotoxicological effects and associated hazards, such as skin diseases, lungs problems and environmental problems. Therefore, interest in natural dyes has increased considerably on account of their high compatibility with the environment, relatively low toxicity and allergic effects, as well as availability of various natural coloring sources, such as plants, insects, minerals and fungi (Patel., Agarwal & Patel, 2003). It is worthwhile to identify various resources for extraction of natural dyes as they significantly minimize the amount of toxic effluent from...