Identification of Onion Dye Chromophores in the Dye Bath and Dyed Wool by HPLC-DAD: An Educational Approach

• Autores: Cristina Barrocas Dias, Marco Miranda, Ana Manhita, António Candeias, Teresa Ferreira, Dora Teixeira
• Localización: Journal of chemical education, ISSN 0021-9584, Vol. 90, Nº 11, 2013, págs. 1498-1500
• Idioma: inglés
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• Resumen

  • Onion skins (Allium cepa L.) and hydrated potassium aluminum sulfate were used to dye wool samples. The main chromophores associated with this natural dye source, quercetin and quercetin-4′-O-glucoside, were identified in the dye bath and in wool extracts by high-pressure liquid chromatography (HPLC) equipped with a diode array detector (DAD) with the help of standards. Two procedures were used to extract dye molecules from dyed wool prior to HPLC-DAD qualitative analysis and the analytical methodology used was discussed in terms of the analysis of historical textile pieces dyed with natural sources.