| Abstract
| - Analysis of dyes extracted from textiles of historicalinterest can give valuable information as to where, when,and how the textiles were made. The most widely usedmethod for extraction of colorants involves heating withHCl, which frequently decomposes glycosidic dye components to their parent aglycons, with consequent loss ofinformation about the source of the dye. This is particularly true for flavonoid dyes, many of which are glycosides.We have developed or improved upon two mild textileextraction methods that use ethylenediaminetetraaceticacid (EDTA) and formic acid and are efficient in extractingdyes, but preserve glycosidic linkages. The relative efficiencies of the HCl, EDTA, and formic acid extractionmethods are compared by analyzing extracts of dyedsamples of silk using HPLC coupled with diode array andmass spectrometric detection. HPLC profiles of EDTA orformic acid extracts of silk dyed, for example, with pagodatree buds and onionskins are clearly distinguishable asto the plant material used, whereas profiles of HCl extractsare not. Thus, extraction of textiles with EDTA or formicacid reagents can yield significantly more informationabout the original dyestuff than can extraction with astrong acid.
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