Fiber-Safe Extraction of Red Mordant Dyes from Hair Fibers

In 1995, researchers Erica J. Tiedemann and Yiqi Yang developed a less destructive method for extracting red mordant dyes from wool fibers, using a solution of 0.1% EDTA and DMF. This method was compared to the traditional strong acid extraction and proved to be less harmful to the fibers, allowing for further analysis. Spectrophotometry confirmed the successful identification of the dyes extracted from various dyestuffs and pre-Columbian cameloid fibers. Tensile strength tests on cochineal-dyed fabric, which included 40 yarns with 20 as controls, indicated a retention of tenacity despite some loss of strength. The study concluded that the EDTA/DMF method is a viable nondestructive alternative for dye extraction, potentially applicable to other analytical techniques like TLC or HPLC, although these applications were not tested in the study.