Analysis of dye extracted from Phellodendron bark and its identification in archaeological textiles

Methanol extractions of 20 archaeological textiles excavated from burial sites in Korea were examined in comparison to standard natural dyes, freshly dyed silk, and naturally-aged dyed silks for the purpose of identifying archaeological textiles dyed with yellow dye from the Phellodendron bark. Phellodendron bark dye was identified by the presence of both berberine and palmatine using the retention times of HPLC-DAD chromatograms and mass spectral data generated from the electrospray ionization (ESI) source. Extracted ion chromatograms (EIC) were used to quantify the concentration of berberine and palmatine in each sample. The results indicated that three of the 20 archaeological textile samples were dyed with Phellodendron bark based on the significant amount of berberine and palmatine detected in these samples, while twelve samples were determined not to have been dyed with natural dyes from Phellodendron bark. Identification of dye in these textiles would allow for appropriate conservation procedures to avoid further dye loss.