High‐Performance Liquid Chromatographic Analysis of an Ancient Tyrian Purple Dyeing Vat from Israel

Abstract

AbstractThe high‐performance liquid chromatographic technique is utilized to analyze the dye components of crude “Tyrian Purple” residues obtained from modern Murex (Trunculariopsis) trunculus sea snails and from an archaeological source. This is the first time that this technique has been used to analyze these raw pigments. Previously, chromatographic analyses of cloth stains and textile vat dyeings produced from contemporary snails were published. The modern purple pigment analyzed in this study was produced from excised hypobranchial glands of trunculus snails, and the archaeological purple residue investigated was found on the interior of a potsherd from Tel Kabri, Israel. The two pigments studied showed nearly identical chromatographic fingerprints: The pigments consisted of the same four indigoid components and with matching compositions. The dyes found were indigotin, monobromoindigotin, dibromoindigotin, and a fourth colorant that may be dibromoindirubin. The following conclusions can be made regarding the archaeological sample: (1) the ancient potsherd bearing the purple pigment was from an ancient dyeing vat; (2) the biological provenance of the archaeological dyestuff was most probably Murex trunculus mollusks; and (3) the Mediterranean snails used for the vat were likely collected at or near the Akhziv beach area in Israel. This study indicates that a biological and geographical chromatographic mapping of the dye components of porphyra snails can be developed to assist in provenance determinations of archaeological purple pigments.