Chemical compositions of Stramonita haemastoma and Bolinus brandaris : New data relevant to cultural heritage studies

Abstract

Pigments (extracts) from Stramonita ( Thais ) haemastoma and Bolinus (Murex) brandaris molluscs, which were collected along the coastline of Tunisia and processed under sunlight, are analysed using High Performance Liquid Chromatography (HPLC) coupled to a Diode Array Detector (DAD). The most important result is that according to the measured areas of the HPLC peaks, the samples of both molluscan species are very rich in indigotin followed by 6‐bromoindigotin and 6,6′‐dibromoindigotin. Such HPLC results are frequently reported in the literature for Hexaplex ( Murex) trunculus pigments. Consequently, the findings of this study reveal that the characterisation of archaeological molluscan colorants, and in particular the identification of molluscan species employed in archaeological objects, is challenging. Finally, it is noted that indirubinoids are detected in both investigated molluscan species, albeit in substantially lower proportions than the indigoids.