CTinHS Lecture 3/2022: Chromatographic analyses of molluskan purple pigments
The CTinHS lectures are part of HS Academy: a collaborative initiative between IPERION HS (www.iperionhs.eu) and E-RIHS (www.e-rihs.eu). The two European projects integrate facilities of recognized excellence in Heritage Science, offering access to a wide range of high-level scientific instruments, methodologies, data, tools and training opportunities for advancing knowledge and innovation in the field.
The third lecture of the “Current Topics in Heritage Science” series will be delivered by Prof. Zvi C. Koren on Thursday, November 17th, at 3 pm (Rome time).
The most regal of all textile dyeings performed in antiquity was undoubtedly from the purple pigment produced from the colorless precursors contained in the hypobranchial glands of certain species of the Muricidae family of mollusks – known as Murex sea snails. This pigment was first used as a paint pigment for decorating walls in the Aegean area from nearly four millennia ago. Later, in about the middle of the 4th millennium, it is probable that the Levantine Phoenicians discovered the method by which these pigments could be dissolved and transformed into a dye for the dyeing of textiles for sovereigns, high-ranking military personnel, as well as High Priests. Hence, dyeings with this pigment are sometimes referred to as “Royal Purple” or “Tyrian Purple”, after Tyre, one of the important cities of Phoenicia.
The noteworthy classes of snails from the Mediterranean region are Hexaplex trunculus (also known as Murex trunculus), Bolinus brandaris (= Murex brandaris), and Stramonita haemastoma (= Purpura haemastoma). There are other sea snail species from other parts of the world’s seas that can also produce a purple pigment. The common dye component of all purple-producing sea snails is the reddish-purple dibromoindigo (DBI). This is also the nearly sole component in all sea snails, except for H. trunculus, which can have as many as about 10 different colorants, most notably violet monobromoindigo (MBI), and blue indigo (IND).
There are many questions regarding the ancient purple pigment and dye, such as what is the malacological source of these archaeological pigments and dyeings, what was the ancient method by which these dyeings were performed, and more. Case studies of HPLC chromatographic analyses of archaeological samples dating from three millennia ago can answer these questions. So, stay tuned for an exciting and colorful ride into the past.
November 17th, 2022 at 3 pm (Rome time zone)
You will learn
- How to study dyes in archaeological textiles using chromatographic techniques
- History and composition of natural purple pigments and dyes
Key topics we’ll cover
- Natural dyes
- Purple dyes
- Archaeological textiles
45 minutes (30 minutes + 15 minutes Q&A)
Prof. Zvi Koren is Professor Emeritus from the Department of Chemical Engineering at the Shenkar College of Engineering, Design and Art in Israel. He has been the Director of The Edelstein Center for the Analysis of Ancient Artifacts at Shenkar since the Center’s inception in 1991. Prior to that, Zvi was the Head of the Department of Chemistry at The Cooper Union in New York. He received his B.S. degree in chemistry and mathematics from Brooklyn College and his Ph.D. in physical chemistry from the City University of New York.