engleski

PROCESS OF OBTAINING AND ANALYSES OF PURPLE DYE FROM MUREX TRUNCULUS

Tekhelet (biblical Hyacinth Purple) was manufactured in antiquity from banded dye-murex (Phyllonotus trunculus). It had a violet colour, and chemically its composition is a natural mixture of dyestuffs, blue indigotin and purple 6, 6`-Dibromoindigotin (DBI). When the hypobranchial gland contents of male and female banded dye-murex are mixed before all precursors present have formed DBI and indigo-blue, 6-bromoIndIgotIn (MBI) may be formed. The content of the indigo-blue constituent is thereby lowered. If sufficient MBI is thus produced, the dyeing will not be violet but purple. This explains why banded murex may vary in hue from reddish to bluish purple. Entrepreneur Antonio Ficović from Ston, Dubrovnik started an additional economic activity through breeding Murex marine shellfish. Nature of mollusks is parasitical as it feeds on dead seashells, mainly mussels and other species found at the bottom of the Croatian sea floor. As the species breeds twice a year, it is possible to obtain a relatively large number of units, some of which can grow up to 50 cm in length, while the average remains at around 15 cm. This paper describes the process of obtaining purple dye from hypobranchial glands. A detailed chemical analysis in the aim of controlling the quality of the powder presumed to be dye, was done at the Department of Textile Chemistry and Ecology, Faculty of Textile Technology. A serious of chemical analyses, UV/VIS spectrophotometry and FTIR – ATR confirmed a mixture of indigo components present in the investigated sample with a more significant part of 6, 6' – Dibromoindigotin (DBI) characteristic for purple colour.

Murex; purple; indigo; FTIR – ATR; UV/VIS.

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