Liquid chromatography as analytical tool for the study of natural and early synthetic dyes in traditional Saxon textiles

Abstract

Confirmed since the 12-th century, the Saxon community in Transylvania developed over the years in a rigorous powerful society, with its own lifestyle, social, economic, cultural and artistic standards. Together with research in historic documents, this society is now revealed by material studies of 18-th to 20-th century objects in the Emil Sigerius collection, preserved in the ASTRA Museum, Sibiu. Embroideries made in Saxon households as well as representative Saxon coats manufactured in workshops and dated between 1892 and 1908 (years embroidered on objects) were studied in terms of dye analysis in order to understand if adoption of new materials goes together with the stylistic improvements. Dye analysis were performed by liquid chromatography with UV-Vis and mass spectrometric detection (LC-DAD-MS), nowadays the most appropriate technique for the characterization and identification of colour components in heritage textiles. MS/MS detection, in its tri-quadrupolar architecture, with the middle quadrupole used as collision cell, was used to achieve undoubted identification of each dye in a complex matrix. Construction of suitable spectral libraries through studies on standard dyes and dyed textiles definitely improved the ability to undoubtedly detect natural and early synthetic dyes. Identification of fuchsine (1856), methyl violet (1861), orange II (1876) brilliant green (1879), quinoline yellow (1881) and rhodamine B (1887) in textiles dated about 20 years after the dyes first synthesis prove that transition from natural to synthetic dyes in the Saxon community was very fast, especially in what textiles made in specialized workshops are concerned. The analytical technique used for the natural and early synthetic dyes characterisation and identification, and especially the triple quadrupole mass spectrometer with its possibility for tuning the selectivity through appropriately exploiting the functioning modes, as well as to increase sensitivity, confirms its ability in studies aiming in understanding textiles through dye analysis and promotes the use of advanced analytical techniques in heritage science applications.

Liquid chromatography as analytical tool for the study of natural and early synthetic dyes in traditional Saxon textiles

“…For the one remaining sample (2075_P6), it was estimated that Mexican cochineal was used for dyeing. This supposition is based on studies performed in the same research team * Although some dyes are present in more than one biological source, only those discussed in the present study are given in the table; [43], where large amounts of flavokermesic acid C-glycoside relative to carminic acid were observed in the Mexican cochineal dyed samples. Carminic acid-based-dyes were used on wool in a towel dated 1832, on silk in a handkerchief dated 1779, a head cover dated 1869 and a nineteenth century pillow cover.…”