The chemical profile of Rubia tinctorum in wool dyeing and a novel fibre extraction method for compositional analysis

This report describes the understanding of natural dyes and the work necessary for
analysis of historical textiles.
Chapter 1 provides a general introduction into the background of historical dyeing,
the methods used to extract these natural dye compounds used and how synthetic
dyes overtook natural dyes in the commercial world of dyeing.
Chapter 2 introduces and discusses the research undertaken with one particular
natural dyeing plant, Rubia tinctorum (common madder). Dyeing studies were all
performed on wool, and explore the dyeing properties of the madder plant. Dyeing
studies with pre-mordanting and post-mordanting were undertaken.
Chapter 3 explores the extraction of natural dyes from Rubia tinctorum and their
identification. Extraction and analysis studies were conducted to obtain the ideal
method for acquiring glycosidic anthraquinone dye molecules that could be used in
the dyeing process.
Chapter 4 focuses on identifying new methods to successfully remove glycosidic
anthraquinone dye compounds from wool fibres dyed with Rubia tinctorum, whilst
keeping their chemical structure intact. Further work in this chapter is undertaken to
analyse glycosidic anthraquinone dye compounds successfully removed from photodegraded
wool fibres and the comparison with current literature techniques used for
historical sample analysis.