Application of drift spectroscopy and chemometrics to the discrimination of dye mixtures extracted from fibres from worn clothing

Abstract

Diffuse reflectance infrared Fourier transform spectra were collected from microscopic amounts of dye mixtures (200–400 ng) extracted from small yarn and filament samples obtained from selected areas of a number of worn polyester or polyester-blend garments. Pre-treated data matrices were interpreted using several chemometric methods, viz., principal component analysis and soft independent modelling of class analogies. These analyses showed that it is possible to discriminate and match the diffuse reflectance infrared Fourier transform spectra of the dye extracts according to (i) the dye mixture and hence the source garment, (ii) the sampling area on the garment and the amount of soiling, and (iii) the degree of normal processing such as washing of a garment.