High-performance liquid chromatographic determination of some anthraquinone and naphthoquinone dyes occurring in historical textiles

A reversed-phase HPLC method has been developed for identification and quantitation of nine natural quinone dyes and applied to historical textile fibres. A Purospher RP18e column was used with a convex gradient of methanol in a mobile phase of 0.1 M aqueous citrate buffer (pH 2.5) and spectrophotometric diode-array detection at 270 nm. For identification of alizarin, purpurin and xanthopurpurin, occurring together in the madder plant, an isocratic method was used with a methanol–0.2 M acetate buffer (pH 4.3) (75:25) as the mobile phase. After an acid extraction of textile fibres and the analysis of the extracts, alizarin and purpurin were identified and quantitated in three fibres.