High performance liquid chromatography of anthraquinones: analysis of plant and insect extracts and dyed textiles

TLDR

The method has been applied to extracts of plant roots and insects that historically served as sources of red dyestuffs for textile dyeing. High‑performance liquid chromatography in methanol–water–formic acid on a reversed‑phase column, with retention time, standard‑addition, and UV‑visible spectroscopy for identification, was used to quantify anthraquinones after acid hydrolysis of 0.2–2.0 mg of textile fibre. Its high sensitivity allows detection of minor constituents such as kermesic acid in cochineal.

Abstract

Separation and quantitative determination of anthraquinones is achieved by high performance liquid chromatography in mixtures of methanol, water and formic acid on a reversed-phase stationary phase. The products are identified by retention time and, more accurately, by standard additions and UV-visible spectroscopy. This methodology has been applied to extracts of plant roots and insects, commonly used in earlier times as the source of red dyestuffs for dyeing textiles. Quantitative evaluation of the anthraquinone derivatives present in ancient red dyes was earned out after acid hydrolysis of 0·2 to 2·0mg of textile fibre. Due to the great sensitivity of the method, important minor constituents, such as kermesic acid in cochineal, can be detected.