A SERS and HPLC study of traditional dyes from native Chinese plants

Surface-enhanced Raman spectroscopy (SERS) is proposed as analytical method for the characterization of extracts from Chinese plants traditionally used both as medicines and as textile dyes. Spectroscopic results are supported by high-performance liquid chromatography (HPLC) analysis of the extracts. In particular the spectra of extracts obtained from Chinese mulberry (Cudrania tricuspidata), gromwell (Lithospermum erythrorhizon), Chinese rhubarb (Rheum palmatum), tangerine (Citrus reticulata) and Morinda plants are reported here for the first time. A correlation between the SER spectral pattern and the structure of the molecules responsible for color is proposed for each of the examined dyes.