Bright new colours: the history and analysis of fluorescein, eosin, erythrosine, rhodamine and some of their derivatives

This paper discusses the history, chemical constitution, production, dyeing processes and properties of the hydroxyphthaleins. Important dyes of this dye class are fluorescein, the eosins, phloxines, erythrosines, rose bengals and rhodamines. These dyes were used for textile dyeing and as painting materials. A new HPLC–PDA method especially developed for the analysis of acid dyes was applicable for the hydroxyphthaleins, which are considered acid dyes, with the exception of the rhodamines. The last part deals with their use as artists’ pigments focusing on geranium lake (eosin) that was applied in Vincent van Gogh’s oeuvre.