IDENTIFICATION BY RP-HPLC-DAD OF NATURAL DYESTUFFS FROM LAKE PIGMENTS PREPARED WITH A MIXTURE OF WELD AND DYER'S OAK DYE PLANTS

Abstract

The lake pigments by means of the weld (Reseda luteola) and dyer's oak (Quercus infectoria) dye plants were prepared by using KAl(SO4)2 · 12H2O (alum), FeSO4 · 7H2O and SnCl2 · 2H2O mordants. A reversed-phase high performance liquid chromatography (RP-HPLC) with diode array detection (DAD) method was utilized for the identification of dyestuffs present in the lake pigments. The dyestuff extractions from the pigments were carried out with a solution mixture of 37% HCl:MeOH:H2O (2:1:1, v/v/v). The performed method is able to analyze and detect natural dyestuffs such as luteolin, apigenin, gallic acid, and ellagic acid present in the lake pigments.