Characterisation of Colourant Extracted from Almond Leaves

Abstract

This research reports on the extraction of colourant from the almond leaves, Terminalia catappa using ethanol, methanol and water as solvents .This study indicates that these dye compounds can be selectively extracted with solvents such as Distilled Water, Ethanol and Methanol. Methanol was found to be the most suitable solvent for the extraction of dye compound from Terminalia cattapa leaves. It reveals the presence of chromophores of dye compounds in the leaf. This study also reveals the presence of the hybridized ketone groups, Quinone as the central group in the dye compound extracted. The presence of the aromatic groups, derivatives of benzene and naphthalene were also demonstrated. Other chromophoric groups identified by this study are N-H, CH₃, O-H, C=O, =C–NH and O-H polymeric stretch. The critical conjugated groups present in the extract include derivatives of Ketone, Quinone, an Aromatic secondary amine N-H, C-C of the benzene ring. Others include C-O Alkyl substituted ether, O-H polymeric stretch, C-N and C-O-C cyclic ether ring. The presence of the derivatives of Quinone as indicated by the Infra-Red spectra and the maximum absorbance at the Violet, Blue and Green wavelength ranges suggest a possible presence of a mixture of dye(s) with a central Quinone ring; hence, a possible presence of an anthraquinone, naphthaquinone and/or indigoid dye.