Abstract:
Dyes from Pterocarpus osun Craib and Lawsonia inermis Linn. were extracted using ethanol and methanol respectively. The extracted dyes were subsequently purified using chromatographic methods. Purified pigments were characterized using Ultra-Violet Visible Spectrophotometer, Fourtier Transform Infrared Spectrophotometer and Lovibond Tintometer. The UV spectra of the dyes in petrol, kerosene and diesel showed presence of chromophores. The FTIR spectra of the dyes showed presence of phenolic O-H stretching and C=C of aromatic functional groups. The dye from Lawsonia inermis Linn. was remarkably stable in colouring petrol for a period of twenty-eight days but not in kerosene and diesel while the dye from Pterocarpus osun Craib was not stable. Thus, dye from Lawsonia inermis Linn. can be used as alternative source of colourant for petrol while the dye can not be used for the same purpose for kerosene and diesel due to their instability. The dye from Pterocarpus osun Craib cannot be used because of their instability. They are not remarkably active in colouring any of the petroleum products (petrol, kerosene and diesel).
