ANALYTICAL POTENTIALS OF DYE EXTRACTS FROM ASPILIA AFRICANA (ORAMEJULA) FLOWERS

Sequel to the increasing interest in the use of organic dyes and pigments because of safety, cost, and environmental considerations, the analytical potentials of ethanol, cold and hot water extracts of the flowers of Aspilia Africana was evaluated. The present study was part of a group of studies designed to evaluate the flower extracts of some readily available common plants to assess their analytical and industrial potentials. The flowers of Aspilia Africana was collected, dried, ground and dye extracts obtained by solvent extraction using ethanol, cold and hot water. 3 drops of the dye extract were dropped in 10ml of 0.1M H2SO4. This was titrated against 0.1M NaOH until the colour changed from light lemon green to light orange for ethanol extract of Aspilia Africana while the cold water and hot water extract gave the same colour changes at end point from light orange to light lemon green. The titration was repeated using standard indicators such as phenolphthalein, methyl orange, bromothymol blue and methyl red for weak acid/ strong base, strong acid/ strong base, strong acid /weak base and weak acid /weak base. The same acid and base of same strength were assessed using potentiometric titration. These results indicated that flower extracts of this plant can be used as acid-base indicator in all titration. The pH of these indicators was also determined. The rationale behind using these natural indicators in preference to synthetic indicators is its easy availability, biodegradability, more compatibility with the environment, inertness, ease of preparation and cost effectiveness.