 Contributors F. I. H. Mohideen S. K. G. M. A. Jayawardana N. N. Galagedara T. M. Kumara Y. E. Herath P. T. Liyanage

 Coloring agent  Imparts color to other material  Contains chromophores  Chromophores absorb some wavelengths of light preferentially

 Have less toxic effect on humans and environment  Pharmacological effects  Obtained from renewable sources  No disposal problems  Do not stain the adjacent fabrics in the washing process

 Dyes used at ancient times to colour robes for paintings & fabric  Abundance of unutilized plants waste plants

 Each student was given a task. Student 1&2: extraction of pigments from different plant materials Student 3: preparation of the crudes Student 4: solubility test for the crudes Student 5&6: stability tests for prepared dyes

 Cost effective extraction method :- Boiling  Extraction process higher yield of crude :- Pathangi wood Mahogany saw dust

 Crude preparation Alum :- speed up the precipitation process  Solubility test best solvent :- 0.1M NaOH  Stability test temperature Pathangi -temperature stable Mahogany - temperature sensitive pH -pH unstable light -sensitive  Antifungal activity -towards Curvularia and Aspergillus

 work during free times  sharing of data  collective work in report writing  Photographic skills

 We express our special gratitude to Dr. Sudheera Ranwala, Dr. P. S. Saputhanthri, Department of Plant Sciences, University of Colombo.  Academic and Non Academic staff, Department of Plant Sciences