The Effect of Light Colour and Intensity on the Rate of Photosynthesis
This easy science project shows simple and efficient method of chlorophyll extraction from a plant.
This is only a demonstration of working method which can be refined and used for a full scale science project.
Plants contain many pigments in different proportions. For flowering plants it's mostly a combination of chlorophyll-A, chlorophyll-B, pheophytin and Carotenes. These pigments have shades of green, blue green, grayish, and yellow-orange. Their concentration is different for different species and also depends on the time of year. Also, these pigments have different solubility in different solvents.
Extracted pigments could be used in another project, such as chromatography.
Attention! This method involves usage of flammable, volatile and toxic substances. All work with solvents should be conducted on the open air or in actively ventilated room. Adult supervision recommended for this project!
Required Materials (in order of appearance): * Dark green leaves of any plant * Cup * Scissors * Water * Paper towel * Foil * Oven * Mortar and pestle * Glass test tubes with lids or small glass jars with tight lids. * Tea or coffee. (Optional)
You may try one of the following solvents: * Rubbing alcohol/ethanol * Isopropanol * Acetone * Hexan
All this solvents can be used for chlorophyll extraction. However they have different property called polarity. This property affects their efficiency as chlorophyll solvent.
For our tests we used isopropanol and hexan/benzin mixture.
Note: solvent mixtures can give better results in extraction of the full complex of plant pigment then individual solvent. You could study how good the different solvents and their mixtures for chlorophyll extraction are. (Good chemistry science fair project idea, by the way).
Another note: as a general rule solvents must be as chemically clean as possible. For example nail polish may not