How many grams of crude plant extract is needed to be dissolved in 12 X 15 cm of filter paper?
This very much depends on what types of materials you plan to impregnate into the paper, and also what type of paper it is. I would suggest to extract the plant materials with some very polar solvents. If you want to use the impregnated paper for a bioassay, then the more concentrated paper may have some inhibition. Are you dealing volatile compounds, or non-volatiles?
Hi. Try contacting Vector Control Research Unit, Universiti Sains Malaysia. They have been preparing papers impregnated with insecticides for WHO.
Dear Adibah,
maybe I am late, but it depends on the extraction medium /water, ethanol, chloroform, acetone....../ and stability given by chemical composition of the extract components. If your extract consists of phenolics and tannins they may undergo oxidation, if it contains mono- and sesquiterpenes the contents of crude extract in the paper might slightly get reduced with the time of storing /due to their evaporation/.
In general, when constituents of the extract are stabile, you may prepare saturated solution of crude extract and immerse the dry weighted filter paper into it. After short time take of the paper and dry it in a digestorium in horizontal position at ambient temperature. If saturated solution of the extract was water free and solvent was nonpolar, it is possible to determine amount of dry extract present in the impregnated filter paper simply as a difference between weight of dry impregnated paper and dry paper prior to impregnation.
The final drying can be performed in a dessicator over anhydrous CaCl2, 99% H2SO4, P2O5 and like...
R.S.
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