Asuming I've combined a few substances extracted from plants, in order to make a powder, how do I extract them back from the powder in order to check if they are in proper proportions in the mixture?
I don't know the specific of your substances, but maybe you don't have to separate your powder. Try to make an IR (or DTA) analysis every separate substance and then compare the particular spectras with the spectrum of your mixture. Maybe it will be possible to do a kind of quantitative analysis.