It seems to me that the solid residue left behind in a rotary evaporator is always stuck firmly to the sides of the glass. Is scraping the only option out there? What's an easy and efficient way to collect the sample without risking breaking the glass, or without losing significant yield?
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Add a minimal amount of volatile solvent to the flask. Warm the bottom to volatilize it and keep the upper surface cool to condense the solvent and let it run down the walls of the flask. This will put the solution on the bottom where it can be removed for collection.