Dear Sir. Concerning your issue about removal of slovent from nonpolar solvent extract through Lyophilization . You must not heat your sample in the rotavapor more than 37 or 40ºC, if you have temperature-sensitive compounds. As the rotavapor allows high vaccum, you can evaporate at a relatively high rate even at 35ºC. I think the following below links may help you in your analysis: