Hello, I have a question about extraction process, I made distillation of rapeseed using petroleum ether; once finished I took some measurements of the extract's final mass directly from the round flask, no problem until then, but then I transferred the contents of the flask to a beaker and measured again; for some reason the mass was about 18 g less than before.
I'm guessing this has something to do with evaporation of the solvent after a few minutes, but is it really that quickly or what other sort of changes may happened?