So essentially I am writing a research paper on curcumin right now, and I am using soxhlet extraction with acetone as the solvent. After doing so I need to evaporate the solvent from the soxhlet mixture, before I can add the separating solvent that is used for column chromatography. However, there is this red substance(that is not a curcuminoid) that appears to be red and also immiscible and insoluble with and in the separating solvent. It is likely that it is the acetone that is used in the soxhlet extraction, correct me if I am wrong, but it is for some reason having a hard time being evaporated from the mixture. I performed rotovap with it, and it still remains really red. One time where we left the mixture out for a long time accidentally allowed it to solidify and properly dry up, allowing for separation by adding separating solvent and also decanting. Can someone please help or explain to me why there is the red stuff there? Is it because it is really tightly associated with the solute, and thus hard to evaporate? My chemistry knowledge is really basic, as I am still an IB student, thank you guys for your help.