[blueberry58]

I had to extract free fatty acids an unsaponifiable fraction from bovine liver. Chloroform and methanol are the most used solvents but I must avoid them. Which are the best solvents in this case?

Thank you

[Arkcon]

I can't think of better ones for the task.  Why must you avoid them?  If methanol is too dangerous, you're kinda out of luck with regards to "safe" solvent.  You won't find many things "safer" that are still solvents.  With some specific information about which lipids you need (no, unsaponifiable isn't specific enough,) maybe something can be tailored to your application.  I'd like to guess if you saponified the fats, they'd wash away as soap in water, but its likely the saponified fats are still too insoluble, and what will you do with the rest of the liver -- connective tissue, proteins, etc.?