I wish to find out if there is a standard method (EN, ASTM etc) for determination of Campesterol, Stigmasterol and β-sitosterol in vegetable oils. This is very important to the biodiesel industry since at least β-sitosterol is known for the creation of steryl glucosides under base conditions,

Or, if there is a common method, but not standardized, I would be happy to have its name too.