Ext ration method for pine oil content in a commercial cleaner?

Can anyone suggest a method for the determination of 85% pine oil in a commercial cleaner? I originally put a 500 gram sample on a rotoevaporater only to retrive erroneous results ,which I belived were due to the tallow present in the solution. Therefore, I think if I can extract the tallow from the solution prior to evaporation, I can achive a correct representation of the turpine in question. But I am afraid that finding a method is a bit dauting.Please any ideas?? where I can locate a usable method?? thanks to all who answer!