MODIFIED METHOD FOR THE DETERMINATION OF UNSAPONIFIABLE MATTER IN OILS AND FATS

An inversion of the existing methods for the determination of unsaponi fiable matter in oils and fats is proposed. The modified procedure con sists in saponifying a 2-2.5 g sample of oil or fat with 2 mol l(-1) e thanolic potassium hydroxide solution, dissolving the resultant mixtur e in 50 ml of pure cyclohexane, removing the soap by addition of 25 ml of water containing 0.5 g of sodium hydrogencarbonate and extracting the separated soap layer with 25 ml of cyclohexane. The combined cyclo hexane layers are washed twice with 25 ml portions of 50% aqueous etha nol, cyclohexane is evaporated and the residue is dried in vacuo at 80 degrees C. Results obtained with the above procedure in the determina tion of the unsaponifiable matter in four different vegetable oils wer e in agreement with those given by the IUPAC standard hexane method II .D.5 with economy ofsolvents and operational time.