USEFUL PROCEDURES FOR THE DETERMINATION OF COMPLEX FATTY ACID COMPOSITION. OCCURRENCE OF TRANS-5-HEXADECENOIC AND TRANS-5,CIS-9-OCTADECADIENOIC ACIDS IN THE OIL FROM THALICTRUM VENULOSUM

Abstract

The complete fatty acid composition of fats and oils can be readily determined by use of silicic acid – silver nitrate column chromatography in conjunction with gas–liquid chromatography, permanganate–periodate oxidation, hydrazine reduction, and infrared analysis. These techniques were used to demonstrate the occurrence of trans-5-hexadecenoic (2.6%) and trans-5,cis-9-octadecadienoic (4.6%) acids in the seed oil of Thalictrum venulosum. The oil contains two predominant and one minor system of fatty acids: (i) trans-5-hexadecenoic, trans-5-octadecenoic, trans-5,cis-9-octadecadienoic, trans-5,cis-9,cis-12-octadecatrienoic; (ii) cis-9-hexadecenoic, cis-9-octadecenoic, cis-9,cis-12-octadecadienoic, cis-9,cis-12,cis-15-octadecatrienoic; and (iii) cis-5-hexadecenoic, cis-5-octadecenoic, cis-5-eicosenoic.