Abstract
Oils and fats of high polyenoic acids were found to have low recovery when the TLC·FID method was used to determine the triglyceride composition. Results of the hydrogenation-oxidation and direct oxidation methods for pretreatment of oils and fats were compared.
1) Linoleate decreased to less than 20% by selective hydrogenation using a 2% Cu-Cr-Mn catalyst at an H2 pressure of 00.1kg/cm2, and an H2 flow rate 10ml/g. min for 12 hours at 220°C. There was no increase in the saturated fatty acid content.
2) Oxidation of hydrogenated oils gave multiple peaks on the TLC·FID chromatogram and triglyceride recovery was more quantitative than the oxidation of unhydrogenated oils. However, the calculated composition of triglyceride from the analytical data of the hydrogenated and unhydrogenated oils was almost same.
3) The triglyceride composition of corn oil, rapeseed oil and the like were determined by the TLC·FID method with the oxidation of both oils.
