Abstract
The effects of tri-n-octylamine (TOA) on the oxidative decomposition and dimerization of γ-and δ-tocopherol (Toc) during the thermal oxidation of trilinolein (Tri-Li) containing a small amount of tri-n-butylphosphate (TBP) was investigated.
After Toc (5%) and TBP (0.1%) were dissolved in Tri-Li and an aliquot of TOA was added to the solution, the solution was oxidized with air at 180°C for a fixed period of time. The determination of the concentration of Tocs and their dimers was carried out by HPLC.
The stability of Tocs increased by the addition of TBP in Tri-Li, while TOA had no influence on the stability. (Fig.-1) When TOA was added to Tri-Li containing TBP at a concentration of 0.1%, the stability increased (Figs.-2 and 4), indicating the phosphate ester and amine to act synergistically to suppress the thermal oxidation of Tocs in Tri-Li. On the other hand, small influences due to TOA and TBP appeared on the formation of Toc's dimers. (Fig.-3 and 5)
