Comparative studies of oxidative stability of linseed oil

The oxidative stability of linseed oil was studied using classical method based on determination of peroxide value (PV), the Rancimat method based on conductometric measurements and thermoanalytical methods, i.e. the differential scanning calorimetry (DSC) and thermogravimetry (TG) in oxygen atmosphere. The onset temperatures Tonset,DSC and Tonset,TG were determined from dynamical DSC and TG curves, respectively. From isothermal DSC curves times tonset were determined. The effect of two antioxidants was also studied. An antioxidant blend containing α-tocopherol, ascorbyl palmitate, citric acid, ascorbic acid, and ethoxylated ethylene glycol proved more effective than butylated hydroxy anisole for protection of linseed oil against process, in good agreement with results obtained by the classical titration and the Rancimat methods.