CYCLIC VOLTAMMETRY OF LIPOPHILIC COMPOUNDS IN OIL - DIRECT DETERMINATION OF LIPID PEROXIDE WITH A CARBON PAST ELECTRODE

In preliminary experiments, we demonstrated that a cyclic voltammogram of a lipophilic compound can be conveniently obtained with the past e lectrode that was made from graphite powder and an oil in which the co mpound is dissolved. This finding was applied to the direct determinat ion of lipid peroxides. Oxygenation of lipids at 120 degrees C was fol lowed by the cathodic current created by the reduction of the peroxide s. The validity of the method was investigated by comparison with conv entional methods (peroxide value, thiobarbituric acid, and weight gain ). The amount of peroxides in an oil and its cathodic current show a l inear relation in the initial stages of peroxidation (ca. 12 h). This electrochemical method was applied successfully to the evaluation of t he antioxidant activity of butylated hydroxytoluene in linseed oil.