Earl S. Huyser

The role of lipid, free radical initiator, and oxygen on the kinetics of lipid peroxidation

Abstract The relationship between the concentration of unsaturated lipid, free radical initiator, and oxygen concentration on the kinetics of lipid peroxidation was determined. The rate of lipid peroxidation was studied with the thiobarbituric acid (TBA), diene conjugation (DC), and ferrithiocyanate (Fe-SCN) methods. The rate of peroxidation was half-order with respect to unsaturated lipid, initiator, and oxygen. The half-order relationship could be expressed as: rate = ( fk 1 k 2 k 3 k 6 1 2 ( azobisisobutyronitrile ) 1 2 ( RH 1 2 ( O 2 ) 1 2 . The half-order relationship was found with linoleic (18:2), linolenic (18:3), and arachidonic (20:4) acids. A linear relationship existed between the logarithm of unsaturation and the rate of peroxidation. No peroxidation of linolenic acid was indicated when the DC method was employed, but was when the TBA and Fe-SCN methods were used.