Screening Anti-Oxidant Activity at Oil Microdroplet Triple Phase Boundary Electrodes

Highly non-polar/non-conducting media such as natural or synthetic oils cannot be analysed by conventional single phase solution voltammetry, but it is shown here that, when they are deposited onto suitable basal plane pyrolytic graphite electrode surfaces, the triple phase boundary reaction zone in liquid | liquid two-phase systems in contact to a graphite electrode can be exploited for the electrochemical determination of the content and activity of anti-oxidants such as Irganox L-135 and L-57 in fuel (methyl-laurate) and in oil (commercially available API Group III base oil) media.