Bunsen coefficient for oxygen in marine oils at various temperatures determined by an exponential dilution method with a polarographic oxygen electrode

A polarographic oxygen electrode has been applied to an exponential dilution method for the determination of the solubility of oxygen in oils. Results are compared with other chemical and physical methods for herring and olive oils and the same oils subjected to partial oxidation. The Bunsen coefficients for oxygen in nine marine oils have been determined by this procedure between 20 and 80 C, with a relative standard deviation of ±7% or less. The densities and viscosities of these oils have been measured for the same temperature range. In general, the Bunsen coefficient for oxygen in marine oils increases with an increase in temperature between 20 and 60 C, but then rapidly decreases between 60 and 80 C to a value lower than that for room temperature. It appears that autoxidation should not be the major cause of this effect, as the measurement rate was relatively rapid. Some tentative correlations between the solubility of oxygen in marine oils and the fatty acid composition, iodine value, density and viscosity are discussed briefly.