Determination of peroxide value in vegetable oils by an organic-phase enzyme electrode

An organic-phase biosensor is used for measuring the peroxide value in vegetable oils. Rapid flow injection monitoring of the peroxide value is accomplished by injecting the untreated oil sample directly into a chloroform carrier solution which transports it to the downstream horseradish-peroxidase (HRP) based flow detector. The Eastman AQ polymer is used for entrapping the HRP onto the detector surface. The new scheme offers convenient monitoring of low level peroxide values and high selectivity (accrued from the biospecificity of HRP towards peroxide species and from the low operating potential). The biosensor results are consistent with those obtained by the official iodometric method. Such development should facilitate quality control testing of oil products.