Synthetic antioxidants determination in lard and vegetable oils by the use of voltammetric methods on disk ultramicroelectrodes

Abstract Voltammetry on ultramicroelectrodes was used to determine antioxidants tert-butylhydroxyanisole (BHA), tert-butylhydroxytoluene (BHT) and propyl gallate (PG) in vegetable oils or lard. The present work demonstrates the advantages of using not only the conventional three electrode configuration but also the non-conventional two electrode configuration cell system, with respect to the determination of antioxidants. Different ways of performing the determinations are compared either through step by step extractive procedures or through direct measurements using standard addition. Detection limits in the range of (0.20–1.25)×10−5 mol dm−3, (1.00–1.25)×10−5 mol dm−3 and (0.60–1.00)×10−5 mol were obtained for BHA and BHT in vegatable oil and PG in lard determinations, respectively, depending upon the medium composition. Relative standard deviations for antioxidants concentration were about 6–7% for most of media studied and can be compared with those reported for HPLC from collaborative studies, i.e. 4.54, 6.61 and 3.18% for BHT, BHA and PG, respectively.

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