Premium
Electrochemical determination of vitamin E in margarine, butter and palm oil
Author(s) -
Atuma Samuel S.
Publication year - 1975
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740260403
Subject(s) - unsaponifiable , chemistry , saponification , ethanol , solubility , benzene , chromatography , extraction (chemistry) , vitamin e , raw material , tocopherol , nuclear chemistry , organic chemistry , antioxidant
A simple, rapid and reproducible method is described for the analysis of tocopherols in margarine, butter and palm oil. The method involves saponification, extraction of the unsaponifiable material and direct voltammetric determination. No separation technique is necessary. Two indicator electrodes, glassy carbon (GCE) and carbon paste (CPE), have been employed in this work, GCE in ethanol‐benzene (2:1) medium and CPE in 75% ethanol. The CPE gives over ten times as much current as the GCE for a given tocopherol concentration. The GCE' high residual current in aqueous medium makes it impractical in 75% aqueous ethanol and the CPE' solubility in benzene restricts its usage in ethanol‐benzene medium. Slight turbidity does occur sometimes when the unsaponifiable material of the samples is dissolved in 75% ethanol but this seems not to interfere in subsequent analysis. Increase in ethanol content to 90% gives a clearer solution and higher background, but no appreciable difference in the results. The results obtained by use of both electrodes are given and shown to be in close agreement with previously published results.