Chronopotentiometric analysis of tocopherols using a glassy carbon vessel as the working electrode

Abstract

Using a specific electrochemical cell with a glassy carbon vessel as the working electrode, a significant enhancement of the chronopotentiometric determination of tocopherols was achieved. Due to the large area of the working electrode, the method sensitivity was increased approximately 50-fold compared to the common electrochemical cell with a glassy-carbon disc electrode. Limits of quantitation of approximately 0.35 mg/dm3 for α-, γ- and δ-tocopherol were obtained. The influence of the most important experimental factors was investigated and the method defined was applied for tocopherol determination in crude vegetable oils. The tocopherol content was determined by standard solutions prepared in a matrix of animal fat. An absolute method for γ- and δ-tocopherol quantitation is also described. © 2002 Elsevier Science B.V. All rights reserved.