Determination of individual tocopherols by derivative spectrophotometry

The second order derivative UV spectra of α‐, β‐, γ‐ and σ‐tocopherols showed small differences that allowed development of a derivative spectrophotometric method for determining individual tocopherols in a mixture. The procedure consists of measuring the second derivative spectrum of the sample at four specified wavelengths and calculating each concentration by means of a method for multicomponent analysis that uses mixtures as standards. Vegetable oils and other fatty products usually require a previous clean‐up process (under study) in order to remove interfering substances.