Comparison of Different Fluorimetric Signals for the Simultaneous Multivariate Determination of Tocopherols in Vegetable Oils

Abstract

This paper deals with the simultaneous determination of the quaternary mixture of tocopherols (alpha-, beta-, gamma-, and delta-T) performed using fluorimetric techniques and partial least squares (PLS-1) multivariate analysis. In this study, PLS-1 was applied to matrices made up of fluorescence excitation and emission spectra (EEM) and with fluorescence excitation, emission, and synchronous spectra (EESM) of tocopherols dissolved in hexane: diethyl ether (70:30 v/v). A calibration set of 55 samples based in a central composite plus a full factorial plus a fractionated factorial design was constructed. When synthetic samples were analyzed, recoveries around 100% were obtained and detection limits were calculated using EEM and EESM. For the analysis of the oils, the samples, diluted in hexane, were cleaned in silica cartridges and tocopherols were eluted with hexane: diethyl ether (90:10 v/v). The developed method was applied to different edible oils. The results are satisfactory for alpha-, beta-, and gamma-, but they are worse for delta-T.

Evaluation of total phenolic content in virgin olive oil using fluorescence excitation–emission spectroscopy coupled with chemometrics

“…We attribute these distinct emissions to phenolic compounds and tocopherols. Several authors have suggested that the emission of olive oils (and other vegetable oils) in the short‐wavelength range originates from phenols and tocopherols . This assignment was based on the spectral characteristics, as well as observed quantitative relationship between the emission in this range and concentration of tocopherols or phenolic compounds.…”

Development of chitosan based microencapsulated spray dried powder of tuna fish oil: oil load impact and oxidative stability

“…Tocopherol is an important parameter for assessing the oxidative status of an oil Galeano Díaz et al (2006). In current study oxidative stability was evaluated through PV, AV and additionally through quantification of tocopherols.…”

Kinetic study of the reaction of thiophene-tocopherols with peroxyl radicals enlightenings the role of O˙⋯S noncovalent interactions in H-atom transfer

“…48 Tocopherols present absorption and emission peaks centered at approximately the same wavelength 49 and, even if several methods for the determination of tocopherols have been published, [50][51][52][53][54] their determination in a mixture is not feasible by the conventional fluorimetric technique. 55 It should be highlighted that spectroscopic methods show clear advantages over chromatographic techniques for the analysis of one or a few analytes, such as lower consumption of solvents, shorter analysis times, and lower cost of equipment. 55…”

“…55 It should be highlighted that spectroscopic methods show clear advantages over chromatographic techniques for the analysis of one or a few analytes, such as lower consumption of solvents, shorter analysis times, and lower cost of equipment. 55…”