Simultaneous Electrochemical Determination of alpha-Tocopherol and Retinol in Micellar Media by a Poly(2,2 '-(1,4 Phenylenedivinylene)-bis-8-Hydroxyquinaldine)-Multiwalled Carbon Nanotube Modified Electrode

Abstract

A novel method was developed for the simultaneous electrochemical determination of alpha-tocopherol (viatmin E) and retinol (vitamin A) using a poly(2,2'-(1,4-phenylenedivinylene)-bis-8-hydroxyquinaldine)/multiwalled carbon nanotube modified glassy carbon electrode. The simple and rapid voltammetric approach was evaluated for real samples using Triton X-100 to solubilize the analytes in the absence of organic solvent. The calibration graph for alpha-tocopherol was linear from 8 to 100 mu M with a limit of detection of 0.1 mu M in the presence of 80 mu M retinol. The response was also linear with retinol concentration from 5 to 200 mu M with a detection limit of 0.8 mu M in the presence of 40 mu M alpha-tocopherol. The developed method was employed for the determination of the vitamins in pharmaceutical products.