RESUMO
Principles and problems in the development of simultaneous liquid chromatography (LC) analytical methods for potent antioxidative molecules resveratrol, tocopherol, and coenzyme Q10 in capsules, have been investigated and systematically compared and summarized. For these purposes, experiments within the full polarity spectrum of LC techniques. were tested and recorded. The whole range of polarities included: Alkyl C18 bonded reversed phase, phenyl, cyanopropyl, diol, and the most polar base silica-filled column matrixes have been used. The summarized results concluded that all mentioned LC techniques could be used for the determination of the mentioned group of the three analytes with different run characteristics and efficiency. These successes could be achieved after careful analyses of molecular physicochemical data of analytes. They are especially organic solubilities. The ultraviolet spectral absorption characteristics of each analyte and the mobile phase constituents for appropriate separation were very important to be known. The ultimate targets were the development method with the isocratic mode of separation yielding symmetrical peak shapes for the best sensitivity and accuracy, with the shortest run time and best reproducibility. From an analytical point of view important for LC, the three analytes have quite distinct characteristics that contribute to successful method development. These features are their organic solvent and water solubility, molecular polarities, and ultraviolet-absorption characteristics, like spectra and absorptivities. All these mentioned parameters were taken into account for solving complications appearing in the development of rapid LC methods for the simultaneous determination of three antioxidant molecules.
Assuntos
Antioxidantes , Ubiquinona/análogos & derivados , Vitamina E , Cromatografia Líquida de Alta Pressão/métodos , Resveratrol , Reprodutibilidade dos Testes , Cromatografia Líquida/métodosRESUMO
BACKGROUND: There is an increasing interest in the use of a combination of trans-resveratrol and vitamin E in dietary supplements. Determination of the content of both components is essential for confirmation of the quality of the product. OBJECTIVE: To establish the applicability and ensure the greenness of the previously developed high-throughput HPLC/UV method for the simultaneous determination of trans-resveratrol and alpha-tocopherol acetate (vitamin E) in dietary supplements. METHOD: Separation was performed on RP C8 Select B chromatographic column, using acetonitrile and water in the mobile phase, with gradient elution. Full method validation was performed in accordance with ICH Q2(R1). The greenness of the method was assessed using the analytical eco-scale (AES) methodology and the analytical greenness metric (AGREE). RESULTS: The method is selective, linear, precise, and accurate over defined concentration ranges (185-369 µg/mL of trans-resveratrol and 37-75 µg/mL of alpha-tocopherol acetate), and it has a suitable sensitivity (limits of detection and quantification are 7.7 and 23.3 µg/mL for resveratrol and 2.6 and 7.8 µg/mL for tocopherol acetate, respectively). The obtained analytical eco-scale score of 77 and the pale green AGREE pictogram with an overall score of 0.61 confirm the method's greenness. CONCLUSIONS: The sensitivity and selectivity of the method, its short analysis time (7 min), the low negative environmental impact, and the simple sample preparation make the method readily applicable to inline quality control procedures. HIGHLIGHTS: A method for simultaneously analyzing vitamin E and resveratrol in dietary supplements is presented. The method is rapid, includes a simple sample preparation procedure, and has a low environmental impact.