Comparative Evaluation of Vegetable Oils-Impregnated Layers as Reversed-Phases for Thin-layer Chromatography

摘要

Silica gel plates impregnated with a variety of oils including vegetable oils (olive, sunflower and corn oil) and synthetic oils (trioctylamine and paraffin oil) were evaluated and compared with the commercially available reversed-phases TLC plates (RP-18, RP-18W, and CN). A series of selected lipophilic vitamins was employed to evaluate the suitability of oils as reversed-phases for TLC and to provide different lipophilicity indices: R _M0, scores corresponding to the first principal component of R _F and/or R _M, the arithmetic mean of R _F and R _M values obtained with solvent mixture containing various concentrations of methanol in water. The retention results were excellent (r > 0.98) and allowed accurate estimation of lipophilicity of selected vitamins and to ranking the lipophilicity of oils when comparing with chemically bonded phases. Concerning the lipophilicity scale of vegetable oils, it is worth noting that corn oil presents the highest lipophilicity, closely followed by the olive and sunflower oils.