Multiple Gradient TLC and Densitometric Analysis of p-Coumaric Acid in Some Medicinal Plants from the Family Solanaceae

JPC – Journal of Planar Chromatography – Modern TLC -     

Multiple gradient development TLC in analysis of complex phenolic acids fromLycopus europeaus L.

Summary Phenolic acids fromLycopus europaeus L. (Lamiaceae) were chromatographed on thin layers of precoated silica, LiChrospher silica, propylamine, diol layers using stepwise multiple development and, additionally, on an octadecyl layer with an isocratic mobile phase. The eluent contained decreasing concentrations of formic acid in a mixture of diisopropyl ether-cyclohexane for silica gel plates or methyl-ethylketone inn-hexane for diol plates and increasing concentrations of acetic acid in acetone for the propylamine layer. Extracts were separated into 25 components, 14 of which were identified using a mixture of standards. 2,4-Dihydroxybenzoic, gentisic, protocatechuic and 3,5-dihydroxybenzoic acids were ascribed to this genus for the first time. The adsorbent-eluent systems described were very efficient and rapid.     

Thin-Layer Chromatography and Densitometry of Caffeic Acid in some Dipsacaceae Family Plants

JPC – Journal of Planar Chromatography – Modern TLC - Gradient thin-layer chromatography and densitometry have been used for qualitative and quantitative analysis of caffeic acid in...     

Spectroscopic properties of the Pr3+ ion in TeO2-WO3-PbO-La2O3 and TeO2-WO3-PbO-Lu2O3 glasses

The goal of this work was to investigate the spectroscopic properties of Pr³⁺ ions, embedded in two different tellurite glass matrices, TeO₂-WO₃-PbO-La₂O₃ and TeO₂-WO₃-PbO-Lu₂O₃. The absorption and fluorescence spectra have been recorded and analyzed in terms of the Judd-Ofelt theory along with the luminescence decay of the ³P₀ and ¹D₂ levels of the Pr³⁺ ion. The spectroscopic studies were completed with ellipsometric measurements providing the dispersion relation of the refractive index of the investigated glasses.     

The RP-HPLC analysis of anthocyanins

Summary Conditions were determined for the separation of a complex set of anthocyanins (free aglycones, mono- and multiglycosides and esterified forms) by HPLC. The optimised gradient elution method was then used to carry out qualitative and quantitative analysis of anthocyanin compounds present in the callus tissue ofRudbeckia hirta L. and the tubular flowers of the soil-based plant. The summary content of anthocyanin pigments and the content of the main pigment was identified in the analysed biomass. The method developed is useful for the purposes of monitoring the process of biosynthesis of anthocyanins in tissues obtained through in vitro cultures. The advantages of the method for anthocyanins and its application to other anthocyanin-rich materials are also discussed.     

Two-Dimensional TLC with Adsorbent Gradient for Separation of Quinolizidine Alkaloids in the Herb and In-Vitro Cultures of Several Genista Species

JPC – Journal of Planar Chromatography – Modern TLC - Conditions have been established for TLC separation of a mixture of nine quinolizidine alkaloid standards (lupanine,...     

Determination of Catechin and Epicatechin in an Extract from Uncaria tomentosa Bark by TLC with Chemically Modified Stationary Phases

JPC – Journal of Planar Chromatography – Modern TLC - The conditions used for TLC and HPTLC analysis of catechins have been optimized. Chemically modified stationary phases (HPTLC CN,...     

Resolution of Saponins from a Ginseng Preparation by 2D TLC with an Adsorbent Gradient

JPC – Journal of Planar Chromatography – Modern TLC -