Planar Chromatogr. 4, 316-318 (1991). Separation of selected isomers by RPTLC and investigation of the dependence of Rf and RM values on the numerical values of topological indexes. TLC of a- and ß-naphthol and a- and ß-naphtylamine on Kieselguhr G impregnated with a 15% solution of paraffin oil in benzene; development with methanol - water 1:9, detection under UV 254 nm.

Chromatographia 37, 98-104 (1993). RP TLC of title compounds on RP-18 silica with aqueous NH3 (pH 11.19-11.69) - methanol 25:75. Determination of Rf values and calculation of k values. Study of the retention behavior of the compounds as a function of the pH values. Investigation of the effect of composition of the aqueous phase, the molecular structure of the aqueous phase, and the type of organic modifier on the relationship between the retention constant (log k) and the pH of the aqueous phase.

J. Planar Chromatogr. 8, 63-68 (1995). Investigation of the effects of ß-cyclodextrin on the retention of isomeric phenolic and cis - trans cinnamic acids by and RP-HPLC and RP-HPTLC with mixtures of buffer solution and different organic modifiers like methanol, acetonitrile, of tetrahydrofuran.

Part X. J. Planar Chromatogr. 9, 4-15 (1996) TLC of 36 substituted phenols on silanized silica with 0.1 M potassium dihydrogen phosphate in methanol - water 3:7. Detection of chlorophenols with a solution of potassium dichromate (5 g) in 40 % sulfuric acid followed by heating at 110 °C for 15 min. Detection of methylphenols with methanolic iron(III)chloride solution or titanium tetrachloride in 20% HCl followed by heating at 120°C for 30 s resp. 2 min; detection of nitrophenols with a 1% solution of p-nitrobenzene-diazonium fluoroborate in acetone. After separation the pKa values of the compounds have been correlated with RM values and with numerical values of the topological indexes.

Comparison with the adsorption properties of Florisil. Chromatographia 43, 405-412 (1996). Examination of the retention behavior of positional isomers and polyaromatic hydrocarbons on mixed silica - magnesia layers with various binary eluents. Investigation of the influence of magnesia content in mixed adsorbents and concentration of polar modifier in the eluent on retention. Comparison of the results with those obtained on Florisil using the same eluent by RM correlation. Comparison of chemical character and distribution of active centers on Florisil and mixed adsorbent surfaces by analysis of the structural effects of solutes and the position of points on RM correlation diagrams.

J. Planar Chromatogr. 11, 283-294 (1998). Examination of the retention of different groups of model substances - 16 phenols, 12 amines, 6 quinoline bases - on polar adsorbents - silica gel, alumina, and Florisil - developed with isoeluotropic eluents. The DRM (Dlogk, selectivity) parameters for different substituents of the compounds were compared as parameters of the energies of adsorption of the various chromatographic systems. The DRM values for substituents were correlated with their reactivity constants.

Sz. Nyiredy, A. Kakuk (eds.): Planar Chromatography 2000, Lillafüred, Hungary, 24-26 June 2000, Res. Inst. for Med. Plants, p. 183-193. The retention behavior of 7 monotetrazolium and 9 ditetrazolium salts were studied by spectral mapping technique. Tetrahydrofuran has the highest solvent strength while the differences among ethanol, 1-propanol, 2-propanol and dioxane were relatively low. The selectivity of tetrahydrofuran was different from those of others. Hydrophobicity and electronic parameters were equally involved in the retention strength and selectivity indicating the mixed character of their interaction with the alumina stationary phase and impregnated one.

J. Planar Chromatogr. B, 152-159 (2001). Review of the use of topological indices based on the adjacency and distance matrixes to predict the Rf and RM values, and the physicochemical properties of a variety of groups of organic compounds investigated by TLC. (131 references).