Nyiredy, A. Kakuk (eds.): Planar Chromatography 2000, Lillafüred, Hungary, 24-26 June 2000, Res. Inst. for Med. Plants, p. 237-248. Determination of log kw values seem to be very useful for description of biological activity of organic substances (antifungal activity of benzanilides). Very good correlation between log kw values and minimal inhibitory concentration (MIC) values for all benzanilides and dermatophytes is observed. HPTLC of 9 benzanilides on RP18 with methanol and its aqueous solutions. Quantitation by absorbance measurement at 325 nm.

J. AOAC Int. 88, 1537-1543 (2005). HPTLC of caffeine, acetaminophen and acetylsalicylic acid on silica gel with concentration zones using methanol - ethyl acetate 3:17. UV absorption densitometry is used for the quantitative determination of caffeine. Precision, accuracy, linearity, limits of detection and quantitation, and selectivity were validated. - A comparative study using a caffeine standard solution and a multicomponent analgesic tablet solution containing caffeine, acetaminophen, and acetylsalicylic acid showed that manual application on the concentration zone, and instrumental application on the silica gel gave quite similar results in terms of number of theoretical plates, resolution, limit of detection, and linearity.

Universal interaction indices for GLC, HPLC and TLC. Chromatographia 20, 283-288 (1965). Proposal of universal interaction indices used in TLC, GLC and HPLC, which can be easily calculated from commonly used retention parameters, such as Rf values, relative retention times etc. Presentation of the calculation examples for polycyclic aromatic hydrocarbons and n-alkanes. Demonstration of the application of the electric interaction indices for studying the retention mechanism.

J. Planar Chromatogr. 4, 446-450 (1991). Report of theoretical considerations, derived from a new retention model (T. Kowalska, Chromatographia 27, 628-630 (1989)). Insight into the mixed mechanism of solute retention in which intermolecular interactions occur partially with the chemically bonded alkyl groups, and partially with the remaining surface of the solid matrix. Empirical results of suitable experiments seemed to correspond well with the assumed theory.

J. Planar Chromatogr. 9, 164-173 (1996). Comparison of 6 different models of solute retention, devised for reversed-phase liquid chromatography systems, with regard to their predictive power in situations with the competitive occurrence of adsorption and partition as the forces driving retention. The RP-2 stationary phase was selected for the experiments because its ligands are the shortest available and because of the relatively low density of coverage of the silica gel matrix. The initially significant side-effect of adsorption was stepwise quenched by impregnation of the RP-2 layers with increasing amounts of paraffin oil 2.5, 5, 10, and 20%. Methanol - water binary mixtures of different volume proportions were used as mobile phases. Detailed description of the observations made and conclusions drawn from experimental results. Substances chromatographed: 2% solutions of 1-naphthol, 1-naphthylamine, quinoline, 4-methylquinoline, 8-methylquinoline in acetone.

Anal. Chim. Acta 629 (1-2), 66-72 (2008). Presentation of a QSRR approach for prediction of the retention in seven TLC screening systems. Optimization of the model by uninformative variable elimination-partial least squares (UVE-PLS) reduced the variables involved. Final equations with 7 - 32 variables were obtained which explain 32 - 60 % of overall explained variance. Their predictive ability (Q2) includes a range of 25 - 54 % (LOO crossvalidation) and 12 - 43 % (external validation).

J. Liq. Chromatogr. Relat. Technol. 36, 2348-2362 (2013). Nonmicellar 2(1) and micellar (2) TLC of 35 model compounds with different functional groups on silica gel, RP-18 and CN phase with modifiers in hexane and water for (1) and on RP-8 with three surfactants, namely cetyltrimetylammoniumbromide, sodium dodecylsulfate, and Triton-X100 dissolved in water above CMC for (2). A principal component analysis (PCA) allowed for a molecular structure-retention relationship study.

J. Planar Chromatogr. 28, 115-118 (2015). TLC of 35 compounds on RP-18 and cyano phase with six modifiers (acetonitrile, acetone, dioxane, propan-2-ol, methanol, and tetrahydrofurane). The extrapolated Rm data were recomputed and compared to HPLC results with 2 modifiers. HPLC (in gradient mode) and TLC perform in comparable manner in the lipophilicity assessment of the investigated model compounds. With its simplicity, it is a strong argument to use TLC in lipophilicity studies.