J. Planar Chromatogr. 10, 441-446 (1997). Determination of lipophilicity and specific hydrophobic surface of 11 sulfosuccinic acid esters by RP TLC in ion-free eluents and in eluents containing NaCl, KCl, MgCl2, and CaCl2. The strength and selectivity of the effect of salts were separated by use of the spectral mapping technique. Stepwise regression analysis was used to elucidate the relationship between the retention characteristics and the physicochemical parameters.

Chinese J. Chromatogr. (Sepu) 17, 14-17 (1999). Determination of the Rf values of a group of amino acids by normal phase TLC. Computation of the correlation coefficients for various parameters of amino acids. Classification of the parameters according to the results of correlation analysis. Studies of the title relation-propagation artificial neural network. Comparison of the results with those obtained experimentally, showed good agreement.

J. Planar Chromatogr. 12, 408-415 (1999). Investigation of the influence of a perpendicular homogeneous electric field on the TLC process for four different sorbents, SiO2, Al2O3, cellulose and polyamide; description of the influence on mobile phase migration time, on chromatographic parameters, and on the properties of the sorbent layers developed with monocomponent mobile phase, from apolar solvents such as hexane and heptane to strong polar phases such as methanol, formamide and water, using two substance groups as samples - inactive compounds (polycyclic hydrocarbons) and substances with active substituents (quinoline derivatives).

J. Planar Chromatogr. 14, 439-444 (2001). After separation of homologous series of higher fatty acids, higher alcohols, and methyl esters of higher fatty acids the RM values and the partition coefficients could be correlated with numerical values of topological indexes based on the adjacency matrix and on the distance matrix. Partition TLC of lauric, myristic, palmitic, stearic acid, and the corresponding alcohols and methyl esters on kieselguhr impregnated with a 10% or 15% solution of paraffin oil in hexane with methanol - water 9:1 and ethanol - water 9:1. Visualization by spraying with bromothymol blue or with a 0.005% aqueous solution of new fuchsin.

Part II. J. Chromatogr. A 1007 (1-2), 157-164 (2003). Quantitative structure–activity relationship (QSAR) analysis of H1-antihistamine activity was carried out and chromatographic data of 2-[2-(phenylamino)thiazol-4-yl]ethanamine, 2-(2-benzyl-4-thiazolyl)ethanamine, 2-(2-benzhydrylthiazol-4-yl)ethylamine derivative, and 2-(1-piperazinyl- and 2-(hexahydro-1H-1,4-diazepin-1-yl)benzothiazole derivatives were obtained. Silica gel impregnated with solutions of selected amino acid mixtures (-Asp, Asn, -Thr and -Lys) were used in two developing solvents as human histamine H1-receptor (hH1R) antagonistic interaction models. Lipophilicity data of the examined compounds were obtained and used in the QSAR assay. Using regression analysis, relationships between chromatographic and biological activity data were found. The correlations obtained in the present experiment with NP-TLC are more significant that those obtained in the experiment with RP2-TLC because of the optimal fitting of the chromatographic system conditions to the lipophilicity of solutes. All proposed chromatographic models should facilitate pre-selection of the new drug candidates. The correlations of calculated pA2(H1) values of the tested compounds predicted by the use of the best equations versus their pA2(H1) obtained from the biological tests were significant (R2= 0.91-0.94).

J. Planar Chromatogr. 20, 307-308 (2007). The water content of stationary phases as well as controlling the water content are very important for obtaining reliable separation results in TLC. Dimroth’s salt (today widely known as Reichardt’s dye), 4-(2,4,6-triphenylpyridinium) 2,6-diphenylphenoxide, can not only be used to measure the water content of solvents; it was found to be suitable for easily checking of the water content of TLC layers: A solution of 2,6-diphenyl-4-(2,4,6-triphenyl-1-pyridino)phenolate hydrate in acetone (1.65 mg/mL) was applied to the plate as spot or as a band. The plate was stored in an oven at 120 °C for 30 min then left for 20 min over sulfuric acid of different concentrations which resulted in relative humidity from 9 to 72 %. From the spot spectra measured directly between 400 to 900 nm absorption spectra can be calculated; an inverse linear relationship exists between the absorption at 500 nm and water content. Spots of Dimroth’s salt are suitable for checking the water content of TLC plates. Simply measuring the dye absorption at 500 nm and comparison with a calibration plot reveals the water content of the layer.

J. Chromatogr. A 1483, 138-141 (2017). Investigation of the eluotropic strength on silica gel for 20 chromatographic grade solvents available in current market, using 35 model compounds as test subjects. Estimation of each solvent as a separate elution coefficient with an acceptable error (0.0913 of RM value) by employing modern mixture screening design. Check of the distribution and uncertainty of eluotropic estimates by additional bootstrapping technique, proving very similar confidence intervals to linear regression. Principal component analysis revealed that only one parameter (mean eluotropic strength) is satisfactory to describe the solvent property, as it explains almost 90% of variance of retention. Comparison of the obtained eluotropic data with previously published series showed that the two are in a general agreement and their values can be interpreted in context of RM differences.

RM and log P values. J. Chromatogr. 498, 179-190 (1990). Measurement of the RM values of a series of xanthine and adenosine derivatives on silicone-impregnated silica and C-18 silica with aqueous glycine buffers (pH 9.0) or sodium acetate veronal buffer (pH 7.0), alone or mixed with various amounts of acetone. Correlation of the two series of data obtained. Comparison of experimental log p values with calculated ones. The TLC data proved to be reliable for describing the lipophilic properties of the test compounds.