J. Planar Chromatogr. 15, 258-262 (2002). Preparative TLC of N,N-dimethylaminoazobenzene, 2,6-dinitroaniline, 5-[(diethylaminophenyl)azo]-phthalimide and 4-nitroaniline on silica gel in a saturated horizontal DS chamber with ethyl acetate - heptane 1:19 and ethyl methyl ketone - heptane 1:19. The investigations were performed in the temperature range of 20-40°C. A very significant increase in the efficiency of separation was achieved at higher temperatures. Densitograms used for the presentation of data were scanned in reflectance mode at 400 and/or 500 nm.

J. Planar Chromatogr. 3, 216-221 (1990). Solvent systems for the separation of either steroids or esters of dansyl amino acids in both one-dimensional (1-D) and two-dimensional (2-D) planar chromatography solvent systems are ranked on the basis of simulations of optimized separations, the quality of which is quantified using suitable separation functions. The paper discusses the correlation between solvent ranking in the 1-D and the 2-D mode based upon either the solvent ranks or the actual values of the separation functions. The simulated separations are based on experimental results obtained using either TLC or overpressured layer chromatography.

J. Planar Chromatogr. 5, 334-337 (1992). Discussion of the possibility of calculating optimum values of the differences in chromatographic parameters for the components of separated mixtures on the basis of a retention model based on the law of mass action. The comparison of calculated values with those obtained experimentally on silica eluted with various mixed mobile phases has demonstrated the usefulness of the method.

Anal. Chem. 67, 4423-4430 (1995). Presentation of both first and second-order regression models that relate retention, as the Rf of individual solutes, the log k' of individual solutes, or the average Rf of a mixture of solutes, to the properties of the weak solvent in each of a series of 25 binary mobile phases consisting of a specified concentration of ethyl acetate as a common strong solvent. The stepwise procedure is used for constructing these models, which are for either simulated or experimental separations on silica. Substances chromatographed: Steroids, p-nitrobenzyl esters of dansyl amino acids.

Sz. Nyiredy, A. Kakuk (eds.): Planar Chromatography 2000, Lillafüred, Hungary, 24-26 June 2000, Res. Inst. for Med. Plants, p. 219-229. OPLC of 13 benzodiazepines on HPTLC silica gel with various calculated solvent mixtures up to 15 cm after a pre-run with acetone.

J. Planar Chromatogr. 28, 213-217 (2015). HPTLC of (1) chlorogenic acid, (2) caffeic acid, (3) faradiol and (4) rutin from Calendula officinalis plant extracts on silica gel previously activated at 50 °C in an oven for 30 min. Automated multiple development (gradient elution) with n-hexane, ethyl acetate containing 2 % acetic acid, and water as mobile phase. Detection by spraying with either 10 % sulfuric acid in methanol or 2-aminoethyl diphenylborinate solution followed by placing in oven at 50 °C for 30 min. (1), (2), (3), and (4) were used as markers to investigate and assess the quantitative errors observed. Accuracy of the sample applicator at different sample volumes, the use of a gradient mobile phase, and post-derivatization contribute to uncertainties of the HPTLC method and need to be carefully selected to minimize errors.

Proc. 9th Internat. Symp. Instr. Chromatogr., Interlaken, April 9.-11., 251-259 (1997). General aspects of quality assurance and validation in connection with TLC and the Camag Video Documentation System (including schematic presentation, flow chart of the validation procedure and a chromatogram of a caffeine standard obtained from the CCD image of the HPTLC).

Acta Chromatographica 22 (3), 391-404 (2010). Examination of the effect of conditioning of the silica layer by mobile phase vapor, diethylamine vapor and its aqueous and methanolic solutions, and ammonia vapor on the retention of alkaloids eluted with multicomponent non-aqueous mobile phases. Investigation of the effect of conditioning time and vapor phase composition on system efficiency and peak symmetry, and as well the effect of vapor phase composition on separation selectivity.