J. Planar Chromatogr. 15, 377-379 (2002). TLC of dyes (methyl red, naphthol red, methyl yellow, azobenzene) on silica gel, open layers and layers covered with a polymeric membrane, with and without mobile phase pressure resulting in an improvement of mixture separation.

Proc. Intern. Symp. on Planar Separations Plan. Chrom. 41-60 (2003). Summary of the progress in forced-flow planar separations (FFPS) and demonstration of the importance of the different forced-flow planar chromatographic (FFPC) techniques like rotation planar chromatography (RPC), overpressured layer chromatography (OPLC), and electro-planar chromatography (EPC) as well as rotation planar extraction (RPE). Special attention was paid to a novel analytical forced-flow high-performance (HP) thin-layer chromatographic (TLC) method, in which continuous development and evaporation of the mobile phase from the end of the chromatographic plate ensure forced-flow development.

Anal. Chem. 76, 1690-1695 (2004). Pressurized planar electrochromatography (PPEC) is a new planar chromatographic technique in which the mobile phase is driven by electroosmotic flow, while the sorbent layer is pressurized in a manner that allows heat to flow from the layer through an electrically insulating, thermally conducting sheet of aluminum nitride ceramic. Separation in a PPEC prototype apparatus is faster than by conventional TLC, and an example is presented of a 24-fold enhancement in the speed of separation. PPEC was performed on TLC and HPTLC RP-18 phases which required conditioning at elevated temperature before use. Solute migration velocity increases with temperature. The flow rate increases in a linear manner with increasing voltage and diminishes in a nonlinear manner with increasing pressure. Both electrical current and Joule heating diminish with increasing pressure, and the diminution of flow at high pressure can be compensated by an increase in voltage. PPEC is more efficient than classical TLC. Theoretical plate heights diminish with increasing hRf and are in the range 29-21 and 55-27 µm for the HPTLC and TLC, respectively. PPEC retains the advantages of classical TLC, but has the ability to separate a substantially higher number of samples. An example is presented on the separation of nine samples in 1 min.

J. Planar Chromatogr. 25, 200-207 (2012). New horizontal developing chamber with advantages for stepwise gradient elution in RP HPTLC. It is shown that a previously developed computer program can be successfully applied to predictive calculations of solute retention in stepwise gradient elution.

J. Planar Chromatogr. 31, 48-56 (2018). HPTLC of _x000D_7 derivatives of 2-(2,4-dihydroxyphenyl)-1,3,4-thiadiazoles A) on silica gel with n-hexane ‒ toluene ‒ acetone 1:1:1 and B) on RP-18 with water – methanol or water – acetone. Changes of retention of chosen compounds were evaluated using perpendicular magnetic field with an inductivity of 0.44 T. Detection under UV 366 nm.

Intern. Laboratory, June 1985, 22 -33.

Detection by spraying with 1 % mercury nitrate, and 0.2 % diphenylcarbazone. Discussion of selecting the optimal system by a stepwise combination method.

Anal. Chem. 59, 2424- 2428 (1987). Use of 2 functions as separation criteria for evaluating 28 solvent systems in the separation of each of 100 subsets of either 6 or 10 steroids. Discussion of the probability of variation and the influencing factors.