Anal. Chem. 58, 582-584 (1986). TLC of 9 racemic mixtures, 3 diasteomeric mixtures and 6 structural isomers on-cyclodextrin-bonded silica with methanol -1 % aqueous triethylammonium acetate (pH 4.1) 5:5. Detection under UV at 254 nm. Evaluation of different silica preparations.

J. Chromatogr. 370, 63-73 (1986). Derivatization of a general equation for the final Rf value of a solute chromatographed under the conditions of stepwise gradient elution with one void volume of mobile phase. Demonstration of a computer program for simulation of stepwise gradient TLC which can be used for optimization. The elution process and the distance travelled by the spots as a function of eluent volumn was illustrated for both displacement adsorption and reversed-phase chromatography.

Miniaturized generators for continuous and stepwise gradients. J. Chromatogr. 446, 275-282 (1988). Description of a miniaturized generator of continuous gradients for equilibrium sandwich chambers with a glass distributor controlling the gradient profile by the initial concentration of weaker eluent and its initial volume and by the composition and rate of delivery of the stronger eluent. Comparison of densitograms from isocratic and gradient TLC. Improvement of the separation under gradient elution conditions.

J. Liquid Chromatogr. 12, 235-246 (1989). Comparison of two data analysis methods, overlapping resolution mapping (ORM) and ideal separation (IS), to optimize the multiple-component mobile phase composition for HPTLC. Evaluation of the separation of 11 anthraquinone dyes using the two methods to select the best mixture of three blends for the mobile phase, composing of benzene, chloroform, tetrahydrofuran, and with each blend having a Snyder’s solvent strength of e = 0.3. Discussion of the results from the two methods. Presentation of resolution contour map for both ORM and IS to find regions of optimum mobile phase composition.

J. Planar Chromatogr. 3, 352-354 (1990). Proposition of a new OPLC development technique where the separation distance can be freely increased by special arrangements of the layers. Several plates are placed on top of each other to extend the developing distance. The end of the first (uppermost) chromatoplate has a slit-like perforation to enable the mobile phase to flow to a second layer where migration continues until the opposite end of the plate. Arrangements for identical plates, different stationary phases, sample clean-up, simultaneous sample application and reconcentration, preparative development, combination of linear and triangular development modes, at low, medium or high external operating pressures are mentioned.

J. Liquid Chromatogr. 15, 1673-1679 (1992). Description of a vacuum driven forced flow planar chromatography device.

J. Planar Chromatogr. 7, 58-62 (1994). TLC of e.g. plant extracts (containing umbelliprenin, imperatorin, bergapten, phellopterin pimpinellin, isopimpinellin, umbelliferone, isobergapten, xanthotoxol) on silica (with preconcentration zone) with diisopropylether - dichloromethane (of increasing eluent strength, with and without different modifiers). Application of isocratic, gradient, and multiple development, as well as simultaneous development using different eluents under different conditions.

J. Chromatogr. Sci. 33, 316-320 (1995). Use of the addition of a-, b-, g-, and hydroxypropyl-b-cyclodextrins to aqueous mobile phases to enhance the migration of p-nitroanilines and their analogues on TLC. Determination of the equilibrium binding constants for the solute-cyclodextrin complexes formed in the mobile phase. Comparison of the results obtained using silica gel and polyamide plates. Urea, which is used to solubilize the cyclodextrins in aqueous solutions, is also found to increase the migration of the compounds.