J. Planar Chromatogr. 1, 182- 187 (1988). Discussion of sample application in planar chromatography involving fundamentals, negative aspects, systematic errors, accuracy, precision, working range, coupling to other techniques and the practical solution.

J. Chromatogr. 466, 227-232 (1989). Chromatography of 20 complexes of Cr(III), Co(III), Ru(III), Rh(III), Fe(II), Co(II), Ni(II) and Zn(II) containing ligands. TLC on silica or alumina with 22 single-component solvents. Determination of their Rf values. Explanation of the results obtained for anionic and neutral complexes by using the polarization power of the central ions of the complexes, assuming an adsorption separation mechanism.

J. AOAC Int. 74, 435-437 (1991). In this paper the author emphasizes that there are many areas where TLC has a good future due to higher sample throughput, ability to analyze crude samples, wider choice of solvents, selective reagent sprays, ability to see irreversibly absorbed fractions, low cost and low solvent use.

J. Planar Chromatogr. 10, 273-280 (1997). Discussion of practical aspects of method development in HPTLC. Examples of typical problems that have been solved as part of a method development course at CAMAG Scientific's application lab illustrate the flexibility and ease of use which make modern planar chromatography an attractive choice among analytical tools. Practical aspects of method development consist of: 1. Analyzing the goal; 2. Finding a suitable developing solvent; 3. Optimizing the visualization and evaluation process; 4. Improving sample application and sample clean-up; 5. Method validation. Short description of the spot test, the Four Solvent or Selectivity Triangle Approach, the PRISMA Model, followed by some examples of typical goals for method development. Also published in Proc. 9th Internat. Symp. Instr. Chromatogr., Interlaken, April 9.-11., 273-288 (1997).

Part 2. Systematic errors caused by separation systems. J. Planar Chromatogr. 18, 118-126 (2005). Discussion of systematic errors in analytical PLC data. Second part of a series covering fundamentals of systematic quantitative errors caused by separation systems, evaluation and calibration errors, nonlinear separation and quantitation techniques, the sf4 procedure for finding total systematic errors, systematic errors caused by regulations, and conclusions and proposals for quantitative planar liquid chromatography. 1) Great number of different separation systems. 2) Separation system and mobile phase. 3) Multiple and forward-backward runs - circular and linear systems. 4) Fast and small is better and reduces systematic errors. 5) Type of separation system and quantitation mode. 6) Clean calibration substances available through a special mode of separation. 7) The gas phase in PLC. 8) Fundamentals of different separations systems (1. Important factors 2. Summary). 9) Possibilities and trends and the state of the art today; proneness to errors number (PEN).

Proc. Intern. Symposium on TLC with special Emphasis on OPLC, Szeged, 43-44 (1984). OPLC (OPTLC) of 4-cyano-phenylesters, triazine derivatives on silica with methanol - water and acetonitrile - water in seven different proportions. Detection with o-toluidine. The RM-values obtained by OPTLC are in good agreement with RM-values in normal chambers.

Anal. Chem. 63, 1524-1529 (1991). Application of a parameter, c, for planar chromatography in either normal - or reverse phase mode to each of a series of week solvents used in a binary mixture with a given strong solvent. Also to a series of strong solvents used with a given week solvent. A linear relation between either the average Rf of solutes or the Rf of individual solutes and the value of c for each of the series of solvents was found for many of the systems studied. Use of the relation to predict the retention of a solute when a mobile phase of known c is used. Discussion of the relation between c and established solvent strength parameters.

J. Planar Chromatogr. 7, 147-152 (1994). Continuation of the paper ref. 73 011, investigating the mobile phases, propanol - hexane, isopropanol - hexane, butanol - hexane.