Proc. Intern. Symp. on Planar Separations Plan. Chrom. 399-405 (2003). TLC of 4-phenyl-1-butanol, 5-phenyl-1-pentanol, 3-phenylpropionic acid and 3-phenylbutyric acid on cellulose with i.e. decalin in the classical chamber of Stahl-type and the sandwich-type. Densitometry at 260 nm in reflectance mode. It was clearly demonstrated that, under the conditions used, the sandwich-type chamber can by no means be considered as superior to the Stahl-type chamber.

TrAC 25, 8 (2006). In the individual monographs of drug substances or finished products, only semi-quantitative TLC purity tests are mentioned and the number of TLC applications is steadily decreasing, being replaced by HPLC methods that are considered more appropriate. However, to comply with the latest and current pharmaceutical regulations, TLC manufacturers do not stop developing new equipment and accessories related to sample application, developing chambers, derivatization, documentation, and quantitative evaluation. Numerous examples of TLC/HPTLC applications in analytical research and quality control are mentioned to show the validity of this technique in the description of organic related impurities in drug substances and final products. Finally, authors ask analysts to present excellent, fully-validated and documented GMP/GLP-compliant TLC purity-test procedures to convince experts from pharmacopoeial committees and regulatory bodies of the importance of this analytical tool.

Chromatographia 20, 739-742 (1986). Discussion of the effects of stabilizers such as 2, 6-di-tert-butyl-4-methyl-phenol and hydroquinone and impurities in solvents on the reproducibility of the quantitative analysis (stability tests) of mebeverine by HPTLC.

J. Chromatogr. 402, 358-360 (1987). TLC of phenolic acids on Fe(III)-impregnated silica with distilled, tap and sea water. Detection by spraying with bromocresol green indicator reagent and a 1% aqueous solution of Fe(III) nitrate, and by inspection under UV. Discussion of the mobility of Fe(III)-phenolic acid complexes.

J. Chromatogr. 439, 317-339 (1988). TLC on silica with a) cyclohexane - toluene - diethylamine 75:15:10, b) chloroform - methanol 9:1, c) chloroform - acetone 8:2 for benzodiazepines and a) toluene, b) toluene - isopropanol - NH3 85:15:1, c) chloroform - methanol 9:1, d) chloroform - acetone 8:2 for benzophenones. Detection under UV and by spraying with iodoplatinate solution for the former and with Bratton- Marshall test for the latter.

J. Liquid Chromatogr. 12, 979-985 (1989). TLC of some carboxy and hydroxy benzene derivatives related to lignin and humic materials on silica and Fe(III)- impregnated silica with 1) ethyl acetate, 2) ethyl acetate – benzene 9:11 and 3) ethyl acetate – benzene 5:15. Identification of the compounds tested by the mobility differences on impregnated and plain plates.

1. Effect of temperature on Rf values.) (Japanese). Kagaku to Kyoiku (Jap. J. Educ.) 42, 206-210 (1994). Examination of the effects of temperature on Rf values in TLC, with some dyes and simple organic compounds, e.g. nitrobenzene, phenol, etc., and steroids as analytes.