edition of Formulae normales by thin-layer chromatography. Acta Pharmazeutica Hungarica 60, 77-83 (1990). TLC on silica with acetone – ether- water 90:15:12 for aminophenazone, benzene – acetone – ethanol 90% – water 35:33:26:11 for noraminophenazone sodium mesyl, methanol – acetic acid – ether – benzene 1:18:60:120 for acetylsalicylic acid, dichloromethane – methanol – NH3 conc. 85:15:2 for ethylmorphine hydrochloride. Detection under UV and by spraying with alcoholic ninhydrin and dimethylamino benzaldehyde solution.

Anal. Biochem. 191, 309-313 (1990). Two-dimensional TLC of three adenosine derivatives on cellulose with a) isobutyric acid - 25% NH3 - water 50:1.1:28.9, b) 0.1 M sodium phosphate, c) hydrogen chloride - isopropanol - water 15:70:15. Determination of the polymer sizes and the number of branching points of in vitro synthesized poly (ACP-ribose). Comparison of the results with those obtained by strong anion-exchange HPLC. The results obtained by both methods were in complete agreement.

J. Planar Chromatogr. 4, 330-332 (1991). HPTLC separation of chlordiazepoxide, demoxepam, and ACB (2-amino-5-chlorobenzophenone) on silica (after cleaning by successive development with ethyl acetate aqueous NH3 - methanol 1:9. ‚Related‘ cpds were separated with ethyl acetate in a saturated chamber, chlordiazepoxide with aqueous ammonia - acetonitrile 1:999 in an unsaturated chamber. Quantification by densitometry (absorbance at 254 nm).

Biochemical Systematics and Ecology 22, 353-365 (1994). TLC of ethanol extracts on silica with ethyl acetate - heptane 1:1, dichloromethane - ethanol 9:1, butanol - acetic acid - water 6:3:1. Visualization by spraying with 5% vanillin-sulfuric acid reagent followed by heating.

J. Planar Chromatogr. 8, 238-240 (1995). TLC of sulfadiazine, sulfadimidine, sulfadimetoxine, sulfaquinoxaline on silica with ethyl acetate - dichloromethane 4:1 after preconcentration with acetonitrile. Detection after drying by spraying with a 0.02 % solution of fluorescamine in acetone, and observation under UV 366 nm.

J. Planar Chromatogr. 9, 138-141 (1996). HPTLC of cisapride and degradation products on silica with chloroform - methanol - toluene - acetic acid 70:30:60:3 in a chamber conditioned with the solvent system for 30 min. Quantification by densitometry at 307 nm. Detection limit 10 ng. Fast, sensitive, and specific TLC method.

J. Planar Chromatogr. 9, 388-390 (1996). HPTLC of verapamil hydrochloride (5-[N-(3,4-dimethoxyphenethyl)-methylamino]-2-(3,4-dimethoxyphenyl)-2-isopropylvaleronitrile monohydrochloride) on silica with ethyl acetate - methanol - water 100:13:10. Quantification by densitometry (absorbance) at 278 nm. Intraday and interday precision were 0.17-0.62% and 0.88-1.00%, respectively.

Proc. 9th Internat. Symp. Instr. Chromatogr., Interlaken, April 9.-11., 387-389 (1997). Elaboration of TLC methods that were reproducible and as simple as possible for the testing of finished products containing active substances from the Essential Drug List. The purposes of the search for suitable TLC conditions for the different substances are: 1. Detection of the identity of various pharmaceutical preparations (and if possible also the purity of the active substances, including testing for decomposition products); 2. Preparation of samples and implementation of TLC should involve the simplest procedures possible; 3. Only precoated plates with as few as possible common stationary phases from different manufacturers should be used; 4. The mobile phase systems should be as simple and non-toxic as possible and cause minimum pollution of the environment; 5. Special reference substances should not be necessary.