Chromatographia 65 (3-4), 239-243 (2007). Description of a novel TLC densitometric method for the determination of solasodine in various Solanum species (Solanaceae). Solasodine does not show UV absorption therefore TLC of an ion pair complex of solasodine with an acid dye was performed. TLC plates developed by using a solvent with an organic acid ensured in situ color development of the complex. Densitometry at 461 nm. Linearity was 79.2 - 495 ng/zone, with a correlation coefficient of 0.995. The method shows good reproducibility, specificity and accuracy (98.54 ± 2.8%), and eliminates post derivatization steps and the problem of background interference. Validation of the method and application of the method to determine solasodine content in various herb samples, herb extract and their formulations, without matrix interference observed.

J. Liq. Chromatogr. Relat. Technol. 28, 1765-1775 (2005). TLC of cholic acid, glycocholic acid, glycodeoxycholic acid, chenodeoxycholic acid, deoxycholic acid, lithocholic acid, and glycolithocholic acid, on RP-2 phase with methanol - water, organic mixture (acetonitrile - methanol 1:1) - water, acetone - water, dioxane - water in different volume compositions. Detection by dipping in 10 % ethanolic phosphomolybdic acid solution and heating at 120 °C for 20 min.

Studied by Different Chromatographic Techniques. Chromatographia 63 (Supplement 13), S81 - S86 (2006). TLC of isoquinoline alkaloids (chelidonine, chelerythrine, sanguinarine, coptisine and berberine) in Chelidonium plant organs on silica gel with chloroform - methanol 2:1, and methylene chloride - methanol 97:3. Quantification by densitometry at UV 254 nm. Detection is very sensitive because of fluorescence of alkaloids without purification. Comparison with HPLC, showing that the TLC methodis the most simple, accurate, reproducible and convenient analytical technique for fast investigations and routine determination of Chelidonium alkaloids.

J. Liq. Chromatogr. Relat. Technol. 28, 2285-2291 (2005). TLC of flavonoids with vitexin and quadrangulosides as standards on silica gel with ethyl acetate - acetone - acetic acid - water 6:2:1:1, and saponins with chloroform - ethanol - acetic acid 12:8:1. Detection by spraying with anisaldehyde-sulfuric acid reagent, then heating to 100 °C. Also detection by spraying with a 0.5 % methanolic solution of diphenylboryloxyethylamine (natural products reagent) followed by spraying with 5 % PEG 400. Evaluation under white light and UV 365 nm.

Influence of diluents and adulterants. J. Liq. Chromatogr. Relat. Technol. 28, 2875-2886 (2005). TLC of the active components of „ecstasy“ (MDMA, PMA, PMMA, and ephedrine) on silica gel with 10 mobile phases. The simplex method has been employed to find the optimum composition of the eluent chloroform - dioxane - methanol - ammonia - acetonitrile 7:30:4:3:30. Detection under UV light at 254 nm.

J. Liq. Chromatogr. Relat. Technol. 28, 1703-1716 (2005). TLC of kavalactones (kavain, 7,8-dihydrokavain, methysticin, 7,8-dihydromethysticin, yangonin, and demethoxyyangonin) on silica gel with the organic layer of n-hexane - ethyl acetate - methanol - water 6:5:6:5. Detection by spraying with anisaldehyde - sulfuric acid followed by heating.

J. Planar Chromatogr. 20, 399-406 (2007). General aspects of food analysis using planar chromatography as an optimum tool for national and international standards to keep analysis economical. Contents: 1. The changing situation as a challenge; 2. TLC and HPTLC applications in food analysis and rapidly growing topics; 2.1 Topics in the past twenty years; 2.2 Rapidly growing topics in the future; 3. Is HPTLC a reliable quantitative method in food analysis; 3.3 Performance key data; 3.2 Method comparison; 3.3 Separating power; 4. Obstacles and benefits of planar chromatography; 4.1 Obstacles; 4.2 Benefits; 5. Future potential of HPTLC in food analysis; 5.1 Simplified sample preparation; 5.2 Simultaneous determination of analytes with different detection principles or analytes difficult to detect in general; 5.3 Digital evaluation of plate images; 5.4 Bioactivity-based detection; 5.5 Mass-selective information on demand; 5.6 Cost-effectiveness; 6. Conclusions. Planar chromatography for simple solution of difficult problems, reduced sample preparation, selective derivatization, quantitative and sensitive determinations using appropriate instrumentation, compliance with regulated environments, e. g. cGMP and cGLP, validation fulfilling requirements for reliable analysis, reduced costs, high throughput and comparable results.

J. Planar Chromatogr. 20, 141-143 (2007). TLC of methyl, ethyl, propyl p-hydroxybenzoate, p-hydroxybenzoic acid, benzoic acid, sodium benzoate, butylated hydroxyanisol, and butylated hydroxytoluene on the inorganic ion exchanger stannic silicate in a twin-trough chamber with n-hexane - ethyl methyl ketone - acetic acid 80:20:3. Quantitation by scanning densitometry at 260 nm.