J. Planar Chromatogr. 21, 61-66 (2008). Investigation of overloading, methods of sampling, effect of layer thickness on band resolution, and the effect of derivatization on the location of the separated band. Another objective of the work was the investigation of the use of unidimensional multiple development (UMD) and incremental multiple development (IMD) for resolution of the alkaloids from Fumaria officinalis extracts. TLC of medium polarity alkaloids and strongly polar alkaloids on silica gel with acetic acid - propanol - water 1:4:5 and with acetic acid - water - methanol - dihloromethane 2:1:8:29 (UMD technique), and with acetic acid - propanol - dichloromethane 1:4:5 (IMD technique). Detection by derivatization with Dragendorff reagent. Quantitation by densitometry at 520 nm.

J. Planar Chromatogr. 21, 27-32 (2008). TLC of extracts of Stachys recta and harpagide, acetylharpagide, harpagoside, ajugoside, and aucubin on silica gel with chloroform - methanol - water 25:10:1. Visualization by spraying with Ehrlich’s reagent (1 % solution of dimethylaminobenzaldehyde in concentrated hydrochloric acid) followed by heating at 105 °C for 5 min. Densitometric evaluation at 540 nm.

J. Sep. Sci. 31, 237-241 (2008). HPTLC of chlorogenic acid in green coffee beans on silica gel with ethyl acetate - dichloromethane - formic acid - acetic acid - water 100:25:10:10:11. Quantitative determination by absorbance measurement at 330 nm. The hRf value was 27 and selectivity regarding matrix was given. Linearity was between 550 and 1750 ng/spot. The limits of detection and quantification were 80 and 250 ng, respectively. Recovery was 97.1 %. The intermediate/interday/intra-day precision was between 1.06 % and 1.35 % (n=6). The data showed no statistically significant differences for HPTLC and HPLC methods.

J. Liq. Chromatogr. Relat. Technol. 30, 2267-2285 (2007). Analytical and preparative TLC of lipid classes, their fatty acid profiles, and the triacylglycerol and sterol composition on silica gel and modified silica gel (impregnated with silver nitrate for Ag-TLC or dimethyldichlorosilane for RP-TLC). TLC of lipid reference mixture on silica gel with hexane - acetone 25:4. Detection by spraying with 50 % ethanolic sulfuric acid and heating at 200 °C. Preparative TLC for isolation and quantification, followed by detection under UV light, spraying the edges with 2’,7’-dichlorofluorescein, scraping off, elution with diethyl ether and weighting. Quantitative Ag-TLC (impregnated by dipping into 0.5 % or 2 % methanolic solution of silver nitrate) followed by detection with bromine and sulfuryl chloride vapor for 30 min each, followed by heating at 180-200 °C. Preparative Ag-TLC with 4 different mobile phases. Quantitative RP-TLC on Kieselguhr treated for 6 h with vapors of dimethyldichlorosilane and washed with methanol using acetone - acetonitrile - water. Quantitative determination by absorbance measurement at 450 nm.

J. Liq. Chromatogr. Relat. Technol. 30, 2209-2219 (2007). HPTLC of artemisinin in Artemisia annua on silica gel with cyclohexane - ethyl acetate - acetic acid 20:10:1 in a twin-trough chamber saturated for 20 min. Detection by immersion in modified anisaldehyde reagent (20 mL acetic acid, 4 mL sulfuric acid, 2 mL of anisaldehyde in a mixture of 100 mL ethanol and 80 mL water) for 1 s. After 1 min the plate was heated at 100 °C for 12 min. Quantitative determination by fluorescence measurement at 520 nm with cut-off filter at 540 nm.

J. AOAC Int. 91, 1331-1338 (2008). HPTLC of ciprofloxacin (1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(piperazin-1-yl)quinoline-3-carboxylic acid hydrochloride) and degradation products (7-[(2-aminoethyl)amino]-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-quinoline-3-carboxylic acid and 7-amino-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-quinoline-3-carboxylic acid) on silica gel with chloroform - methanol - 25 % ammonia 43:43:14. Detection with 0.3 % methanolic ninhydrin solution and dimethylaminobenzaldehyde and quantitative determination by absorbance measurement at 277 nm.

J. Food Comp. Anal. 21, 577-581 (2008). HPTLC of a novel fluorescent compound of nutmeg (Myristica fragrance) on silica gel with hexane – diethyl eter – acetic acid 50:50:1. Detection under UV at 265 nm or by spraying with sulphuric acid 50% followed by heating at 180 °C. The major fluorescent band at hRf 63 was further purified on silica gel using dioxane – acetonitrile – acetic acid 70:30:1. The hRf value of the novel compound was 61. Quantitative determination by absorbance measurement at 376 nm. Linearity was between 1 to 50 µg/spot. The compound was identified as 2-methyl-1,4,4a,8a-tetrahydro-endo-1,4-methanonaphthalene-5,8-dione.

60th Indian Pharmaceutical Congress PA-194, (2008). HPTLC of bumetanide on silica gel with toluene - ethyl acetate - formic acid 14:7:1. Quantitative determination by absorbance measurement at 335 nm. In the stability test (stress conditions: acid, alkali, oxidation, dry heat, wet heat, photodegradation) the compound was well separated from degradation products. Linearity was in the range of 100 - 800 ng/spot.