J. Planar Chromatogr. 20, 135-138 (2007). HPTLC of eugenol (4-allyl-2-methoxyphenol) on silica gel prewashed with methanol in a twin-trough chamber saturated for 20 min with toluene - ethyl acetate - formic acid 93:7:1.4). Quantitation by scanning at 289 nm.

59th Indian Pharmaceutical Congress C-17, 228 (2007). HPTLC of curcumin, charantin, and swetiamarin in polyherbal formulations on silica gel with benzene - methanol 4:1 for charantin, chloroform - methanol - formic acid 74:4:1 for curcumin, and ethyl acetate - methanol - water 77:15:5 for swetiamarin. Densitometry at 536 nm for charantin, 425 nm for curcumin, and 238 nm for swetiamarin. The hRf values were 33, 89, and 54 for charantin, curcumin, and swertiamarin respectively.

CBS 97, 12-15 (2006). HPTLC of flavonoids from green tea (Camellia sinensis) on silica gel in a saturated twin-trough chamber with ethyl formate - toluene - formic acid - water 60:3:8:6. Detection by dipping the hot plate (heated at 100 °C for 2 min) into natural products reagent, followed by drying, dipping into polyethylene glycol 400 (10 g in 200 mL dichloromethane), and drying. Evaluation under UV 366 nm. With this method the geographical origin of the material can be determined. Toluene - acetone - formic acid 9:9:2 allows the discrimination of green from black and other speciality teas, based on the polyphenol pattern. Detection by dipping the hot plate into a solution of Fast Blue Salt B. Evaluation under white light. For investigation of the alkaloid profile ethyl acetate - methanol - water 20:2.7:2 and evaluation under UV 254 nm is used. The amino acid profile is analyzed by using 1-butanol - acetone - acetic acid - water 7:7:2:4. Detection by dipping in ninhydrin reagent, followed by heating at 110 °C for 3 min. Evaluation under white light.

J. Planar Chromatogr. 20, 73-74 (2007). HPTLC of hedychenone (a trimethyldecalin terpene) on silica gel with n-hexane - ethyl acetate 4:1 in a saturated twin-trough chamber. After development the plates were dried at 105 °C for 20 min. Densitometric evaluation in absorbance mode at 254 nm.

J. Chromatogr. Sci. 46 (6), 565-573 (2008). Investigation of selected amino acid standards on cellulose layers using organic-aqueous eluent systems modified with neutral and chaotropic salts: chlorides, iodides, nitrates, thiocyanates, perchlorates, and hexafluorophosphates at low concentrations from 10 to 80 mM in the mobile phase. The effect of salts used as mobile phase modifiers was evaluated by comparison of densitograms, peak symmetry coefficients, and theoretical plate numbers. The efficiency of the investigated chromatographic systems depends primarily on the kind of salt and organic solvent in the mobile phase. The best efficiency was obtained by adding ammonium thiocyanate to the mobile phase which contained acetonitrile as an organic modifier.

J. Planar Chromatogr. 21, 177-181 (2008). TLC of azithromycin on silica gel with chloroform - ethanol - ammonia 30:70:1. Detection by spraying with sulfuric acid - ethanol 1:4 followed by heating at 120 °C for 5 min. Quantitation by densitometry at 483 nm.

J. AOAC Int. 91, 268-275 (2008). HPTLC of actein, 23-epi-26-deoxyactein, cimiracemoside, cimifugoside, caffeine, and tyrosine as standards on silica gel (prewashed with methanol) with toluene - ethyl formate - formic acid 5:3:2 in a saturated chamber. Detection under UV 254 and 365 nm, under white light after spraying with anisaldehyde reagent, and via the Bioluminex assay. For the Bioluminex assay the developed and dried HPTLC plate was coated with a buffered solution of luminescent Vibrio fischeri. Documentation of luminescent and inhibited zones with a CCD camera.

J. Sep. Sci. 31, 47-55 (2008). HPTLC of phyllanthin (1), hypophyllanthin (2), niranthin (3), and nirtetralin (4) in the leaves of four Phyllanthus species, P. amarus, P. maderaspatensis, P. urinaria, and P. virgatus, on a chiral TLC plate with n-hexane - acetone - 1,4-dioxane 18:2:1. Detection by dipping in vanillin reagent (1 g vanillin, 5 mL sulphuric acid, 95 mL ethanol) followed by heating at 110 °C for 15 min. Quantitative determination by absorbance measurement at 620 nm. The hRf values were 30, 36, 41, and 48 for (1) to (4), respectively. Linearity was between 100 and 500 ng/band and the recoveries for (1) to (4) were 99.9, 100.5, 99.2, 98.7 %, respectively. The limit of detection and quantification was 26 and 88, 45 and 136, 53 and 176, and 57 and 187 ng/band for (1) to (4), respectively. No significant intra- and interday variation was observed.