J. Chinese Trad. & Herb. Drugs (Zhongcaoyao) 32 (8), 745-746 (2001). TLC on silica gel with butanol - chloroform - ethyl acetate 20:5:8. Detection by spraying with aceto anhydride - sulfuric acid 9:1 and heating at 110°C at 5 min. Identification by finger print technique, combined with UV spectra comparison, and microscopic characteristic.

J. Liq. Chrom. & Rel. Technol. 24, 1491-1499 (2001). TLC of glycyrrhetic acid, its monoglucuronide, and glycyrrhizin on silica gel with n-butanol - water - acetic acid 7:2:1. The developed plate was dried and then sprayed with a blotting solution mixture of isopropanol - methanol - water 1:4:20. It was placed on a stainless steel plate, then covered with a piece of PVDF membrane sheet. After covering with a glass microfiber filter sheet, the preparation was pressed evenly for 50 sec at 120°C on a hot plate. The PVDF membrane was separated from the TLC plate and dried. The blotted membrane was dipped in water containing sodium periodate and stirred at room temperature for 1 h.

J. Planar Chromatogr. 15, 244-251 (2002). TLC and HPTLC of alkylamides, phenylpropanoids and fructofuranosides from Echinacea species and common adulterants on silica gel (predeveloped with methanol and dried at 120°C). TLC of alkylamides with hexane - ethyl acetate 2: 1. Detection under UV 254 nm and, after derivatization with anisaldehyde reagent, in white light and at UV 366 nm. HPTLC of phenylpropanoids (e.g. caftaric acid, cynarin, chicoric acid, chlorogenic acid, caffeic acid, echinacoside) with ethyl acetate - ethyl methyl ketone - formic acid - water 5:3:1:1 with chamber saturation. Visualization under UV 366 nm after derivatization with natural products reagent (diphenylboric acid 2-aminoethylester). HPTLC of fructofuranosides with n-butanol - 2-propanol - water 1:3:1 without chamber saturation. Visualization by use of aniline-diphenylamine reagent. These HPTLC methods have been developed and peer verified in accordance with the AOAC guidelines.

Chinese J. Hosp. Pharm. (Zhongguo Yiyuan Yaoxue Zazhi) 23 (1), 31-32 (2003). TLC on silica gel with petroleum ether (60-90°C) - ethyl acetate 19:1. Detection under UV 365 nm. Quantitation by densitometry at 290 nm and with the standard addition calibration method.

J. Planar Chromatogr. 16, 396-401 (2003). HPTLC of gallic acid and tannin on cellulose with iso-butanol - acetic acid - water 14:1:3.5 and on silica gel with chloroform - ethanol - formic acid 5:4:1 in a saturated chamber. After drying visualization under UV light at 254 nm. Quantitation by densitometry at 280 nm in absorbance mode. The validated method was found to be simple, reliable, and convenient for routine analysis. Establishment of a validated procedure.

CBS 89, 4-7 (2002). HPTLC of devil’s claw extract on lichrospher silica gel with ethyl acetate - ethanol (70 %) 7:3 over 70 mm with chamber saturation. Detection by dipping in anisaldehyde - sulfuric acid reagent followed by heating at 105 °C until colors develop. Determination of bioactivity with DPPH-biotest by spraying with 0.05 % solution of (2,2-di-(4-tert-octylphenol)-1-picrylhydrazyl in methanol. Determination of antibiotic properties with Merck Chrom Biodip test by dipping in bacteria solution and incubation at 26 °C for 20 h, followed by spraying with yellow MTT tetrazolium salt.

J. AOAC Int. 86, 909-915 (2003). In quality control and stability testing of herbal medicinal products, fingerprint chomatograms are used as powerful tools to evaluate and compare the composition of compounds in such products. To fulfill the ICH- and GMP-based regulatory requirements in pharmaceutical QC, chromatographic fingerprint analysis needs to be validated. By considering the stationary phase, sample application, developing solvents, chromatogram development, plate labeling, derivatization, documentation, and chromatographic equipment the paper provides a comprehensive concept for evaluating validation parameters for planar chromatographic fingerprinting based on a standardized methodology. Validation parameters addressed include stability of the analyte, selectivity, robustness testing, and method reproducibility.

(Malvaceae). J. Planar Chromatogr. 18, 264-268 (2005). TLC in horizontal chambers of phenolic acids (caffeic, p-coumaric, ferulic, protocatechuic, gentisic, chlorogenic, isovanillic, gallic, syringic, vanillic and p-hydroxybenzoic acid) from Lavatera trimestris flowers on cellulose with water - acetic acid 3:17, toluene - ethyl formate - formic acid 5:4:1, chloroforrm - acetic acid - water 4:1:1 and of flavonoids (rutoside, kaempferol 3-rhamnoglucoside, hyperoside, isoquercetin, luteolin 7-glucoside, quercitrin, isorhamnetin 3-glucoside, luteolin, apigenin, quercetin, kaempferol) on silica gel with n-propanol - ethyl acetate - water 7:2:1, ethanol - 25 % ammonia - water 20:1:4, ethyl acetate - formic acid - water 10:2:3, ethyl acetate - formic acid - glacial acetic acid - water 100:11:11:27 and 50:5:5:9. Also two-dimensional TLC of phenolic acids on cellulose (after conditioning in the chamber for 5 min with benzene - methanol - acetic acid 94:1:5) with benzene - methanol - acetic acid - acetonitrile 16:2:1:1 in the first direction and with sodium formate - formic acid - water 1:0.1:20 in the second direction. Detection under UV light at 254 and 366 nm before and after treatment with ammonia vapor. Also derivatization by spraying with a 2 % aqueous solution of iron(III) chloride, diazotized sulfanilic acid in 20 % sodium carbonate solution, and diazotized p-nitroaniline for phenolics and with a 1 % methanolic solution of natural products reagent A for flavonoids.