J. AOAC Int. 99, 1204-1212 (2016). HPTLC of St. John’s wort labeled as Hypericum perforatum on silica gel with ethyl acetate – dichloromethane – formic acid – acetic acid – water 100:25:10:10:11 (USP 38-NF33), ethyl acetate – formic acid – water 30:2:3 (European Pharmacopoeia) and ethyl acetate – acetic acid – formic acid – water 100:11:11:26 (USP 37-NF32). For the investigation of synthetic dyes, samples were analyzed on RP-18 with methanol – 5 % aqueous sodium sulfate 3:4. Detection by dipping into natural products reagent (1 g diphenylborinic acid 2-aminoethylester in 200 mL ethyl acetate), then in polyethylene glycol reagent (10 g PEG 400 (macrogol) in 200 mL dichloromethane). Qualitative identification under UV 254 and 366 nm. A decision tree was developed to analyze adulterated samples labeled as Hypericum perforatum. If for example under UV 366 nm after derivatization a yellow fluorescent zone is seen at hRF 46, samples are probably mixed with another undesired species. In addition, if a bluish zone is seen at application position of samples identified with the test USP 38-NF32 and examined under white light prior derivatization, the sample is probably mixed with dyes.

Planta Medica 83(14/15), 1176-1183 (2017). The fractionation on cyclodextrane with methanol – water 9:1 of the acetone macerate of Crocus sativus flowers (without stigma) was analyzed by TLC on silica gel with ethyl acetate – acetic acid – formic acid – water 100:11:11:26. Detection under UV light and after derivatization with natural products reagent (1 % in methanol), followed by 5 % ethanolic PEG solution. The 182 fractions were pooled into 8 fractions, whereby fraction 2 contained pure kaempferol-3-O-sophoroside (its structure and 98 % purity were confirmed by NMR). The yield was 1.4 % of the dried flowers._x000D_

of Pharm.(Yaoxue Xuebao) 20, 59-66 (1985). (Chinese). (HPLC and TLC determination of alkaloid constituents in sophara flavescens and saphora lopecuroides.) TLC of sophocarpine, matrine, sophoridine, oxymatrine and oxysophocarpine on silica with benzene - acetone - methanol 8:3:0.5. Determination by densitometry at 510 nm. Comparison with HPLC results (good agreement).

Evaluation of the constituents and quality.) HPTLC of tetrahydrocoptisine, alpha-corydaline, DL-tetrahydropalmatine, protopine, coptisine, palmatine and glaucine on silica with various developing systems.

by thin-layer chromatography.) TLC of hyperoside on silica with ethyl acetate - butanol - formic acid - water 5:3:1:1, or on polyamide with chloroform - methanol - water 4:1.5:0.1. Detection by spraying with 1 % aluminium chloride. Elution with methanol - water - ethyl acetate 1.5:1:1. Quantification by pulse polarography.

J. Chromatogr. 369, 435-439 (1986). TLC examination of phorbol on silica with 10 different solvent systems, and on long-chain-hydrocarbon-bonded silica with 4 different combinations of methanol - acetonitrile -water. Detection under UV at 254 nm and by spraying with vanillin - sulfuric acid -ethanol 3:0.5:100 and heating at120 °C.

(Determination and differentation of the essential ingredients in hops with TLC, HPTLC and IR.) MERCK Spectrum 1, 54-56 (1988). TLC of humulon, lupulon, xanthohumol and chlorophyll on silica with cyclohexane - ethyl acetate - propionic acid 60:38:2. Detection under UV at 365 nm.

Optimization of TLC/HPTLC of ginsenosides. H. TRAITLER, A. STUDER, R.E. KAISER (eds): Instrumental HPTLC, Institute for Chromatography, Bad Dürkheim, FRG (1987), 401-413. TLC/HPTLC on silica with chloroform - ethyl acetate - methanol - water 15:40:22:10. Visualization by dipping in 5% sulfuric acid - ethanol. Detection by fluorodensitometry. Discussion of the optimization of chromatographic conditions.