J. Liquid Chromatogr. 18, 1663-1670 (1995). Preparative scale separation of the title compounds by centrifugal partition chromatography (CPC). Determination of the composition of the fractions by TLC on cellulose with 1-butanol - acetic acid - water 122:21:57. Identification by 1H NMR.

Analyst 119, 2655-2658 (1994). TLC of 40 hormones on silica with chloroform - acetone 9:1, and cyclohexane - ethyl acetate - methanol 117:78:11. Detection by spraying with 10% sulfuric acid in methanol and heating at 95 °C for 10 min. Visualization under UV 366 nm. Detection limit were given. The method enables screening of 39 hormones illegally injected.

Phytochemistry 42, 513-522 (1996). TLC of forty different bufadienolides on silica with chloroform - methanol - water 140:44:7, ethyl acetate - methanol - water 81:11:8 or MEK- toluene - water - methanol - acetic acid 80:10:6:5:2. Also HPTLC on RP-2 with methanol - water 1:1. Detection with 50 % ethanolic sulfuric acid at 105 °C.

by thin-layer chromatography.) (Chinese). J. Chinese Trad. Patent Med. (Zhongchengyao) 17 (9), 16-17 (1995). TLC of ginsenosides on silica with 1) chloroform - ethyl acetate - methanol - water 15:40:22:10; 2) chloroform - methanol - water 13:7:2. Detection by spraying with 10 % sulfuric acid in ethanol and heating at 110 °C for 5-10 min and under UV 365 nm. Discussion of the quality control of the drugs by TLC.

J. Planar Chromatogr. 9, 39-47 (1996). HPTLC of 30 preservatives on silica, RP-18, CN, diol with 5 different mobile phases; detection with nine different methods. The procedure based on hRf values and color codes can be used for the detection and identification of the preservatives after being entered into a user-generated data base. The data compilations comprise the retention values obtained after chromatography using 5 different chromatographic systems (adsorption, partition, and reversed phase) and the colors obtained upon spraying with selected reagents, the color codes being read by the user from a color key card. By combination of more than two chromatographic systems, identification of unknown samples becomes reliable.

J. Planar Chromatogr. 9, 280-281 (1996). HPTLC of heroin, opium, mandrax tabl., diazepam, oxazepam, nitrazepam, phenobarbitone, and caffeine on silica with chloroform - ethanol 9:1. Detection after drying for 5 min at 100°C by spraying with a 1:1 mixture of 1% aqueous solutions of cupric chloride and potassium ferricyanide resulting in a dark brown spot for heroin. The reagent does not give positive reaction to the usually occurring adulterants as barbiturates, benzodiazepines, methaqualone, and caffeine, etc. Sensitivity: about 1 mg of heroin/spot.

Phytochemistry 48, 991-994 (1998). TLC of numerous methoxyflavone aglycones on polyamide DC6 with toluene - methyl ethyl ketone - methanol 4:3:3 and with toluene - petroleum ether - methyl ethyl ketone 60:26:7. Detection under UV 254 and 366 nm. Rf values and spectral properties of 17 different aglycones are given.

The effect of pH. J. Planar Chromatogr. 11, 64-69 (1998). Determination of the lipophilicity and specific hydrophobic surface area of 21 fused-ring nitrogen heterocycles by RPTLC and study of the effect of different mobile-phase additives such as acetic acid, sodium acetate, and lithium chloride on the retention. Regular retention behavior was observed for each solute, the RM value decreasing linearly with increasing concentration of acetonitrile in the mobile phase. RPTLC of 21 nitrogen containing heterocycles on silica gel impregnated with paraffin oil. Detection after drying at 105°C under UV and by exposure to iodine vapor.