J. Planar Chromatogr. 19, 238-240 (2006). HPTLC of plant extracts, using pellitorine and dihydropiperlongumine as markers, on silica gel in a twin-trough chamber saturated with the mobile phase hexane - ethyl acetate 3:1. Quantitation by densitometry in absorbance/reflectance mode at 260 nm.

J. Chromatogr. 264, 336-338 (1983). For forensic purposes, this TLC method for the clean-up of urinary extracts is an important step in isolating the metabolite. The elution for the TLC spot corresponding in Rf and Fast Blue B stain color to delta 9-THC-COOH provided an extract for gas chromatographic (GC)-mass-spectrometric (MS) determination. TLC of 11-nor- delta 9-tetrahydrocannabinol-9-carboxylic acid on silica with chloroform - methanol - NH3 70:30:2. Detection with Fast Blue B.

Phytochem. Analysis 17, 409-413 (2006). HPTLC of gymnemic acid as of gymnemagenin from callus cultures of Gymnema sylvestre on silica gel with chloroform – methanol 4:1. Quantitative determination by absorbance measurement at 205 nm. Linearity of determination of gymnemagenin is between 2 and 10 µg and its average percentage recovery from leave callus extracts is 98.6 - 99.2 %.

J. Chromatogr. 294, 431-435 (1984). TLC of methylparaben on silica with the solvent prepared by the organic layer of pentane - ether - water 70:30:100, shaked with 5 ml 85 % formic acid. Detection at 254 nm. Densitometry.

J. Liq. Chromatogr. Relat. Technol. 29, 1503-1514 (2006). TLC of tanshinones (cryptotanshinone, tanshinone I, tanshinone II A) on silica gel with light petroleum (60-90°C) - ethyl acetate 4:1. Evaluation and scanning densitometry at 280 nm. With TLC 8 stable components were separated in common within 48 min, respectively, from 3 crude samples of Salvia miltiorrhiza Bunge from different growth locations. With High Speed Countercurrent Chromatography (HSCCC) 12 components were separated, respectively, with good correspondence and precision within 13 h. Both TLCS and HSCCC were effective in showing the whole concentration distribution of all kinds of constituents in different samples. HSCCC showed better performance in analysis of tanshinones, which produced a fingerprint which contained more chemical information than that of TLCS.

Chem. Anal. (N.Y.), 85, 149-178, (1986). (Ultratrace Anal. Pharm., other Comp. Interest). A review with 55 references on sample preparation for ultratrace drug analysis in conventional, high-performance and reversed-phase TLC, type of plates and mobile phase selection, developing techniques.

J. Sep. Sci. 30, 1250-1254 (2007). HPTLC of Emblica officinalis extract on silica gel with ethyl acetate – formic acid – glacial acetic acid – water 10:1:1:2. Primary detection under UV 280 nm. Antiradical activity of individual components was estimated on intensity of disappearance of violet/purple background of plate after dipping in DPPH radical solution (0.5 mM in methanol) at room temperature for 90 s and that 30 s at 60 °C. Quantitative determination by absorbance measurement at 517 nm as negative peak. DPPH radical scavenging activity of emblicanins A and B was 7.9 and 11.2 times more active than that of ascorbic acid and 1.3 and 1.8 times more active than gallic acid, respectively.

People’s Hygiene Publishing House, Beijing 1990. A book with 222 pages and 186 drawings and photographs, introducing TLC densitometry and the related instrumentations, emphasizing on its applications in pharmaceutical analysis.