J .Chromatogr. Sci., 29, 423-427 (1991). HPTLC of sulfonamide on silica developed three times with mixtures of methanol, containing 2% NH3 (25%) and dichloromethane 3:7, 14:85 and 5:95. Detection by fluorescence quenching, or by spraying with a fluorescamine solution, and scanning by fluorescence at 366/>400 nm. Detection limit 0.32 ng. Limit of quantification, 4 µg/kg for milk and meat samples.

J. Planar Chromatogr. 5, 131-133 (1992). TLC of rhamnose, xylose, arabinose, mannose, glucose, galactose, glucuronic acid, galacturonic acid on silica impregnated with phosphate buffer (0.2M, pH 6.8) with acetonitrile - amyl alcohol - water 6:2:2. Detection by spraying with a solution of N-(1-naphthyl)ethylene diamine dihydrochloride (30 mg in 10 mL of a solution of 5 % sulfuric acid in methanol) followed by drying for 10 min at 100 °C. Quantification in the nanogram range by densitometry at 580 nm.

(Detection and identification of flunitrazepam (RohypnolR) in urine by TLC.) T+K 61 (3), 74-79, (1994). Sample preparation by acid hydrolysis followed by solid phase extraction (Extrelut); reduction of the nitro group by TiCl3. Chromatography on silica with chloroform - acetone - NH3 60:30:5, post chromatographic derivatization with Bratton-Marshall reagent; detection limit 100-150 ng/mL urine. Advantages over GC/MS: less interference by large concentrations of other drugs; low time requirement.

J. Pharm. Biomed. Anal. 34, 525-530 (2004). HPTLC of busulfan, an alkylating agent in pharmaceutical preparations, on Lichrospher silica gel with ethyl acetate - chloroform - methanol 13:4:3 in horizontal sandwich chamber. After development the plate was soaked in 2 % ethanolic solution of 4-nitro benzyl pyridine, followed by heating at 193 °C for 10 min. Quantitative determination by absorbance measurement at 600 nm. The method was validated for accuracy, precision, linearity (100-500 µg/mL), and specificity. The method was suitable for stability studies of busalfan in pharmaceutical preparations.

IPC 56th 2004, Abstract No. G-5. HPTLC of conessine in Holarrhena antidysentrica, an important ayurvedic drug, on silica gel with toluene - ethyl acetate - diethyl amine 13:5:2. Detection by spraying with Dragendroff’s reagent. Quantitative determination by densitometric scanning at 520 nm. Different market samples of the drug were found to contain 0.30 - 1.46 % of conessine with recovery of 95.18 - 102.70 %

J. Pharm. Biomed. Anal. 38, 180-185 (2005). A stability indicating HPTLC method is reported for estimation of cyclophosphamide in pharmaceutical preparations. HPTLC on silica gel with dichloromethane - methanol - acetic acid 97:3:2. Detection with alcoholic phosphomolybdic acid solution followed by heating at 190 °C for 10 min. Quantitative determination by absorbance measurement at 700 nm. Linearity was obtained between 0.40-1.20 mg/mL with recovery rates of 99.5 %. The method was validated for selectivity, specificity, accuracy, precision, and found to be stable for 28-70 days.

59th Indian Pharmaceutical Congress F-127, 420, (2007). HPTLC of citral (active constituent of cymbopogan citratus) on silica gel with toluene - ethyl acetate 17:3. Detection by spraying with vanillin-sulfuric acid reagent. Densitometric evaluation at 595 nm. The hRf value of citral was 55. Linearity was between 1 and 10 ng/zone. The citral content in cymbopolon citratus was found to be 67 - 81 %.

Anal. Chem. 74, 2653-2662 (2002). This review covers the literature of TLC/HPTLC found in Chemical Abstracts and ICI Web of Science from November 1, 1999 to November 1, 2001. Review Contents: 1. History, Student Experiments, Books, and Reviews; 2. Theory and Fundamental Studies; 3. Chromatographic Systems (Stationary and Mobile Phases); 4. Apparatus and Techniques; 5. Detection and Identification of Separated Zones; 6. Quantitative Analysis; 7. Preparative-Layer Chromatography and Thin-Layer Radiochromatography 8. Literature Cited.