J. Planar Chromatogr. 20, 73-74 (2007). HPTLC of hedychenone (a trimethyldecalin terpene) on silica gel with n-hexane - ethyl acetate 4:1 in a saturated twin-trough chamber. After development the plates were dried at 105 °C for 20 min. Densitometric evaluation in absorbance mode at 254 nm.

J. Chromatogr. Sci. 46 (6), 560-564 (2008). Quantitative TLC is performed with a digital imaging system with simple equipment and software. The method was used for the quantitative assay of cichoric acid in Echinacea purpurea. TLC on polyamide phase with chloroform - methanol - formic acid - water 3:6:1:1. Detection by spraying with 3 % aqueous aluminum chloride solution. Images of chromatograms were acquired with a standard digital camera under a UV lamp at 365 nm in a dark room. The three-dimensional grayscale digital image dataset (x, y, gray) was reduced to a two-dimensional dataset (distance, accumulative gray) and then plotted as a curve. For quantification the area under the curve (corresponding to cichoric acid) was integrated.

Chromatographia 67 (5-6), 487-490 (2008). Simultaneous determination of escitalopram oxalate and clonazepam in a combined tablet dosage form by HPTLC on silica gel aluminum plates with toluene - ethyl acetate - triethylamine 14:7:6. Quantification by densitometry at 258 nm.

J. of Pharm. Biomed. Anal. 44 (3), 812-817 (2007). HPTLC of extracts of Notopterygium incisum Ting ex H.T. Chang (or Notopterygium forbesii Boiss) root and rhizome, and marker compounds isoimperatorin, notopterol and bergapten. The authentication of rhizoma et radix Notopterygii was achieved by comparing the colors and Rf values of the bands in TLC fingerprints with those of the marker compounds. The HPLC fingerprints of 16 batches of herbal samples from different regions of China showed similar chromatographic patterns. Five peaks were selected as characteristic peaks, and three of these were identified by using LC-MS-MS techniques.

Microbiol. Res. 163, 307-313 (2008). HPTLC of norharmane from cyanobacterial culture medium extracts on silica gel with ethyl acetate - methanol - water 200:33:27 or ethyl acetate - formic acid - water 20:2:1. The hRf values of norharmane were 65 and 20, respectively. Evaluation under UV 254 nm without further derivatization. The screening of microalgal culture medium was performed by HPTLC and HPLC.

Part II. Nicotinic acid and its esters. J. Liq. Chromatogr. Relat. Technol. 30, 2419-2433 (2007). TLC and HPTLC of nicotinic acid and methyl nicotinate, ethyl nicotinate, isopropyl nicotinate, butyl nicotinate, and benzyl nicotinate on RP-18 (prewashed with methanol) with methanol - water and dioxane - water in 10 % volume ratio steps from 100:0 to 0:100 in a chamber saturated for 30 min. TLC on aluminium oxide (prewashed with methanol) with acetone - n-hexane 1:4 provided the optimum conditions for complete separation. Quantitative determination by absorbance measurement at 254 nm.

Asian J. Chem. 20(7), 5409 - 5413 (2008). HPTLC of atomoxetine HCl on silica gel with acetonitrile - acetic acid 9:1. Quantitative determination by absorbance measurement at 269 nm. The method was linear in the range of 100-1000 µg/mL. The recovery was 99.8 %. The method was suitable for routine analysis of atomoxetine HCl in its pharmaceutical preparations.

J. Sep. Sci. 31, 3537-3542 (2008). After solid phase extraction of water samples HPTLC of clofentezine (1), neburon (2), chlorfenvinphos (3), lenacyl (4), trifluralin (5), thiram (6), procymidone (7), flufenoxuron (8), tralkoxydim (9), propaquizafop (10), and dinoseb (11) on silica gel with ethyl acetate – n-heptane 2:8, 3:7, 4:6, or 7:3 as mobile phase. Quantitative determination by absorbance measurement between 200 and 600 nm. Selectivity regarding matrix was given. Linearity was 0.1-1.5 µg/spot for (1), 0.2-1.0 µg/spot for (2), 0.5-1.0 µg/spot for (3), 0.2-1.0 µg/spot for (4), 0.3-9.0 µg/spot for (5), 0.2-1.0 µg/spot for (6), 2.0-11.0 µg/spot for (7), 0.1-2.0 µg/spot for (8), 0.3-1.0 µg/spot for (9), 0.1-1.0 µg/spot for (10), and 0.2-1.0 µg/spot for (11). The limits of detection and quantification were 0.23 and 0.70 µg/spot for (1), 0.06 and 0.18 µg/spot for (2), 0.16 and 0.49 µg/spot for (3), 0.04 and 0.12 µg/spot for (4), 0.06 and 0.18 µg/spot for (5), 0.16 and 0.49 µg/spot for (6), 0.65 and 1.92 µg/spot for (7), 0.10 and 0.31 µg/spot for (8), 0.07 and 0.22 µg/spot for (9), 0.06 and 0.17 µg/spot for (10), and 0.08 and 0.24 µg/spot for (11). The optimal wavelenght for quantification was 278 nm for (1), 249 nm for (2), 247 nm for (3), 273 nm for (4), 277 nm for (5), 281 nm for (6), 208 nm for (7), 268 nm for (8), 284 nm for (9), 245 nm for (10), and 366 nm for (11). Advantages of the technique over the HPLC method are highlighted.