J. Planar Chromatogr. 19, 118-123 (2006). The computer-assisted simulation program DryLab has been used to simulate TLC separations. The simulations were based on data from preliminary TLC separations. For DryLab data entry of Rf values from TLC were converted to retention times, the development distance on the plate was used as column length, and the thickness of the adsorbent was used as the column diameter. To achieve reasonably accurated simulations it was found necessary to run three preliminary runs in which differences between organic modifier concentration in two adjacent runs were more than 5 %. The possibility of predicting HPLC separation conditions on the basis of TLC separations was also studied. - TLC of gallic acid, rutin, (+)-catechin, naringenin, and quercitin on RP18 with mixtures of acetonitrile and 0.1 % aqueous formic acid. Scanning at 255 nm in reflectance mode.

Indian Drugs 42 (10), 650-653 (2005). A simple rapid, precise and cost-effective HPTLC method has been developed for the determination of ursolic acid in Oscimum sanctum (Tulsi) leaves and its formulations (Tulsi ghan tablets and Tulsi capsules). HPTLC on silica gel with toluene - ethyl acetate - acetic acid 30:3:1. Detection with anisaldehyde in sulphuric acid reagent followed by heating in an oven at 110 °C. Quantitative determination by absorbance measurement at 580 nm. Linearity of the detector response was given in the range of 40 - 280 ng. LOD was 8 ng. The correlation coefficient obtained from linearity was 0.9985. The standard error was 26.511. The mean assay values of ursolic acid wa found to be 3.485 mg/g, 0.553 mg/g and 3.221 mg/g in tulsi ghan tablets, tulsi capsule and tulsi leaves respectively.

J. Chinese Trad. Patent Med. (Zhongchengyao) 27 (7), 854-856 (2005). TLC of chenodeoxycholic acid in Hedan tablets on silica gel with n-hexane - ethyl acetate - acetic acid - methanol 20:25:2:3. Detection by spraying with 10 % H2SO4 in ethanol followed by heating at 105 ºC until the spots are visualized. Quantification of chenodeoxycholic acid by densitometry at 375 nm. Validation of the procedure by investigation of its linearity range (0.47 - 2.33 µg/spot, R = 0.9992); of its repeatability (3.3 %, n = 5); of its precision (3.9 %, n = 5 within plate and 4.7 % n= 5 plate-to-plate); and its standard addition recovery (98.4%, RSD = 2.5 %, n = 5).

J. Planar Chromatogr. 19, 73-80 (2006). TLC of six atypical antipsychotic drugs (amisulpride, clozapine, olanzapine, quetiapine, risperidone, ziprasidone) on silica gel, amino, cyano, DIOL, and polyamide phases with mixtures of n-hexane and six polar modifiers (acetone, dioxane, diethylamine, ethanol, isopropanol, and tetrahydrofuran) in a horizontal DS chamber. After development the plates were inspected under UV light at 254 nm. Quantification by densitometry.

Acta Chrom. 9, 79-86 (1999). HPTLC of the primary carbohydrates in the planorbid snail Biomphalaria glabrata on silica gel CF254 with acetonitrile – water 17:3 and ethyl acetate – acetic acid – methanol – water 12:3:3:2, on LK5DF silica gel with ethyl acetate – acetic acid – methanol – water 12:3:3:2, on RP-18 with tetrahydrofuran – water 22:3, on cellulose with ethyl acetate – pyridine – water 2:1:2 and on amino-bonded layers with ethyl acetate – pyridine – water – acetic acid 12:6:2:1. The use of specific detection reagents for reducing sugars (4-aminobenzoic acid detection reagent and aniline – DPA reagent), spiking experiments, and spraying with alpha-naphthol – sulfuric acid reagent for quantitative analysis (densitometry at 515 nm) aided the identification of glucose and maltose. GC-MS analysis confirmed the identification of maltose and glucose on the basis of retention times and spectral fingerprints. A starvation study was conducted to determine changes in sugar levels in B. glabrata digestive gland–gonad complex (DGG) and hemolymph samples during a 12-day starvation period.

J. Planar Chromatogr. 19, 443-448 (2006). HPTLC of diclofenac sodium and paracetamol (with aceclofenac as internal standard) on silica gel, pre-washed with methanol, in a presaturated twin-trough chamber with toluene - ethyl acetate - methanol - formic acid 50:40:10:1. Quantitative determination by absorbance measurement at 260 nm. The method was validated regarding accuracy and precision.

J. Sep. Sci. 29, 2292-2295 (2006). HPTLC of 6-gingerol in the rhizomes of Zingiber officinale on silica gel with n-hexane – diethyl ether 2:3. Quantitative determination by absorbance measurement. Linearity of determination of 6-gingerol is between 250 and 1200 ng and its average percentage recovery is between 99.79 - 99.84 %. The method permits a good resolution and separation of other constituents of ginger.

Chromatographia 65 (3-4), 239-243 (2007). Description of a novel TLC densitometric method for the determination of solasodine in various Solanum species (Solanaceae). Solasodine does not show UV absorption therefore TLC of an ion pair complex of solasodine with an acid dye was performed. TLC plates developed by using a solvent with an organic acid ensured in situ color development of the complex. Densitometry at 461 nm. Linearity was 79.2 - 495 ng/zone, with a correlation coefficient of 0.995. The method shows good reproducibility, specificity and accuracy (98.54 ± 2.8%), and eliminates post derivatization steps and the problem of background interference. Validation of the method and application of the method to determine solasodine content in various herb samples, herb extract and their formulations, without matrix interference observed.