J. AOAC Int. 92, 410-418 (2009). HPTLC of agrimoniin, pedunculagin, ellagic acid, gallic acid and catechin and plant extracts on silica gel, RP-18 and amino phase in a horizontal chamber. The best resolution and selectivity were achieved with diisopropyl ether - acetone - formic acid - water 4:3:2:1, tetrahydrofuran - acetonitrile - water 3:1:6, and acetone - formic acid 3:2. Polyphenols were detected under UV light at 254 nm and in visible light after spraying with 1 % methanolic iron(III) chloride or bis-diazotized sulfanilamide and after treatment with a vanillin-hydrochloric acid reagent.

using supercritical carbon dioxide. J. AOAC Int. 92, 103-110 (2009). Analytical and preparative TLC of aucubin and herbal extracts after extracton with supercritical carbon dioxide on silica gel with methanol - chloroform - petroleum ether - ethyl acetate 1:3:3:1. Visualization by spraying with 30 % sulfuric acid.

60th Indian Pharmaceutical Congress PG-246 (2008). HPTLC of biomarkers such as curcumin, charantin, and swertiamarin in some polyherbal formulations on silica gel with benzene - methanol 4:1 (for charantin), chloroform - methanol - formic acid 74:4:1 (for curcumin), and ethyl acetate - methanol - water 77:15:5 (for swertiamarin). Quantitative determination by absorbance measurement at 536 for charantin (hRf value 33), 425 nm for curcumin (hRf value 89), and 238 nm for swertiamarin (hRf value 54).

J. Planar Chromatogr. 22, 297-300 (2009). HPTLC of chlorogenic acid and of plant extracts on silica gel with ethyl acetate - formic acid - water 10:2:3 and ethyl acetate - formic acid - acetic acid - water 100:11:11:21 in a saturated horizontal chamber. Quantitative determination by absorbance measurement at 320 nm. Qualitative detection by derivatization with natural products reagent (1 % in methanol) followed by treatment with 5 % PEG 400 in ethanol.

Abstract No. C-372, 61st IPC (2009). HPTLC of withanolide A in extracts and spansules dosage form on silica gel with toluene - ethyl acetate - formic acid 8:6:1. Densitometric evaluation at 254 nm. Withanolide A was well separated with an hRf value of 14. The linearity range was 40-200 ng/band.

Ind. J. Pharma. Science 71 61, 656-662 (2009). Medicated oils prepared both by Ayurvedic as well as modified process were evaluated for fingerprint profiling by HPLC and HPTLC. HPTLC of methanolic extracts of the oils on silica gel with chloroform methanol 9:1 and toluene - ethyl acetate 4:1 for general fingerprint profiling; with toluene - ethyl acetate - formic acid 5:4:1 for flavonoids and with toluene - ethyl acetate - diethyl amine 7:2:1 for alkaloids. Evaluation under 254 nm and 365 nm. Detection by treatment with NP-PEG reagent for flavonoids and Dragendorff reagent for alkaloids.

J. Planar Chromatogr. 23, 70-74 (2010). Descripton of a selective and simple HPTLC method for quantification of oenothein B on the basis of the free gallic acid and total gallic acid content after acid hydrolysis. HPTLC of gallic acid on silica gel with benzene - methanol - acetic acid 90:16:8 in a glass chamber previously saturated with the mobile phase vapor for 20 min. Quantitative determination by absorbance measurement at 570 nm after derivatization with 1 % ethanolic iron(III) chloride solution. Average recovery of the active ingredient was in the range 95.4-104.6 %. Linearity was in the range of 440-2200 ng/band. The correlation coefficient r was 0.9991, LOD/LOQ were120/360 ng/band; repeatability (RSD) was 3.0 % and intermediate precision 1.0 %; intraday precision (RSD, n = 6, 440-2200 ng/band) was 3.8 to 5.2 % and interday precision 4.3 to 5.7 %. Both, precision and accuracy, were within acceptable limits for routine drug analysis (</= 15 %).

using central composite design. Phytochem. Anal. 21, 544-549 (2010). HPTLC of withaferin A in the aerial part of Withania somnifera Dunal. on silica gel with ethyl acetate - toluene - formic acid - 2-propanol 14:4:1:1. Quantitative determination by absorbance measurement at 220 nm. The hRf of withaferin A was 29. Detection and quantification limits were 18 and 60 ng/zone respectively. The intra-day and inter-day precisions were 4.24 % and 14.28 %, respectively. Recovery (by standard addition) was 88.2 %.The correlation coefficient of the withaferin A determination was 0.9963.