J. Liq. Chromatogr. Relat. Technol. 30, 2209-2219 (2007). HPTLC of artemisinin in Artemisia annua on silica gel with cyclohexane - ethyl acetate - acetic acid 20:10:1 in a twin-trough chamber saturated for 20 min. Detection by immersion in modified anisaldehyde reagent (20 mL acetic acid, 4 mL sulfuric acid, 2 mL of anisaldehyde in a mixture of 100 mL ethanol and 80 mL water) for 1 s. After 1 min the plate was heated at 100 °C for 12 min. Quantitative determination by fluorescence measurement at 520 nm with cut-off filter at 540 nm.

J. Chromatogr. A 1112 (1-2), 156-164 (2006). HPTLC of glucosamine in a dietary supplement containing dried extracts of the main plants traditionally used for rheumatic disorders, on silica gel with a saturated mixture of 2-propanol - ethyl acetate - ammonia (8 %) 1:1:1. Detection by dipping into a modified anisaldehyde reagent and heating at 120 °C for 30 min in a drying oven. Quantitative determination by absorbance measurement at 415 nm. Validation of the method by applying the novel validation protocol proposed by a commission of the Société Française des Sciences et Techniques Pharmaceutiques. Relative standard deviations for repeatability and intermediate precision were between 4.9 and 8.6 %, accuracy was good, the two-sided 95 % beta-expectation tolerance interval was within the acceptance limits of 85 and 115 % on the whole analytical range (800 - 1200 ng of glucosamine).

J. Planar Chromatogr. 22, 197-200 (2009). HPTLC of whithaferin A on silica gel with toluene - ethyl acetate - formic acid 5:5:1 in a twin trough chamber saturated for 20 min at 25 +/- 2 °C and 50 +/- 5 % relative humidity. Detection under UV light and by dipping into freshly prepared p-anisaldehyde reagent, followed by heating at 110 °C for 10 min. Quantitative determination by absorbance measurement at 200 nm. The limit of detection and quantification was 100 and 800 ng/zone, respectively. The high sample throughput is useful for routine analysis of the preparation in industrial quality control and regulatory laboratories.

J. Chromatogr. A 1216 (11), 2150-2155 (2009). Chaihu roots (Bupleuri radix), roots of Bupleurum chinense and Bupleurum scorzonerifolium are monographed in the Chinese Pharmacopoeia. Evaluation of the quality of 33 lots of authenticated Chaihu samples versus 31 lots of commercial samples by HPLC-ELSD and HPTLC analysis of the principal bioactive components (saikosaponins). Data acquired from HPLC fingerprints and HPTLC fluorescent images was analyzed by chemometrics for similarity and pattern recognition, including artificial neural networks, k-nearest neighbor (k-NN) and an expert’s panel. The k-NN classifier showed good performance with sufficient flexibility for processing HPTLC fingerprint images. These images were otherwise not easily dealt with by other algorithms due to the shift of hRf values and varying hue/saturation of the band colors between different TLC plates. The two chromatographic fingerprint methods are complementary measures for quality control. Chaihu roots from different species of the genus Bupleurum could readily be distinguished from each other. Commercial samples of Chaihu can easily be classified by investigating the content of major saikosaponins.

J. AOAC Int. 92, 779-784 (2009). HPTLC of psoralen and plumbagin and extracts of ayurvedic polyherbal oil formulations on silica gel at 22 °C and 55 % humidity with toluene - ethyl acetate 3:1 in a twin trough chamber with chamber saturation. UV spectra were recorded from 200 to 600 nm; densitometric measurements were performed at 302 nm (for psoralen) and 275 nm (for plumbagin).

J. Chinese Trad. & Herb. Drugs 40 (8), 245-247 (2009). TLC of the TCM drug extracts on silica gel with 1) petroleum ether (90-120 °C) – toluene – formic acid 20:40:1; 2) chloroform – ethyl acetate – methanol – water – formic acid 3:10:2:2:2; 3) ethyl acetate – formic acid – water 12:2:3. Detection 1) by spraying with 10 % sulfuric acid in ethanol followed by heating at 105 °C; 2) by exposure to iodine vapor; 3) under UV 254 nm.

pruriens. Abstract No. 9425, IHCB (2009). HPTLC of L-dopa in Mucuna pruriens seed extract and formulations on silica gel with n-butanol - acetic acid - water 4:1:1. Quantitative determination by absorbance measurement at 280 nm. The method was linear in the range of 100-1200 ng/spot with an average recovery of 100.3 %.

Indian Drugs 46(6), 493-496 (2009). HPTLC of chloroform extracts of the bark of Ficus racemosa, F. bengalensis, and F. religiosa on silica gel with toluene - ethyl acetate - formic acid 90:10:1. Detection under UV 254 nm and visible light after treatment with vanillin sulfuric acid reagent, followed by heating at 105 °C until coloration.