by TLC. Chromatographia 66 (7-8), 631-634 (2007). TLC of heraclenin and heraclenol in the roots of Heracleum candicans D.C. on silica gel with toluene - ethyl acetate 7:3. Quantitative determination by densitometry at 366 nmn. Linearity was between 4 - 10 µg/zone for heraclenin and 1 - 5 µg/zone for heraclenol.

J. AOAC Int. 91, 339-343 (2008). HPTLC of conessine on silica gel (prewashed with methanol) with toluene - ethyl acetate - dimethylamine 13:5:2 in a saturated twin-trough chamber. Detection by spraying with Dragendorff reagent, followed by spraying with a 10 % solution of aqueous sodium nitrite. Quantitative determination by densitometry at 520 nm. Linearity was between 10 and 60 ng/spot. The limit of detection was 3 ng/spot.

J. AOAC Int. 91, 1179-1185 (2008). HPTLC of harmine, harmaline, vasicine, and vasicinone on silica gel with ethyl acetate - methanol - ammonia 70:10:3 in a twin-trough chamber at 25 °C and 40 % relative humidity. Quantitative determination by absorbance measurement at 366 nm for harmine and harmaline, at 292 nm for vasicine, and at 233 nm for vasicinone.

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.

60th Indian Pharmaceutical Congress PA-217 (2008). HPTLC of oleanolic acid in total methanolic extract of fruits of Randia dumetorum lam. on silica gel with toluene - ethyl acetate - acetic acid 70:30:1 in a twin trough chamber saturated for 10 min. Detection by treatment with 10 % sulphuric acid in methanol, followed by heating at 110 °C and immediate densitometric evaluation. Quantitative determination by absorbance measurement at 540 nm. The method was linear in the range of 50-500 ng/spot. Recovery was in the range of 99.4-100.8 %.

J. Chinese Pharm. Standard 10 (4), 284-286 (2009). TLC of Naolibao pill extracts on silica with n-hexane - ethyl acetate 5:1. Qualitative identification by detection under UV 254 nm and 365 nm. The method is simple, rapid, reliable, and suitable for the quality control of the TCM formulation.

J. Sep. Sci. 32, 3239-3245 (2009). HPTLC of shikonin (1), acetylshikonin (2), and beta-acetoxyisovalerylshikonin (3) in four species of Arnebia on RP-18 with acetonitrile - methanol - 5 % formic acid 20:1:4. Quantitative determination by absorbance measurement at 520 nm. Linearity was in the range of 100-600 ng/zone for (1) and (2) and 100-1800 ng/zone for (3). The limits of detection for (1), (2) and (3) were 18, 15 and 12 ng/zone, respectively, while the limits of quantification were 60, 45 and 40 ng/zone, respectively.

J. AOAC Int. 93, 1617-1621 (2010). HPTLC of aconitine on silica gel with ethyl acetate - ethanol 3:1 at 22 °C in a saturated twin-trough chamber. The hRf value of aconitine was 33. Quantitative determination by absorption measurement at 238 nm. LOD and LOQ was 20 and 70 ng/band, respectively. The linearity with respect to peak area was in the range of 300 to 1800 ng/band with an r of 0.9991. The repeatability (RSD) was 0.85 %; and the inter-day and intra-day precision (RSD) was 1.01-1.38 and 1.04-1.34 %, respectively.