Phytochem. Anal. 20, 421-426 (2009). HPTLC of delta-9-tetrahydrocannabinol in the flowertops of Cannabis sativa on silica gel with chloroform with chamber saturation for 20 min. Quantitative determination by absorbance measurement at 206 nm. Derivatization by dipping in Fast Blue B solution for 5 s. The hRf value of delta-9-tetrahydrocannabinol was 47 and selectivity regarding matrix was given. Linearity was given between 50 and 500 ng/zone. The limit of quantification and detection was 50 and 10 ng/zone, respectively. The intra- and inter-day repeatability (%RSD, n = 9) were not higher than 5.0 %. Recovery was 85.8 % for delta-9-tetrahydrocannabinol in decarboxylated Cannabis samples. The method was shown to be comparable within a small degree of error (0.5 %) to results from a validated HPLC method.

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 PA-192 (2008). HPTLC of strychnine and piperine in herbal extracts and herbal formulations on silica gel with toluene - ethyl acetate - diethyl amine 7:2:1. Quantitative determination by absorbance measurement at 283 nm. Linearity was 400-2000 ng/spot, recovery was in the range of 99.5-101.0 both for strychnine and piperine.

J. AOAC Int. 92, 1343-1348 (2009). HPTLC of beta-sitosterol, beta-amyrin and plant extracts on silica gel with chloroform - n-hexane - methanol 13:6:1. Detection by spraying with vanillin-orthophosphoric acid reagent, 5 % phosphomolybdic acid, or anisaldehyde reagent, followed by heating at 110 °C for 5 min. Vanillin reagent provided the best results. Quantitative determination by absorbance measurement at 525 nm.

J. Planar Chromatogr. 23, 50-55 (2010). HPTLC of andrographolide on silica gel with chloroform - methanol - ethyl acetate 12:3:2 in a twin-trough chamber previously saturated for 15 min. Quantitative determination by absorbance measurement at 223 nm. The relative standard deviation of intra-day and inter-day analysis was in the range of 0.56-1.33 %. Lineartiy was given between 200-700 ng/band; the correlation coefficient was 0.9998 and the RSD 0.97 %. The limits of detection and quantification were 60 and 150 ng/band. Average recovery was 98.8 +- 0.41 %.

J. Planar Chromatogr. 23, 112-115 (2010). HPTLC of phyllanthin on silica gel (prewashed with methanol) with hexane - toluene - ethyl acetate 2:2:1 in a twin-trough chamber saturated at 25-30 °C and 40-50 % relative humidity. Quantitative determination by absorbance measurement at 206 nm. LOD was 70 ng/mL, LOQ 200 ng/mL.The linear calibration range was 200-1200 ng/mL. Repeatability (RSD, n = 3) was 0.18-0.59 % with a correlation coefficient of 0.999. Intra-day and inter-day precision studies showed the CV was less than 2.0 %, indicating the method was precise: %RSD at 200, 600, and 1200 ng/mL was between 0.43 and 1.51 % for intra-day precision, and between 0.59 and 1.73 % for inter-day precision. The intra-day recovery for 200, 600 and 1200 ng/mL was between 102.3 % and 99.9 %, and the inter-day recovery between 102.5 % and 99.9 %, respectively.

J. Agric. Food Chem. 58, 4939-4944 (2010). HPTLC of azadirachtin (1) and salannin (2) in the seeds of Azadirachta indica on silica gel with hexane - ethyl acetate1:3. Quantitative determination by absorbance measurement at 220 nm. The hRf values of (1) and (2) were 18 and 30, respectively. Linearity was between 50 and 200 ppm for both (1) and (2). Recovery was 99.9 % for (1) and 99.3 % for (2). The intermediate precision was 88.5 % and 87.5 % for (1) and (2), respectively (n=3). The HPTLC and HPLC methods gave comparable results.

International Journal of ChemTech Research 1(4), 931-936, (2009). TLC of quercetin in hydroalcoholic extracts of dried flower of Nymphaea stellata (Nymphaceae). Separation on silica gel with toluene - ethyl acetate - formic acid 25:20:1. The hRf value was 26. Densitometric evaluation at 380 nm. The method was linear in the range of 20-200 ng/band. The average recovery was 99.3 %.