Indian Drugs 47(6), 59-61 (2010). HPTLC of gallic acid in bark powder of Terminalia crenulata (Combretaceae) on silica gel with toluene - ethyl acetate - formic acid - methanol 60:60:16:4 with chamber saturation for 30 min. Densitometric evaluation at 254 nm. The method was linear in the range of 200-1200 ng/band. Samples extracted with different solvents were compared. Both alcoholic and water extracts were found to contain gallic acid where as it was absent in the chloroform extract.

obtained by different techniques. J. Planar Chromatogr. 23, 320-322 (2010). HPTLC of thymol in Satureja hortensis L. extracts on silica gel with toluene - ethyl acetate 93:7. Detection by spraying with anisaldehyde reagent. Quantitative determination by absorbance measurement at 513 nm. The quantity of thymol extracted depends on the composition of the extraction solvent and the extraction technique. The best results were obtained by maceration with ethanol.

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.

62nd Indian Pharmaceutical Congress Abstract No. F-324 (2010). TLC of curcumin, piperine and quercetin in ayurvedic extract on silica gel with chloroform – toluene – ethyl acetate – methanol 4:4:1:1. The results obtained by the chromatographic method were comparable with a UV-VIS photometric method. All three compounds did not show any mutual interference.

Acta Chromatographica 20(4), 709-719 (2008). HPTLC of trigonelline and 4-hydroxyisoleucine from Fenugreek seeds (Trigonella foenum-graceum) on silica gel with n–butanol – methanol – acetic acid – water 8:3:2:2. Detection by spraying with ninhydrin reagent. Quantification by densitometry at 266 nm for trigonelline, and at 395 nm for 4-hydroxyisoleucine. The linearity was in the range of 100-1000 ng/band for trigonelline and 50-500 ng/band for 4-hydroxyisoleucine, respectively, with r=0.9992 and 0.9986 respectively. The average recovery at three different levels was 99.4 % for trigonelline and 99.1 % for 4-hydroxyisoleucine.

J. Sep. Sci. 34, 286-291 (2011). HPTLC of 1beta,3alpha,8beta-trihydroxy-pimara-15-ene (1), 6alpha,11,12,16-tertahydroxy-7-oxo-abieta-8,11,13-triene (2) and 2alpha,19-dihydroxy-primara-7,15-diene (3) in the root bark of Premna integrifolia on silica gel with hexane – acetone – ethyl acetate 3:1:1. Detection by dipping into vanillin-sulfuric acid reagent (2 g vanillin in 190 mL ethanol with 10 mL sulfuric acid) followed by air drying and heating for 3 min at 110 °C. Quantitative determination by absorbance measurement at 475 nm. The hRf values of (1), (2) and (3) were 58, 44, and 32, respectively and selectivity regarding matrix was given. Linearity was between 1-10 µg/spot for (1), (2) and (3), respectively. The limits of detection were found to be 230, 106 and 336 ng/band for compounds (1), (2) and (3), respectively, whereas the limits of quantification were 769, 354 and 1122 ng/band, respectively. Inter- and intraday precisions were 0.9-1.3 % and 1.1-1.2 %, respectively. The average recoveries for compounds (1) to (3) were found to be 100.6, 103.9 and 97.6 %, respectively, within the acceptable %RSD.

J. Planar Chromatogr. 24, 248-252 (2011). TLC of MGDG and DGDG on silica gel with chloroform - methanol -10 % acetic acid 40:10:1. Detection by spraying with a 25 % solution of sulfuric acid in methanol, followed by heating at 105 °C for 5 min. Quantitative determination by densitometry at 477 nm. The hRf values were 48 for DGDG and 80 for MGDG. The limit of detection and quantification was 200 and 500 ng/band for DGDG and 500 and 1500 ng/band for MGDG. The linear range was 0.5-5.5 µg/band for DGDG and 1.5-5.5 µg/band for MGDG, respectively. The recovery (n= 9) was 95.7 % for DGDG and 93.5 % for MGDG. The repeatability and intermediate precision of results, as %RSD, was between 1.7-2.7 % for DGDG and 1.7-2.6 % for MGDG.

J. Planar Chromatogr. 24, 121-124 (2011). HPTLC of kurarinone and sophoraflavanone G in the roots of Sophora flavescens on silica gel with chloroform - methanol 10:1 with chamber saturation for 30 min at 20 °C. Quantitative determination by absorbance measurement at 285 nm. The intra-day and inter-day %RSD were 1.9-2.0 % and 2.2-2.4 %, respectively. Instrument precision and repeatability of the method were 0.4-0.6 and 1.81-1.84 %, respectively. Average recovery was 96.3-103.4 % for kuraninone and 96.8-102.9 % for sophoraflavanone G. The limits of detection and quantification were 27 and 80 ng/band for kurarinone and 12 and 36 ng/band for sophoraflavanone G. Linearity was in the range of 200-1200 ng/band for kurarinone and 90-550 ng/band for sophoraflavanone. The hRf value was 31 and 50 for kurarinone and sophoraflavanone, respectively.