Asian Journal of Chemistry 23(1), 385-387 (2011). HPTLC on silica gel with chloroform - ethyl acetate containing 1 % acetic acid. Two well resolved zones with hRf values of 33 and 55 were obtained by illumination at 254 nm. The zones were labelled as substance I and II and used for standardization of the oil. Densitometric evaluation at 265 nm. The linearity range for both substances was 4-100 µg/band. The recovery was in the range of 97.4-98.7 %. Several commercially available tablets and capsules were analyzed for the content of Neem oil using substances I and II as marker (in the absence of chemical markers).

62nd Indian Pharmaceutical Congress Abstract No. F-259 (2010). Health drinks usually contain several phytopharmaceuticals with immunomodulatory and antioxidant activities. TLC of gallic acid on silica gel with toluene – ethyl acetate – methanol – formic acid 15:15:1:4. The gallic acid content was established and the identity of the gallic acid zone in sample and standard was confirmed by UV spectra comparison.

Acta Chromatographica 22 (2), 259-265 (2010), DOI:10.1556/AChrom.22.2010.2.8. Description of a new, simple, precise, and accurate method for quantification of (-)-epicatechin in the leaves of Cassia fistula by HPTLC on silica gel with toluene – ethyl acetate – formic acid – methanol 205:3:1:1. Quantification by densitometry at 280 nm. The linearity was in the range of 200–800 ng/band. Method precision was 1.4 %RSD and instrumental precision 1.1 %RSD. Recovery was 98.1 % and specificity regarding matrix was given.

J. Ethnopharmacol. 139, 142-148 (2012). HPTLC of 1,2-dihydroxy-3-pentadec-8-enylbenzene (A) and 1,2-dihydroxy-3-pentadeca-8,11-dienylbenzene (B) in the fruits of Semecarpus anacardium L. f. (Anacardiaceae) on RP-18 with acetonitrile - water 199:1. Detection by spraying with anisaldehyde - sulfuric acid reagent. The hRf values of (A) and (B) were 31 and 42, respectively. The method was combined with ESI-MS and NMR for compound identification.

and Gentianella acuta by thin-layer chromatography) (Chinese). J. of Inner Mongolia Univ. for Nationalities (Natural Sci. Edit.) 26(1), 71-72 (2011). TLC of the extracts of the title medicinal herbs on silica gel with 1) chloroform - methanol - water - formic acid 28:2:2:1, detection by spraying with 10 % sulfuric acid in ethanol and heating at 105 °C until the zones were detected; 2) chloroform - methanol - ammonia 40:10:1, detection by spraying with iodine solution. Identification by comparison of the fingerprint with the main components gentianine, isoorientin, flavone, isobellidifolin, swerchirin, and 1,5,8-trihydroxy-3,4-dimethoxyxanthone.

J. Planar Chromatogr. 24, 497-502 (2011). HPTLC of isoswertisin-5-O-beta-D-glucoside (1), swertiamarin (2), and swertisin (3) as biomarkers on silica gel with ethyl acetate - methanol - water 16:2:1 in a twin-trough chamber with saturation for 30 min. Quantitative determination by absorbance measurement at 287 nm. Linearity was between 25-75 µg/mL for (1), 200-600 µg/mL for (2), and 100-300 µg/mL for (3). The relative standard deviation for instrumental precision, intra-assay precision, and intermediate precision was below 2 %. The average recovery was 99.9 % for (1), 99.6 % for (2), and 99.1 % for (3). The hRf values were 32 for (1), 41 for (2), and 52 for (3). The limit of detection was 570 ng, 740 ng, and 300 ng for (1), (2), and (3), respectively.

J. of Chromatogr. Sci. 49, 560-567 (2011). Evaluation of the fingerprinting efficiency of a novel two-dimensional analytical system composed of RP-TLC and RP-LC-MS. The efficiency of the system was compared with that of the one-dimensional system RP-TLC with MS detection. The test samples were phenolic acid extracts from Salvia lavandulifolia. Both systems can be applied to the fingerprint analysis of herbal extracts, but the two-dimensional system based on RP-TLC and RP-LC-MS can provide more abundant information.

Asian Journal of Chemistry 23 (5), 2098-2100 (2011). HPTLC of glycyrrhizic acid in herbal formulation on silica gel with chloroform - glacial acetic acid - methanol - water 15:8:3:2. The hRf value of glycyrrhizic acid was 28. Quantitative evaluation by absorbance measurement at 254 nm. The method was found to be linear in the range of 100-500 ng/band with average recovery between 99-102 %.