Food Chem. 121, 185-190 (2010). TLC of arbutin in the leaves and flowers of Origanum majorana and Origanum vulgare on silica gel with ethyl acetate - methanol - water 77:13:10. Detection by spraying with 2.5 % dibromchinochlorimide solution in ethanol. The hRf of arbutin was 47.

CBS 104, 2-4 (2010). HPTLC of beta-boswellic acid (BA), acetyl-beta-boswellic acid (ABA), 11-keto-beta-boswellic acid (KBA), and acetyl-11-keto-beta-boswellic acid (AKBA) in Boswellia serrata extracts on silica gel with n-hexane - ethyl acetate - glacial acetic acid 16:5:1 in a twin-trough chamber saturated for 15 min. Quantitative determination by absorption measurement at 254 nm for KBA and AKBA, and at 560 nm for BA and ABA after derivatization by manual dipping in anisaldehyde reagent follwed by heating at 110 °C for 5 min. Results were compared with results from the HPLC analysis. By HPLC (injection volume 20 µL) the limits of detection for KBA and AKBA were 6-8 ng, and for BA and ABA 60-80 ng. By HPTLC (application volume 2 µL) the limits of detection for KBA and AKBA were 150 ng, and for BA and ABA 100 ng. Precision (% RSD of boswellic acids) by HPLC was between 6 and 18 % and by HPTLC below 2 % for AKBA and KBA, and around 10 % for BA and ABA after derivatization. Comparison of quantification of boswellic acid in extracts by either HPLC or HPTLC showed that both methods gave identical results. HPTLC is the method of choice for routine analysis because of lower solvent consumption and fast analysis time.

Rec. Nat. Prod. 3/4, 178-186 (2009). An HPTLC method has been reported for quantitative estimation of alpha-mangostin in fruit pericarp of Garcinia mangostana (Hypericaceae). HPTLC on silica gel with chloroform - methanol 9:1 in a saturated chamber (10 min). The plate was derivatized with anisaldehyde sulfuric acid reagent. Densitometric quantification at 382 nm. Alpha-mangostin was detected as a compact band with hRf value of 46. The method was linear in the range of 1-5 µg/band. The maximum yield of alpha-mangostin was obtained from the plant by hot extraction with methanol.

J. Chem. Pharm. Res. 2(1), 155-161 (2010). A chroman derivative (C16O4H22) was isolated from the ethanolic extract of dried seeds of Ensete superbum. HPTLC on silica gel with toluene – ethyl acetate – formic acid 5:4:1. Quantitative determination by absorbance measurement at 254 nm. The linear range was 300-900 ng/band. The amount of the chroman in different fractions of the extract was 1.83 % (ethanol fraction), 1.74 % (ethyl acetate fraction) and 0.74 % (methanol fraction).

J. of Guangzhou Chem. Engin. 39(1), 144-145 (2011). A course on the technology of TLC/bioautography applied for the analysis of TCM was set-up to enhance students’ understanding of theoretical knowledge and to train and improve the interest and skill of students in chemical experiments. Demonstration of the TLC analysis of rutin and quercetin in Flos Sophorae on silica gel with ethyl acetate – formic acid – water 8:1:1. Detection under UV 254 nm and 366 nm, and by immersing into a solution of 1,1-diphenyl-2-picrylhydrazyl in ethanol (DPPH radical reagent). The result of this practice was satisfactory, and the course proved to be a good example to utilize the modern technology in the experimental teaching.

J. Planar Chromatogr. 23, 323-325 (2010). HPTLC of taraxerol on silica gel with hexane - ethyl acetate 9:1 in a saturated twin-trough chamber. Detection by spraying with anisaldehyde - sulfuric acid reagent followed by heating for 5 min at 80 °C. Quantitative determination by absorbance measurement at 540 nm. The average recovery was between 99.6 and 100.3 % with %RSD less than 2 %. For both intra-day and inter-day precision %RSD was less than 2 %. The LOD and LOQ were 47 and 140 ng/band, respectively. The linearity range was 0.5-2.5 µg/band. The hRf value of taraxerol was 22.

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.

Chinese J. of Ethnopharm. 2, 57-59 (2011). TLC of the extracts of Xinnao Tongtai capsules 1) for Lobed Kudzuvine Root, on silica gel with chloroform - methanol - water 28:10:1, detection under UV 366 nm; 2) for Szechwan Lovage Rhizome and Angelica sinensis, on silica gel with n-hexane - ethyl acetate 9:1, detection under UV 366 nm. Quantification of gastrodin by HPLC. The procedures proved to be simple, accurate, reproducible, robust and suitable for the quality control of the medicine.