J. Planar Chromatogr. 21, 15-20 (2008). TLC and OPLC of polyacetylenes of chamomile, trans-resveratrol, salicylic acid, and ochratoxin A on silica gel (preconditioned at 120 °C for 3 h) with chloroform - methanol 20:1. Detection by bioautography with Pseudomonas savastanoi pv. phaseolicola race 6 and by immersing the humid plate into MTT solution for 5 s.

Phytochem. Anal. 19, 116-121 (2008). HPTLC of cinnamaldehyde (1) in the shoots of Cinnamomum zeylanicum, eugenol (2) in the flower buds of Eugenia caryophyllus and piperine (3) in the fruits of Piper nigrum on silica gel with petroleum ether - dichloromethane - formic acid 20:40:1. Quantitative determination by absorbance measurement at 290 nm. The hRf values were 47, 61, and 12 for (1), (2), and (3), respectively. Linearity was between 54 and 735 ng/spot for (1), 533 and 8531 ng/spot for (2), and 50 and 300 ng/spot for (3). The limits of detection and quantification were 12 and 21 ng/spot for (1), 240 and 426 ng/spot for (2), and 18 and 40 ng/spot for (3). Recovery was 99 % for each substance. No significant intra- and interday variation was observed. The method proved to be rapid and useful in comparison with GC and HPLC methods.

Phytochem. Anal. 20, 19-23 (2009). TLC of curcumin (1), demethoxycurcumin (2), and bisdemethoxycurcumin (3) from the rhizomes of Curcuma longa on silica gel with hexane – chloroform – methanol 10:10:1 as mobile phase. Quantitative determination by recording the chromatogram using a digital scanner and analyzing the density of the TLC spot with the Scion Image software. The hRf values of (1), (2), and (3) were 42, 25, and 18, respectively. Selectivity regarding matrix was given. Linearity was between 0.375 and 6 µg/spot for all curcuminoids. The intermediate precision of the method was satisfactory. Recovery was 101.9 % for (1), 104.8 % for (2), and 101.5 % for (3). The limits of detection and quantification were 43 and 143 ng/spot for (1), 69 and 230 ng/spot for (2), and 73 and 242 ng/spot for (3). The method was compared with an official densitometric method, and the analytical results were not significantly different.

Indian Drugs 44(12), 937-944 (2007). HPTLC of the methanolic extract of Sesamum indicum root (Pedaliaceae) and its ethyl acetate fraction on silica gel with ethyl acetate - n-hexane 1:9. Absorbance measurement at 549 nm. The red zone was isolated by preparative TLC and identified by IR to be a 1,4-naphthoquinone derivative.

J. Planar Chromatogr. 22, 55-58 (2009). TLC of plaunotol in leaves of Croton stellatopilosus Ohba, on silica gel with chloroform - n-propanol 24:1 in a twin trough chamber saturated for 30 min. Quantitative determination by absorbance measurement at 220 nm. Recovery was 98.7 %. The plaunotol content of the leaves of C. stellatopilosus was highly variable (0.14 to 0.79 % w/w of dry weight).

Rev. Fac. Agron. 21, 155-160 (2004). HPTLC of betaxantin and betacyanin in the roots of Beta vulgaris on cellulose in two one-dimensional developments with 1) isopropanol – ethanol – water – acetic acid 6:7:6:1 and 2) isopropanol – ethanol – water – acetic acid 11:4:4:1. Qualitative identification under UV light. Betaxantin and betacyanin showed maximum absorbances at 537 and 465 nm, respectively. The hRf values of betaxantin and betacyanin were 22 and 34, respectively.

J. Chromatogr. A 1216 (11), 2150-2155 (2009). Chaihu roots (Bupleuri radix), roots of Bupleurum chinense and Bupleurum scorzonerifolium are monographed in the Chinese Pharmacopoeia. Evaluation of the quality of 33 lots of authenticated Chaihu samples versus 31 lots of commercial samples by HPLC-ELSD and HPTLC analysis of the principal bioactive components (saikosaponins). Data acquired from HPLC fingerprints and HPTLC fluorescent images was analyzed by chemometrics for similarity and pattern recognition, including artificial neural networks, k-nearest neighbor (k-NN) and an expert’s panel. The k-NN classifier showed good performance with sufficient flexibility for processing HPTLC fingerprint images. These images were otherwise not easily dealt with by other algorithms due to the shift of hRf values and varying hue/saturation of the band colors between different TLC plates. The two chromatographic fingerprint methods are complementary measures for quality control. Chaihu roots from different species of the genus Bupleurum could readily be distinguished from each other. Commercial samples of Chaihu can easily be classified by investigating the content of major saikosaponins.

J. Planar Chromatogr. 22, 371-376 (2009). HPTLC of indolizidine alkaloids and extracts on silica gel and RP-18 (both prewashed with chloroform-methanol 1:1) with 11 mobile phases in a horizontal chamber without chamber saturation. The best resolution was achieved on silica gel with chloroform - methanol 20:1. Detection under UV 254 nm and after spraying with Dragendorff reagent. Quantitative determination of securinine and allosecurinine by absorbance measurement at 254 nm. The limit of detection and quantification was 11 and 36 ng/zone for securinine and 12 and 41 ng/zone for allosecurinine, respectively.