J. Liq. Chromatogr. Relat. Technol. 31, 1903-1912 (2008). TLC of cefacetril on silica gel with methanol - acetonitrile in a sandwich chamber. The developed TLC plates were dried, then immersed briefly in the microorganism solution, and incubated for 20 h at 37 °C. After incubation the plates were sprayed with 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide solution and left at room temperature for 30 min. White inhibition zones were observed against a purple background (Chrom Biodip Antibiotic Test kit). The described procedure is suitable for screening and semiquantitative determination of antibiotic residues in milk.

J. Planar Chromatogr. 22, 43-47 (2009). HPTLC of alpha-solanine and alpha-chaconine on silica gel with dichloromethane - methanol - 2.5 % ammonia 175: 75:11 in a horizontal chamber saturated for 15 min. After drying and heating at 90 °C for 25 min detection by dipping twice in modified Carr-Price reagent (antimony(III) chloride in acetic acid - dichloromethane), followed by heating at 110 °C for 3 min. Quantitative determination by absorbance measurement at 560 nm. Linearity was between 30 and 700 ng. The limit of detection was 5-20 ng/zone depending on the sample matrix, the limit of quantification was 30 ng/zone. The ratio of alpha-chaconine and alpha-solanine was between 4:1 to 2:1 for all analyzed samples.

J. AOAC Int. 92, 699-702 (2009). HPTLC of a dinitrophenyl-lysine derivative (produced by incubation with 1-fluoro-2,4-dinitrobenzene and hydolyzation with hydrochloric acid) on silica gel (prewashed with methanol) with n-propanol - 25 % ammonia 7:3 in a twin trough chamber. Quantitative determination by absorbance measurement at 360 nm. The method was linear (r2 = 0.9991) in the range from 12.5 to 125.0 ng/band. Repeatability (%RSD) and intermediate precision (%RSD) in matrix were 0.8 % and 3.6 %, respectively. Recoveries of spiked samples at two levels ranged from 72 to 85 % with RSD from 3 to 8%. This method is a reliable, high throughput and low cost analytical method for the salmon feed industry.

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.

Food Research International 44, 1088-1093 (2011). HPTLC of resveratrol (1) and the resveratrol complex with hydrogenated soy phosphatidyl choline (2) on silica gel with dichloromethane – methanol 4:1. The hRf values of (1) and (2) were 87 and 92, respectively.

J. Planar Chromatogr. 24, 373-375 (2011). HPTLC of red clover capsule extracts and formononetin, biochanin A, daidzein, glycitein, and genistein on silica gel, prewashed with methanol, with dichloromethane - glacial acetic acid - ethyl acetate 12:2:1 in a horizontal chamber saturated for 15 min. Quantitative determination by densitometry at 260 nm. The hRf value was 29, 34, 41, 48, and 59 for daidzein, glycitein, genistein, formononetin, and biochanin A, respectively. The two major isoflavones are formononetin and biochanin A. The limit of detection and quantification was 14 and 47 ng/band for formononetin and 12 and 40 ng per band for biochanin A, respectively. The recovery was 93.3-100.7 % for formononetin and 102.0-109.4 % for biochanin A.

Chinese J. of Guangdong Agr. Sci. (9), 103-105 (2012). Garlic (Allium sativum L.) contains high levels of carbohydrates (up to 75 %), the main of which are fructo oligosaccharides (FOS). FOS have antioxidative activity. The quality control of garlic has to monitor the content of FOS because it changes during its storage. TLC of the extracts of garlic on silica gel twice with n-butanol – isopropanol – water – acetic acid 7:5:4:2, detection by spraying with vanillin – sulfuric acid – ethanol – water 3:13:81:26 and heating at 100 °C for 5 min. Up to seven monosaccharides in garlic are well separated by using the procedure.

Chinese Bulletin of Biol. 47 (7), 44-46 (2012). Chloroplast pigments play an important role in plant photosynthesis and become a kind of main raw material widely applied in the preparation of antitumor photodynamic drugs and functional foods. Phytoxanthin has outstanding function in vision protection, reducing the incidence of cataracts, anticancer therapy, and delaying the occurrence of arteriosclerosis. As a demonstration experiment for high school students analysis of chloroplast pigments by TLC and column chromatography. TLC of the extracts of fresh spinach leaves on silica gel with petroleum ether (30-60 °C) – benzene – acetone 7:1:5, detection in daylight, identification of beta-carotene (orange), chlorophyll a (dark green), chlorophyll b (light green) and phytoxanthin (bright yellow) by fingerprint comparison with the standards. Preparation by column chromatography on silica gel eluted with the same sovent system, collection of fractions, and the pure products were obtained by solvent evaporation. The results indicate that the TLC method is simple, sensitive, easy to operate, more intuitive, robust and more suitable for the purpose.