CBS 109, 2-4 (2012). Extraction of arabica coffee with 2 to 50 % robusta coffee by accelerated solvent extraction with tBME. A part was saponified with10 % ethanolic KOH solution for 2 h. HPTLC of coffee extracts and standards 16-O-methylcafestol (16-OMC) and 16-OMC esters on silica gel with toluene - ethyl acetate - acetic acid 93:7:1 for 16-OMC esters and with tBME - chloroform 1:1 for 16-OMC. Detection by spraying with vanillin sulfuric acid (1 g in 250 mL ethanol and 2 mL of sulfuric acid, prepared freshly) and heating for 1 min at 80 °C. Quantitative absorption measurement at 530 nm. The LOD was 163 ng/band. After saponification the LOD of free 16-OMC was 43 ng/band. Thus 2 % robusta can be detected in a coffee blend.

J. Planar Chromatogr. 28, 139-143 (2015). TLC of 16 polyaromatic hydrocarbons on RP-18 phase. In the first direction, the plate is developed twice with n-pentane at -20 °C, and in the second direction with acetonitrile - methanol - water 12:8:3:3. Both developments were carried out over a distance of 43 mm. Detection by chemiluminescence: a solution of 225 mg Bis(2,4,6-trichlorophenyl)oxalate dissolved in 45 mL of n-butyl acetate was prepared. 125 μL hydrogen peroxide 30 % were vigorously shaken with this solution for 20 min. The mixture is suitable for chemiluminescence measurements within a period of 48 h. The best results were observed when the plate was dipped in this solution for 1 s and dried until no light reflection could be seen on the surface. Then, the TLC plate was covered by a glass plate and measured for 1 min using a very light-sensitive CCD camera. The proposed chemiluminescence screening method is able to separate PAHs from PAH oxidation products and detects benzo[a]pyrene and perylene with a LOD of 95 pg/band for benzo[a]pyrene and 48 pg/band for perylene. Although these compounds were separated from all other PAHs in the standard, a separation of both compounds was not possible from one another.

CBS 116, 11-12 (2016). HPTLC of lactose in milk, yoghurt, and instant sauce on silica gel with acetonitrile – water 3:1 (with 0.1 % trifluoroacetic acid) to the migration distance of 5 cm. Detection by spraying with aniline-diphenylamine-phosphoric acid reagent (2 g diphenylamine and 2 mL aniline in 80 mL methanol, 10 mL of o-phosphoric aicd 85 %, filled up to 100 mL) and heating for 10 min at 120 °C. Evaluation under white light. Elution of zones from the underivatized plate into ESI-MS with acetonitrile – water 19:1 (with 0.1 % formic acid) and detection in positive ionization mode. The method is suitable for semiquantitative determination of lactose by image evaluation and allows for confirmation of lactose-free products as such.

Planta Medica 82 (16), 1395-1402 (2016). The hexane – ethyl acetate subfraction of the ethyl acetate fraction of an ethanolic Tabebuia roseoalba leaf percolation extract was subfractioned on a silica gel column with 42500 mL of a gradient of hexane, ethyl acetate, and methanol. For monitoring, TLC on silica gel with hexane – ethyl acetate 1:1, detection with anisaldehyde sulfuric acid reagent. Two fractions that gave only one visible zone on TLC, were identified by NMR as mixtures of stigmasterol and sitosterol, and of alpha- and beta-amyrins, respectively.

Food. Res. Int. 102, 282-290 (2017). HPTLC of fructooligosaccharides in pure orange juice on silica gel with n-butanol – 2-propanol – water 10:5:4. Detection by spraying with a mixture of phosphoric acid (6.8 mL), urea (3 g) and ethanol (8 mL) in 100 mL of 1-butanol – water 8:1, followed by heating at 120 °C for 10 min. Quantitative determination by absorbance measurement at 450 nm.

Planta Medica 83(14/15), 1149-1158 (2017). The cyclodextrane fractionation of the methanolic percolate of Salix reticulata aerial parts was analyzed on silica gel with ethyl acetate – methanol – water 100:13:10. Detection by derivatization with vanillin-sulfuric acid reagent. Luteolin and apigenin glycosides, catechin, procyanidins and phenolic glucosides (picein, triandrin, and salicortin) were isolated from these fractions through preparative HPLC._x000D_

J. Planar Chromatogr. 3, 228-231 (1990). HPTLC separation of neutral lipids and phospholipids on silica with hexane - ether 6:4 (for neutral lipids) and chloroform - methanol - triethylamine - water 30:35:35:8 for phospholipids. detection by immersion for 1 min in a modified molybdate reagent. Quantification by densitometry at 595 nm.

J. Chromatogr. 564, 272-277 (1991). TLC on silica with petrol ether - ether (peroxide free) – acetic acid 90:30:1. Detection by spraying with chloroform – methanol 1:1 containing 232 x 10-6 M 2,5-bis-2-(5-tert.-butylbenzoxazolyl)thiophene, and inspecting under UV 365 nm. Quantification by GC.