J. Planar Chromatogr. 30, 251-258 (2017). HPTLC of piperine in black pepper on silica gel with toluene ‒ ethyl acetate ‒ glacial acetic acid 14:6:1. Quantitative determination by absorbance measurement at 280 nm. The hRF value for piperine was 40. Linearity was between 100 and 900 ng/zone. LOD and LOQ were 20 and 60 ng/zone, respectively. The intermediate precision was <2 % (n=6). Recovery ranged from 99.2 to 100.2 %.

CBS 119 (2017 12-13. HPTLC of hop extracts on silica gel (MS-grade) by automated multiple development using a 9-step AMD 2 gradient based on ethyl acetate – methanol – n-heptane. Quantitative determination by fluorescence measurement at 360/>400 nm with the deuterium lamp. The hRF of α-acids was 36 and of β-acids 65 and the matrix was well separated. With this study the differences in the bitter acid content of regional and varietal hops was determined. In most cases, the bitter hops contained more bitter acids than aromatic hops.

J. Chromatogr. A 1526, 157-166 (2017). Introduction of a promising alternative method for protein analysis using HPTLC with its high level of variability regarding the chromatographic system (multiple mobile and stationary phases, even mixed) and manifold detection as well as hyphenation possibilities. Silica gel, cellulose, and different RP layers were investigated with regard to their applicability for HPTLC-immunostaining. HPTLC of intact proteins on silica gel with 2-butanol – pyridine – ammonia – water 39:20:10:31; on cellulose with 2-butanol – pyridine – ammonia – water 32:30:11:25; and on RP phase with acetonitrile – trifluoroacetic acid – water 400:30:37. After development the plate was incubated with Tween20 as blocking reagent in a small vessel to inhibit unspecific binding of the antibodies to the surface. Then the plate was incubated for 2 h with the primary antibody solution and after washing with the secondary antibody for 1 h. Detection by incubating the plate in a dying solution containing 0.06% 3,3',5,5'-tetramethylbenzidine, 0.2% dioctyl sulfosuccinate sodium salt, 0.7% citric acid monohydrate, 1.8% sodium hydrogen phosphate dihydrate, 25% ethanol, and 1.5‰ dihydrogen dioxide, until blue zones appeared under white light. For the example analysis of beta-lactoglobulin on silica gel using antibovine beta-lactoglobulin antibodies, linearity was in the range of 75-2000 ng, the LOD was 62 ng/zone, the LOQ 93 ng/zone, and the accuracy 98.3%.

Food Chem. 267, 277-287 (2018). HPTLC fingerprint of proanthocyanidins, alkaloids, and anthocyanins in cocoa beans from different geographical origins on silica gel with ethyl formate – formic acid – water – toluene 60:8:6:3. Detection by dipping into a Fast Blue Salt B reagent (140 mg Fast Blue salt B in 140 mL methanol, 10 mL water, and 50 mL dichloromethane), followed by drying for 30 s. Evaluation at UV 254 nm and white light. Quantitative determination by absorbance measurement at 280 nm for alkaloids and 510 nm for anthocyanins and derivatized PA. The hRF values for epicatechin, proanthocyanidin B2, B1 and C1 and cinnamtannin A2 were 62, 37, 33, 21 and 12, respectively. The hRF values for alkaloids caffeine and theobromine were 48 and 39, respectively. The hRF values for anthocyanins cyanidin-3-O-arabinoside and cyanidin-3-O-galactoside were 12 and 19, respectively.

(Spectrophotometric determination of afugan in plant products.) Mikrochimica Acta (Wien) 1, 393-398 (1984). TLC of the fungicide afugan on silica with hexane - acetone 8:1. Detection by UV 254 nm. Spectrophotometric determination at 254 nm.

Acta Veterinaria 32, 147-152 (1984). Study on T-2 toxin, HT-2 toxin, T-2 tetraol production on cereal substrates and glycose-supplemented media. TLC on silica with benzene - acetone 12:7, visualized by spraying with 1 % 4-(p-nitrobenzyl)-pyridine, followed by heating at 150 °C for 30 min. and spraying with 3 % tetraethylene-pentamine solution.

J. Agric. Food Chem. 32, 1278-1283 (1984). Separation of methylated S containing metabolites of tributylphosphate on silica with methanol - chloroform 1:9. Detection with potassium iodide-platinochloric acid + 2,4-dinitrophenyl hydrazine.

J. Agric. Food Chem. 33, 980-987 (1985). TLC and HPTLC of fenpropathrin and metabolites on silica and cellulose using 10 different solvent mixtures, one- or two-dimensional development. Detection by autoradiography, UV or spraying with ferric nitrate, silver nitrate, triphenyltetrazolium chloride or ninhydrin.