CBS 107, 5-7 (2011). HPTLC of coenzyme Q10 in toluene extracts of soft gel capsules on silica gel (pre-washed by development from both sides with methanol) with toluene in the horizontal developing chamber from both sides. Detection under UV 254 nm. The hRf value of coenzyme Q10 is 20. Quantitative absorption measurement at 282 nm, evaluation via peak height. Linearity was in the range of 20-50 ng/band. Polynomial calibration ranged 20-150 ng/band. The parallel analysis of 60 samples (10 samples each from 6 batches) and 12 standards required only 86 min. The test for content uniformity was performed with 10 samples according to the European Pharmacopoeia and the USP 34 and the requirements were met.

J. Chromatogr. A 1532, 198-207 (2018). Development of a method to analyze the efficiency of a diverse set of natural deep eutectic solvents (NADES) for the extraction of compounds of interest from two model plants, Ginkgo biloba and Panax ginseng. HPTLC on silica gel with toluene – ethyl acetate – acetone – methanol 50:25:25:3 for ginkgolides in Ginkgo biloba leaves; with ethyl acetate – acetic acid – formic acid – water 100:11:11:27 for phenolics in Ginkgo biloba leaves; with toluene – ethyl acetate – acetic acid 40:10:1 for ginkgolic acids in Ginkgo biloba leaves; with chloroform – ethyl acetate – methanol – water 15:40:22:10 for ginsenosides in Panax ginseng leaves and stems. The six different NADES were combinations of two or three compounds mixed in defined molar ratios, e.g. malic acid – choline chloride 1:1, malic acid – glucose 1:1, choline chloride – glucose 5:2, malic acid – proline 1:1, glucose – fructose – sucrose 1:1:1 and glycerol – proline – sucrose 9:4:1. Processing the data obtained by multivariate data analysis showed differences between the extracts. Discussion of the foreground of application of NADES in green chemistry and the advantages of NADES as green solvents used in novel green products for the food, cosmetics and pharmaceuticals.

J. Liq. Chrom. Rel. Technol. 27, 1981-1992 (2004). Study of the interaction between cholesterol and non-ionic surfactants by reversed-phase TLC using cholesterol-impregnated TLC plates and methanol - water mixtures. TLC on aluminum oxide impregnated by overnight pre-development in a solution of cholesterol dissolved in chloroform - acetone 1:1. 20 surfactants were tested (Arcopal, Sapogenat, Tween, Genapol, Myrj, and Brij). The intercept obtained from linear regression anal. (RM0), being characteristic for the strength of interaction, and the slope (b), being related to the surface area of surfactants in contact with cholesterol, were detected. Stepwise regression anal. (SRA) was performed to find relation between the structural parameters of surfactants and strength of interaction. Stacking interaction exists between cholesterol and the aromatic ring of the surfactants. The number of ethylene oxide units and length of the carbon chain in the surfactant molecules have significant effect on the strength of the interaction between the compounds studied.

CBS 100, 2-5 (2008). HPTLC of photodegraded UV filters and sunscreen on silica gel LiChrospher prewashed with methanol. AMD 2 development of UV filter standards photodegradation products with diisopropylether - n-hexane in 6 steps over 50 mm without preconditioning, and of sunscreen samples photodegradation products with t-butylmethylether - n-hexane in 7 steps over 50 mm with preconditioning, followed by drying at 120 °C for 30 min. Detection at 254 and 366 nm, followed by biodetection via dipping the plate in a Vibrio fischeri solution for 1 s and evaluation with the Bioluminizer (exposure time 55 s). Densitometric evaluation by multi-wavelength scan at 200-400 nm.

J. Planar Chromatogr. 25, 168-173 (2012). HPTLC of arbutin in commercial whitening creams with methanol - chloroform - acetic acid 7:12:1. Quantitative determination by absorbance measurement at 254 nm. The hRf value of arbutin was 40. LOD and LOQ were found to be 42 and 112 ng/zone, respectively.

Identifizierung mittels Dünnnschicht-Chromatography. (Analysis of microbiocidal isothiazolones. II. Identification by thin-layer chromatography.) Fresenius Z. Anal. Chem. 319, 520-523 (1984). TLC of isothiazolone formulations, used for preservation of cosmetics and technical products, on silica with 6 different solvent systems. Detection with 10 spray or detection methods (e.g. Dragendorff reagent, iodine vapours, UV 254 nm).

J. Planar Chromatogr. 17, 369-371 (2004). TLC of 9-phenylxanthene derivatives (fluorescein, erythrosine, eosin, rhodamine B, and their allyloxy-derivatives) on silica gel with benzene - methanol 5:1, toluene - ethanol 7:1, acetontrile - water 7:1, toluene - ethyl acetate - methanol 1:5:2. Detection under UV light at 254 nm or with iodine vapor. Quantitation by densitometric scanning.

J. Liq. Chromatogr. Relat. Technol. 31, 1857-1870 (2008). HPTLC of phospholipids (phosphatidic acid, phosphatidylcholin, phosphatidylethanolamine, phosphatidylinositiol, lysophosphatidic acid, lysophosphatidylcholine, lysophosphatidylethanolamine, and lysophosphatidylinositol) on silica gel with chloroform - methanol - water - 25 % ammonia 60:34:4:2 in a twin-trough chamber saturated for 20 min. Plates were conditioned to 47 % relative humidity. Detection by dipping for 6 s in modified copper sulfate reagent (20 g copper (II) sulfate pentahydrate were dissolved in 200 mL of cooled methanol, then under cooling 8 mL of sulfuric acid 98 % and 8 mL of ortho-phosphoric acid 85 % were added) followed by drying in cold air for 30 s and heating at 140 °C for 30 min. Quantitative determination by absorbance measurement at 360 nm, 420 or 720 nm, or by video densitometry. Investigation of several parameters of the chromatographic process, including chamber saturation, derivatization, plate activity, and batch to batch consistency of the plates. For reproducible results, the employed methodology must be strictly standardized.