J. Planar Chromatogr. 10, 463-464 (1997). TLC on silica with hexane (12 cm), and, after drying - in the same direction - with petrol ether (10 cm). Detection by spraying with 20% ethanolic phosphomolybdic acid and heating at 105°C. Quantification by densitometry at 600 nm.

J. Planar Chromatogr. 23, 250-254 (2010). TLC of 30 food additives (aldehydes, organic acids, esters and alcohols, and various sodium salts) on titanium(IV)silicate ion-exchanger with 10 different mobile phases: e. g. methanol, heptane - diethylether 4:1, aqueous ammonia - methanol - ethyl acetate 1:3:6, methanol - aqueous ammonia 9:1, methanol - ethanol 17:3, 0.5 M ammonium sulfate solution, 0.25 M, 0.5 M and 0.1 M potassium bromide solution, and phosphate buffer pH 2.5 in a twin-trough chamber without chamber saturation. Detection by spraying with 1 % iron chloride solution, 0.5 % potassium permanganate and 3 % barium chloride solution 1:1, 1 % ninhydrin in ethanol, 2 % phosphomolybdic acid in ethanol, and 5 % potassium dichromate in concentrated sulfuric acid. The study shows that the quality of separation depends to a large extent on the mobile phase, and selectivity is achieved by varying the composition of the mobile phase.

Thin-layer chromatographic procedure for the identification of preservatives in cosmetic products. J. Chromatogr. 410, 395-411 (1987). TLC of 88 preservatives on silica and alumina with ethyl acetate - diisopropyl ether - 96% ethanol - 25% NH3 55:30:10:2. Detection under UV 254 nm and by spraying with six reagents. Investigation of the retention behavior and the detectability of the preservatives, of which 74 were characterized. Detection limit, in the concentration range of 0.1%.

Z. Lebensm. Unters. Forsch. 206, 99-102 (1998). TLC of phenolic compounds on silica gel with a mixture of chloroform - methanol - water 63:35:10. Visualization by spraying with a solution of ferric chloride and potassium ferricyanide. Compounds with antioxidative activity were visualized after spraying with a solution of b-carotene and linoleic acid and observing the delay in bleaching of the b-carotene.

J. Planar Chromatogr. 28, 436-442 (2015). TLC of hydrocortisone acetate (1), fusidic acid (2), methyl paraben (3) and propyl paraben (4) on silica gel with methylene chloride – methanol – benzene 10:2:5. Quantitative determination by absorbance measurement at 240 nm. The hRF values for (1) to (4) were 13, 32, 49 and 59. The polynomial calibration range was between 1-15 μg/zone for (1) to (4). The intermediate precision was below 1.8 % (n=3). Recovery ranged 99.6-100.2 %.

J. Agric. Food Chem. 39, 351-355 (1991). TLC of antioxidants (a,ß,d-tocopherols, ferulic acid, catechol) on silica with toluene - methyl formate - formic acids 5:4:1, toluene - chloroform - acetone 8:5:7 and benzene - pyridine - formic acid 36:9:5. Detection with Folin-Ciocaltau’s phenol reagent; anisaldehyde - sulfuric acid ; 0.5% fast blue.

(Identification and quantification of propyl, octyl, and dodecyl gallates in olive oils and butters by thin layer chromatography.) Trav. Chim. Aliment. Hyg. 89, 355-368 (1998). TLC of gallates on acetylcellulose with toluene - isopropanol - acetic acid - formic acid 15:2:1:2 or on silica gel with petroleum ether - benzene - acetic acid 2: 2:1. TLC of butylhydroxyanisole and butylhydroxytoluene on silica gel with petroleum ether - ethyl acetate 10:1. Visualization with 1% ethanolic iron(III)chloride solution. Densitometry at 580 nm.

J. Planar Chromatogr. 29, 306-309 (2016). HPTLC of some red, rose, and white wines on silica gel with ethyl acetate – acetic acid – formic acid – water 10:1:1:2. Antioxidant activity determination by dipping into a 0.04 M methanolic 2,2-diphenyl-1-picrylhydrazyl (DPPH radical reagent) solution (1) and into a 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) solution (2; prepared by mixing 7 mM ABTS diammonium salt solution with 2.45 mM potassium persulfate solution 1:1). The plates were then dried in the fume hood and stored in the dark. The antioxidant activities were determined after 10 and 30 min reaction time. Method (2) was more sensitive than the DPPH assay.