J. Planar Chromatogr. 4, 259-261 (1991). TLC of citral on silica with hexane – chloroform 7:3. Quantification by densitometry (absorbance) at 250 nm.

Jap. Hygienic Chem. (Eisei Kagaku) 37, 542-551 (1991). Description of a systematic method for detection of 15 artificial dyes and 19 natural dyes in foods. Extraction with water followed by dichloromethane. Fractionation of water-soluble dyes by polyamide chromatography, and of oil-soluble ones by liquid-liquid, silica, and alumina column chromatography. Identification of the dyes in each fraction by TLC. The method is simple and can be applied to various kinds of food.

J. AOAC Int. 76, 335-341 (1993). TLC of sulfamethazine and sulfabromomethazine on silica with ethyl acetate 1:1; detection after mechanical dipping at low speed for 2 s in 100 mL fluorescamine solution (25 mg in 10 mL acetone, to which 90 mL hexane is added). The dipped plate is dried 5 min. with nitrogen, then sprayed with 0.2 M H3BO3 (pH adjusted to 8.0 with 1 M NaOH), placed in - 20°C freezer for 5 min. before densitometry in fluorescence mode. Estimation of detection limit 0.25 ppb.

J. Agric. Food. Chem. 43, 64-69 (1994). TLC of wine phenolics on silica with chloroform - methanol 9:1; detection of phenol groups with Folin - Ciocalteu reagent, of antioxidant active compounds with a solution of linoleate - ß-carotene (1 mM/50 µM in chloroform).

J. Agric. Food. Chem. 42, 381-387 (1994). Analytical and preparative TLC of moxidectin and metabolites on silica with dichloromethane - ethyl acetate - formic acid 34:6:8, on RP-18 with acetonitrile - water 18:2; incremental multiple development TLC procedure was used to separate and isolate metabolites on RP-18 silica with acetonitrile - water 9:1 and on silica with ethyl acetate - hexane 5:2. Radioactive zones located by autoradiography.

J. Planar Chromatogr. 8, 78-80 (1995). HPTLC of nitroimidazoles (dimetridazole, metronidazole, ronidazole) in poultry on silica with ethyl acetate. Detection with fluorescamine (detection limit 15 - 20 ng) and by spraying with pyridine, waiting for 1 min and illumination under UV 366 nm (detection limit 3 - 25 ng).

Fat Sci. Technol. 97, 20-23 (1995). Preparative TLC for the determination of lipid classes on silica with petrol ether - acetone 10:1. Detection by spraying with a 0.01% ethanolic solution of a fluorescent indicator. Analysis of the triglyceride groups according to their unsaturation degree by argentation TLC and densitometry. TLC on silica impregnated by dipping into a 0.5% methanolic silver nitrate solution with petrol ether - acetone 200:7 resp. 200:11. Detection by heating at 105 °C for 1 h, then allowing to stand for 30 min under bromine vapor, then for additional 30 min under sulfuryl chloride vapor, and finally heating for 4-5 min at 180-200 °C. Quantification by densitometry at 450 nm.

J. AOAC Int. 79, 375-379 (1996). TLC of oxytetracycline or chlorotetracycline in animal feeds in the presence of 11 other drugs (3 nitrofurans, 2 macrolide antibiotics, 3 sulfonamides, 2 coccidiostatics, 1 antibacterial growth promoter) on silica with chloroform - methanol 10:1. Detection under UV 254 and 366 nm. Quantification after microbiologically elution by the agar diffusion method. Limit of quantification 0.625 ppm, recovery 92.9 %, CV 2.3 - 4.4 %.