J. AOAC Int. 91, 1387-1396 (2008). HPTLC on silica gel with chloroform - methanol 9:1 in the first direction for curcumin, demethoxycurcumin, bis(demethoxy)curcumin, and the synthetic dye metanil yellow, and with toluene - hexane - acetic acid 50:50:1 for sudan I and sudan IV in the second direction. Quantitative determination by absorbance measurement at 420 nm for curcumin and metanil yellow, at 491 nm for sudan I, and at 520 nm for sudan IV.

J. Planar Chromatogr. 28, 6-11 (2015). TLC of nine reactive dyes, seventeen fluorescent brighteners (nine of them are triazine-stilbene derivatives and eight of them are 2-aminodimethylterephthalate derivatives) and their intermediates (twenty four in number), all of them containing 4-amino-2,2,6,6-tetramethylpiperidine stabilizer fragment, on silica gel with n-propanol - ammonia - ethyl acetate 3:2:4 or heptane - propanol 1:1. Detection at UV 254 nm.

J. Planar Chromatogr. 30, 113-120 (2017). HPTLC of brilliant green, green fat, green S, iochrome black, oil red, natural red, rhodamine, patent blue, brilliant blue, brilliant black, azorubin, ponceau 4R, allura red, tartrazine, 1-aminoanthraquinone, (4-[2-pirydylazo]resorcinol), quinoline yellow, thymol blue and curcumin on RP-18 by isocratic elution with different concentrations of methanol in water (0-100 % v/v) with addition of 100 mM trifluoroacetic acid (TFA); and by gradient elution using a 2012 proposed horizontal developing chamber for stepwise gradient elution in reversed-phase mode, with different concentrations of methanol and buffer (pH=3.0, 3 mM citric acid and 1.5 mM disodium hydrogen phosphate in deionized water). When the citrate buffer was replaced by TFA the front of the mobile phase was more uniform and the phenomenon of flow of the mobile phase to the surface of the adsorbent layer was not observed; therefore, the substance zone was well shaped. The best gradient separation was obtained with a 4-step convex gradient: the concentrations of methanol in subsequent fractions of the mobile phase were 40, 60, 70, and 80 % (v/v) and the migration distances of the fractions were 10, 10, 20 and 30 mm, respectively. The total development distance was 70 mm. The results showed high repeatability within the same plate and between studies. The highest values of precision (%RSD >2 %) were obtained for the most strongly retained substances (oil red, dye No. 8, and fat green, dye No. 2).

The effect of support and the organic phase in the eluent. Chromatographia 25, 908-914 (1988). Determination of the lipophilicity of some photosynthetic pigments by reversed-phase TLC on silica, alumina, cellulose, polyamide and diatomaceous earth with water - acetone and water - ethanol. Investigation of the effect of support and the organic phase in the eluent.

J. Chromatogr. 538, 157-164 (1991). TLC of the commercial and CCC-purified substances on silica with acetone – chloroform – butyl amine 132:48:9. Spectrophotometry after band scraping.

Proc. 9th Internat. Symp. Instr. Chromatogr., Interlaken, April 9.-11., 305-310 (1997). OPLC of quinoline yellow, sunset yellow, cochineal red A, indigo carmine, tartrazine, amaranth, erythrozine, on silica with mixed ternary phases as eluent. Detection by densitometry. For quantification the following mobile phases were chosen as the best: NH3 - methanol - ethyl acetate 1:3:6 and NH3 - ethyl methyl ketone - butanol 2:3:5. Densitometry.

J. Planar Chromatogr. 17, 444-448 (2004). TLC of 16 naphthalimide dyes, 17 benzanthrone dyes, 20 triazine dyes, and 17 fluorescent brighteners on (mainly) silica gel with n-heptane - acetone 1:1 and 3:1, chloroform - methanol 1:1 and 2:1, n-heptane - benzene - chloroform 3:2:1, n-heptane - chloroform - acetone 2:2:1, n-butanol - pyridine - 25 % ammonia 1:1:1, chloroform - methanol - 25 % ammonia 11:5:1, n-propanol - 25 % ammonia 1:1 and 2:1, n-butanol - acetic acid - water 4:1:5. Quantitative determination by UV-scanning densitometry.

Anal. Chem. 81, 3056-3062 (2009). TLC of organic dyes and pigments (alizarin, purpurin, carminic acid, lac dye, crocin, Cape jasmin) on silica gel with toluene - acetic acid - methanol 9:2:2. After sample application a centrifuged citrate-reduced silver colloid was spotted on top of the applied zones. SER spectra were recorded soon after application of the colloids.