J. Agric. Food Chem. 50, 1200-1206 (2002). TLC of 1-methylpyridinium on silica gel with ethyl acetate - methylethylketone - formic acid - water 5:3:2:1. Detection under UV.

Eurasian J. Anal.Chem. 5(1), 21-24 (2010). A stability-indicating HPTLC method has been developed for simultaneous estimation of amlodipine besylate and nebivolol hydrochloride. HPTLC on silica gel with ethyl acetate - methanol - 25% ammonia 17:2:2. The hRf value of amlodipine besylate was 40 and of nebivolol hydrochloride 60. Densitometric quantification at 240 nm for amlodipine and 260 nm for nebivolol. The method was linear in the range of 500-2000 ng/band for both compounds. Degradation products formed under stress conditions (acid, alkali, oxidative, dry heat, photo degradation) were well separated from the main compound. The method was suitable for quality control and stability studies.

62nd Indian Pharmaceutical Congress Abstract No. F-261 (2010). TLC of montelukast sodium and levocetirizine dihydrochloride on silica gel with ethyl acetate – methanol – ammonia 10:2:1. Quantitative determination by absorbance measurement at 231 nm. Montelukast and levocetirizine were subjected to acid, base, peroxide, and photodegradation. In stability tests the drugs were susceptible to acid and basic hydrolysis, oxidation and photolytic degradation. The stressed samples were analyzed by the proposed method and no intereference of the degradation products or the excipients with the drugs was found. The linearity ranges were 50-600 ng/zone for levocetirizine and 100-1200 ng/zone for montelukast. The recovery was 99.3 % for levocetirizine and 99.9 % for montelukast.

J. Liq. Chromatogr. Relat. Technol. 37, 2814-2828 (2014). HPTLC of arylureas and arylacetamides derivatives on RP-18 with 1-13 % water in dimethylsulfoxide (increment 3 %). Detection under UV 254 nm. A quantitative structure-retention relationship study allowed to investigate the retention behavior of these substances as well as determination of lipophilicity related to the biological activity towards dopamine D2 and 5-hydroxy-tryptamine receptors.

V. Danube Symposium on Chromatography Yalta, November 11 -16, 1985. TLC of piperazine, N-hydroxy-ethyl piperazine, N, N'-bis (hydroxyethyl) piperazine, N-p-chlorobenzhydryloxy ethoxy ethyl piperazine on silica with methanol - NH3 100:1.5. Detection with Dragendorff reagent.

Anal. Biochem. 175, 258-262 (1988). TLC of tetrodotoxin and related substances, anhydro tetrodotoxin and tetrodonic acid on silica with pyridine - ethyl acetate - acetic acid - water 15:5:3:4. Identification by fast atom bombardement MS. Detection limit, 0.1 µg.

J. Planar Chromatogr. 5, 465-467 (1992). TLC of 8 azaarenes on cellulose with DMF - water mixtures 65:35, 50:50, 35:65, 20:80, 10:90. After drying visualization under UV 254 nm and exposure to trifluoroacetic acid vapor followed by visualization under UV.

The effect of pH. J. Planar Chromatogr. 11, 64-69 (1998). Determination of the lipophilicity and specific hydrophobic surface area of 21 fused-ring nitrogen heterocycles by RPTLC and study of the effect of different mobile-phase additives such as acetic acid, sodium acetate, and lithium chloride on the retention. Regular retention behavior was observed for each solute, the RM value decreasing linearly with increasing concentration of acetonitrile in the mobile phase. RPTLC of 21 nitrogen containing heterocycles on silica gel impregnated with paraffin oil. Detection after drying at 105°C under UV and by exposure to iodine vapor.