J. Planar Chromatogr. 27, 204-209 (2014). HPTLC of naringin in the leaves and stems of Rumex vesicarius on silica gel with ethyl acetate - glacial acetic acid - methanol - water 30:10:5:1. Quantitative determination by absorbance measurement at 275 nm. The hRF value for naringin was 46. Linearity was in the range of 100-1000 ng/zone. The intermediate/interday/intra-day precisions were below 2 % (n=6). The LOD and LOQ were 37 and 111 ng/zone, respectively. The average recovery was 99.5 %.

J. Liq. Chromatogr. Relat. Technol. 37, 2420-2432 (2014). HPTLC of lamivudine (1) and zidovudine (2) on silica gel with ethyl acetate – hexane – methanol – acetic acid 40:40:20:1. Quantitative determination by absorbance measurement at 278 nm. The hRF values for (1) and (2) were 25 and 73, respectively. Linearity was in the range of 100-600 ng/zone for (1) and 200-1200 ng/zone for (2). The intermediate/interday/intra-day precisions were below 2 % (n=3). The LODs and LOQs were 5 and 15 ng/zone for (1) and 10 and 32 ng/zone for (2), respectively. Recovery was between 95 and 105 %.

J. Planar Chromatogr. 27, 186-191 (2014). HPTLC of rutin (1), rosmarinic acid (2), and glycyrrhizin (3) in the medicinal preparation Savda Munziq on silica gel with ethyl acetate - formic acid - acetic acid - water 30:2:2:3. Quantitative determination by absorbance measurement at 250 nm. The hRF values for (1) to (3) were 16, 86 and 9, respectively. Linearity was in the range of 128-2048 ng/zone for (1), 322-5144 ng/zone for (2) and 70-1120 ng/zone for (3), respectively. The intermediate/inter-day/intra-day precisions were below 3 % (n=3). The LOD and LOQ were 37 and 124 ng/zone for (1), 38 and 127 ng/zone for (2) and 33 and 111 ng/zone for (3), respectively. Recovery for (1) to (3) was in the range of 95.4-104.0 %.

J. AOAC Int. 98, 1226-1233 (2015). HPTLC of three phosphodiesterase type 5 inhibitors, sildenafil (1), vardenafil (2), and tadalafil (3), and eight of their analogs, hydroxyacetildenafil (4), homosildenafil (5), thiohomosildenafil (6), acetildenafil (7), acetaminotadalafil (8), propoxyphenyl (9), hydroxyhomosildenafil (10), hydroxyhomosildenafil (11) and hydroxythiohomosildenafil (12) in finished products on silica gel with TBME - methanol - ammonia 28% 20:2:1. Detection under 254 and 366 nm UV light and by absorbance measurement at 232 nm. LOD was 30 ng/zone for all substances. Confirmation by HPTLC-ESI-MS. The method was successfully_x000D_ applied to screening of 45 commercial lifestyle products. Of those, 31 products tested positive for at least one illegal component (sildenafil, tadalafil, propoxyphenyl, hydroxyhomosildenafil, or dimethylsildenafil).

J. Chromatogr. A 1473, 133-142 (2016). Development of a simple, accurate and precise method for the analysis of proton pump inhibitors and their co-formulated drugs, available as binary combination, by HPTLC on silica gel with toluene – iso-propranol – acetone – ammonia 50:23:25:2. Identification of 14 analytes (except for rabeprazole and lansoprazole which could not be separated) based on hRf and recorded peak spectra. Qantitative determination by densitometry at 290 nm. The linear response for the selected drugs was good with correlation coefficients ≥0.9993. The LOD and LOQ was between 7-160 ng/band and 21-478 ng/band, respectively, for all the analytes. Assessment of the method performance by analyzing different laboratory simulated mixtures and some marketed formulations of the selected drugs, and successful application of the method to investigate potential counterfeit of proton pump inhibitors through a series of simulated formulations with good accuracy and precision.

CBS 118, 13-15 (2017). HPTLC of nicotine in liquids for electronic cigarettes (e-liquids) on silica gel Nano-ADAMANT with dichloromethane – methanol – 28 % ammonia 224:25:1 to the migration distance of 70 mm. Quantitative determination by absorbance measurement at 260 nm. The hRF of nicotine was 38. Confirmation by overlay of UV spectra of standard and sample.

J. Planar Chromatogr. 31, 243-249 (2018). HPTLC of diazinon (1) and chlorpyrifos (2) in the leave extracts of lavender and rosemary on silica gel with petroleum ether – ethanol – glacial acetic acid 95:5:1 for (1) and 90:10:1 for (2). Quantitative determination by absorbance measurement at 254 nm. The hRf values for (1) and (2) were 54 and 50, respectively. Linearity was in the range of 10-1600 ng/zone for (1) and 40-2000 ng/zone for (2). The intermediate precision was below 2 % (n=3). The LOD and LOQ were 3 and 10 ng/zone for (1) and 12 and 40 ng/zone for (2), respectively. Average recovery was 100.8 % for (1) and 99.9 % for (2).

Proc. Intern. Symposium on TLC with special Emphasis on OPLC, Szeged, 9-10 (1984). OPLC (OPTLC) of citral, citronellol, eugenol, cinnamon, menthol, mentha on silica with chlorobenzene. Detection with vanillin-sulfuric acid reagent. Densitometry by absorbance at 600 nm.