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.

VII. Comparison of analytical methods for determination of impurities in tetracycline pharmaceutical preparations. J. Chromatogr. 314, 303-311 (1984). HPTLC of various tetracyclines on silica with acetone - 5 % aq. sol. of Na2 EDTA 10:1 and RP-TLC on C18-plates with methanol - acetonitrile - 0.5 M oxalic acid (aq. pH 2.0) 1:1:4 or 1:1:2. Detection by UV 366 nm or with 0.5 % Fast Violet B aq. solution and pyridine. Quantification by scanning at the dual-wavelength mode at 366/600 nm for 4-epitetracycline and chlortetracycline and at 425/650 nm for anhydrotetracycline and 4-epianhydrotetracycline. RP-TLC-densitometry appears to be a precise method for the determination of tetracyclines.

R.E. Kaiser (Ed) "Proc. of the 3rd Int. Symp. on Instr.HPTLC, Wuerzburg", Bad Duerkheim 1985, 71-82. Description of the principle of automated multiple development technique and a fully automatic machine for the complexe developing process. A universal elution gradient is suitable for the separation of compounds differing widely in their polarity and those with unknown chromatographic behaviour. Several application examples.

J. Chromatogr. 339, 163-169 (1985). TLC of nitrazepam and its main metabolites on silica with acetone - ethyl acetate - 28 % NH3 1:9:0.1. Quantification by direct UV densitometry. Detection limit 5-10 ng/ml.

Pharm. Anal. (Yaowu Fenxi Zazhi) 5, 117-118 (1985). (Chinese) (Determination of yam sapogenins by TLC-densitometry.). TLC of sapogenins in yam tubers on silica with chloroform - acetone 97:3. Quantification by densitometry.