J. Planar Chromatogr. 34, 203-209 (2021). HPTLC of triclosan in toothpaste on silica gel with n-heptane - methyl tert-butyl ether - acetic acid 920:80:1. Detection by spraying with 2,6-dichloroquinone-4-chloroimide in 50 mL methanol, followed by spraying with an aqueous sodium carbonate solution (1 g/10 mL). Plates were scanned using a flatbed scanner. The hRF value for triclosan was 22. Linearity was between 100 and 1000 ng/zone. The LOD and LOQ were 46 and 91 ng/zone, respectively. Average recovery was 93.2 %.

J. Planar Chromatogr. 34, 253-261 (2021). HPTLC of emtricitabine (1) and tenofovir alafenamide fumarate (2) on silica gel with ethyl acetate - n-hexane - methanol - ammonia solution 20:20:10:1. Quantitative determination by absorbance measurement at 260 nm. Linearity was between 400 and 2000 ng/zone for (1) and 50 and 250 ng/zone for (2). Intermediate precisions were below 2 % (n=3). The LOD and LOQ were 29 and 87 ng/zone, respectively. Recovery was between 100 and 102 % for (1) and 100 and 103 % for (2).

J. Planar Chromatogr. 34, 271-278 (2021). HPTLC of tedizolid phosphate on silica gel with chloroform - methanol 9:1. Quantitative determination by absorbance measurement at 300 nm. The hRF value for tedizolid phosphate was 46. Linearity was between 10 and 2000 ng/zone. Intermediate precisions were below 2 % (n=6). The LOD and LOQ were 3 and 10 ng/zone. Recovery was between 98.5 and 101.7 %.

J. Planar Chromatogr. 34, 189-195 (2021). HPTLC of tacrolimus on silica gel with acetonitrile - ethyl acetate - glacial acetic acid 60:20:20:1. Detection by spraying with anisaldehyde reagent (0.5 mL of p-anisaldehyde was mixed with 10 mL of glacial acetic acid, 85 mL of methanol and 5 mL of sulfuric acid), followed by heating at 100 °C for 3 min. Quantitative determination by absorbance measurement at 366 nm. The hRF value for tacrolimus was 20. Linearity was between 20 and 140 ng/zone. Intermediate precisions were below 3 % (n=3). The LOD and LOQ were 6 and 17 ng/zone, respectively. Mean recovery was 101.6 %.

Sens. Actuators. B. Chem. 325, 128753 (2020). Leucomalachite green (1) and malachite green (2) and certain amount of highly dispersed potassium iodate titanium dioxide composites (0.1 M titanium butoxide was used as a precursor with 5 % potassium iodate solution to prepare KIO3-doped TiO2 nanoparticles). The sample was developed with chloroform - methanol 4:5. Detection by dipping into 5 % potassium iodine, followed by heating and then dipping into a zinc ion solution followed by heating at 80 °C. Linearity was in the range of 0.3–8.0 μg/mL for (1) and 0.1–4.0 μg/mL for (2), respectively. LOD and LOQ were 1.7 and 5.2 μg/kg for (1) and 0.9 and 2.7 μg/kg for (2), respectively.

Food Chem. 351, 129211 (2021). High-throughput planar solid-phase extraction of 66 multi-class antibiotic residues in muscle tissue, cow milk and chicken eggs on silica gel with acetonitrile - methanol - ammonia 5:3:2 as first front-elution up to 85 mm followed by a second front-elution in the reverse direction up to 25 mm with acetonitrile -water - ammonia 9:7:4. Evaluation under UV 254 nm and 366 nm. Detection of macrolides by spraying with p-anisaldehyde sulfuric acid reagent (methanol - glacial acetic acid - sulfuric acid - p–anisaldehyde 420:50:26:3), followed by heating at 110°C for 3 min. Detection of penicillins by spraying with ninhydrin reagent (500 mg ninhydrin in ethanol - glacial acetic acid 23:2). Detection of lincosamines by spraying with aniline diphenylamine o-phosphoric acid reagent (2 g diphenylamine in methanol – o-phosphoric acid - aniline 90:10:1). Via simple clicks on the image, the auto TLC-MS interface automatically eluted the target zones at the trace level from the TLC plate into a Q Exactive Plus Hybrid Quadrupole-Orbitrap Mass Spectrometer.

J. Liq. Chromatogr. Relat. Technol. https://doi.org/10.1080/10826076.2021.1968429 (2021). Review of bioautography procedures of antimicrobial compounds in plants, including extraction of plant material, stationary and mobile phases in direct bioautography, chemical derivatization and biological detection of bioactive compounds and structure elucidation of bioactive bands. The paper also discussed new aspects of identification of biologically active substances in accordance with the principles of green analytical chemistry, and with special reference to substances with antimicrobial properties.

J. Liq. Chromatogr. Relat. Technol. https://doi.org/10.1080/10826076.2021.1930555 (2021). HPTLC of ofloxacin (1), tinidazole (2), terbinafine hydrochloride (3), and clobetasol propionate (4) on silica gel with toluene - ethyl acetate - methanol - triethylamine - formic acid 50:40:10:3:3. Quantitative determination by absorbance measurement at 238 nm. Linearity was between 300 and 1500 ng/zone for (1) to (4). The intermediate precision was below 2 % (n=6). Recovery was between 98.9 and 99.1 % for (1), 98.9 and 99.3 % for (2), 99.0 and 99.5 % for (3) and 98.9 and 99.3 % for (4).