J. Planar Chromatogr. 33, 419-425 (2020). Immunochromatography of cannabinoids (1) and opiates (2) in human urine using a test cassette device consisting of five parts, including a plastic backing, sample pad, conjugate pad, absorbent pad, and nitrocellulose (NC) membrane. Visual LOD was 50 ng/mL for (1) and 300 mg/mL for (2). Recovery was between 98 and 111 % for (1) and 101 and 110 % for (2).

J. Planar Chromatogr. 33, 365-370 (2020). HPTLC of lupeol (1) and β-sitosterol (2) in the stem bark of Crataeva nurvala on silica gel with toluene - methanol 24:1. Detection by spraying with 1 % anisaldehyde - sulfuric acid reagent, followed by heating at 110 ºC. Quantitative determination by absorbance measurement at 545 nm. The hRF values for (1) and (2) were 48 and 34, respectively. Linearity was between 2 and 6 µg/zone for both (1) and (2). Intermediate precision was below 2 % (n=3). The LOD and LOQ were 43 and 133 ng/zone for (1) and 57 and 173 ng/zone for (2), respectively. Average recovery was 98.6 % for (1) and 98.1 % for (2).

J. Planar Chromatogr. 33, 263-269 (2020). HPTLC of the interaction between methylene blue and purified glutathione-S-transferase (5 mmol/L methylene blue and enzyme solution in 0.1 mol/L potassium phosphate buffer) on silica gel with butanol - acetic acid - water 12:3:5 for 2 h. Detection by spraying with ninhydrin (0.25 % in acetone). The complex that most likely came from the interaction of methylene blue and purified glutathione-S-transferase had a hRf of 16.

J. Planar Chromatogr. 33, 245-253 (2020). HPTLC of twenty-one chalcones on RP-18 with three binary combinations (acetonitrile - water, ethanol - water and acetone - water) in the following compositions: 1:1, 3:2, 7:3 and 4:1. Detection at UV 254 nm. Acetonitrile - water was found to be the most suitable system for lipophilicity prediction of tested compounds using calculated logP values. Quantitative structure-retention relationship (QSRR) analysis was performed to identify the most important structural and physico-chemical properties that influence retention behavior of tested compounds.

J. Planar Chromatogr. 33, 271-279 (2020). Two-dimensional HPTLC of cholic, ursodeoxycholic, chenodeoxycholic, deoxycholic, and lithocholic bile acids on silica gel with 0.0001 M cetylpyridinium chloride at pH 9 with the addition of aliphatic alcohol modifiers 4 % 1-butanol (direction II) and 0.6 % 1-pentanol (direction II). Detection by drying the plate for 2-3 min in the oven at 120 ºC, followed by spraying with 8 % sulfuric acid in ethanol. Qualitative determination under UV light at 365 nm.

Phcog. Mag. 15, 440-448 (2019). HPTLC fingerprint of Psidium guajava on silica gel with toluene - ethyl acetate - formic acid 6:3:1. Qualitative determination under UV light at 254 and 450 nm. The hR_F values of common metabolites were 3, 18 and 42 in both aqueous and n‑butanol fractions.

Pharmacogn. Mag. 16, 227-234 (2020). HPTLC fingerprint of Evolvulus alsinoides on silica gel with toluene - ethyl acetate - formic acid 14:6:1. Qualitative determination under UV light at 254 nm. Detection of antioxidant molecules using 2,2‑Diphenyl‑1‑picrylhydrazyl (DPPH) assay.

J. Sep. Sci. 43, 1431-1439 (2020). HPTLC fingerprint of flavan-3-ols and proanthocyanidins in five different Rosa species (R. canina, R. glutinosa, R. rubiginosa, R. multiflora, and R. spinosissima) on silica gel with n-propanol - water - acetic acid 4:2:1. Detection by dipping into 4-dimethylaminocinnamaldehyde solution (60 mg  in 13 mL of concentrated hydrochloric acid, which was made up to 200 mL with ethanol). Qualitative determination under UV light at 366 nm. The blue zones visible on the derivatized plate were used for further analysis using a TLC-MS interface. The flavanol and proanthocyanidin profiles of Rosa species depend on the geographical origin rather than on the cultivar and genotype.