J Chromatogr A, 1603, 355–360 (2019). Samples were ethyl acetate root macerates of fully flowered Tanacetum vulgare (Asteraceae). HPTLC on silica gel (classical irregular particles vs. Lichrosphere with spherical particles) previously washed with methanol, dried for 5 min at room temperature, perimeter-sealed with a polymer coat, and heated for 30 min at 100 °C. Separation with toluene or with toluene – n-hexane 7:3, in classical capillary flow or in OPLC (overpressured layer chromatography). For OPLC, off-line infusion was used (closed mobile phase (MP) outlet, automatically stopping development); external pressure 50 bar, rapid MP flush 175 and 350 µL, MP flow rate 250 and 500 µL/min, 1830 and 3475 µL MP, development time 446 s and 424 s. Derivatization by immersion into vanillin – sulfuric acid reagent, followed by 5 min heating at 110 °C; or into PABA reagent (500 mg p-aminobenzoic acid, 18 mL glacial acetic acid diluted, 20 mL water, 1 mL o-phosphoric acid, 60 mL acetone), followed by 5 min heating at 140 °C. Effect-directed analysis using automated immersion: A) for free radical (DPPH•) scavengers; B) for activity against Gram-negative bacteria using Aliivibrio fischeri bioluminescence assay; C) for activity against Gram-positive bacteria with Bacillus subtilis bioassay. Four active polyynes were identified as hexadiynylidene-epoxy-dioxaspiro-decane (1), pontica epoxyde (nonene-triynyl-vinyl-oxirane) (2), tetradeca-triine-en-one (3) and trans-(hexadiynylidene)-dioxaspiro-decene (4), by hyphenating OPLC to quadrupole-orbitrap HRMS without eluent, using a DART interface (Direct Analysis in Real-Time, needle voltage 4kV, grid voltage 50 V, helium as gas, temperature 500 °C, full scan in positive ionization mode in m/z range 100-750). Polyynes (3) and (4) were coeluting in HPTLC but not in OPLC, demonstrating that (4) is not produced by oxidation during the DART-MS procedure. Separation with OPLC compared to HPTLC was performed in a shorter time and with better resolution at the same time. Layers with spherical particles gave higher resolution; zone distortions occurring in OPLC due to dissolved air in MP were prevented by previous MP sonication.

J. Liq. Chromatogr. Relat. Technol. 43, 319-327 (2020). Review of impregnated agents used in TLC and their applications in analytical and medicinal chemistry. Impregnation with inorganic ions, chelating reagents, lipophilic substances, surfactants, chiral selectors and ionic liquids were discussed.

J. of Chromatogr. A 1591, 162-170 (2019). TLC of malachite green (1) and fast green (2) on diatom biosilica (a nanostructured, porous stationary phase composed of randomly-deposited biosilica frustules isolated from living cells of diatom Pinnularia sp.) instead of conventional silica gel with 1-butanol - ethanol - water 9:1:1 and 1-butanol - acetic acid - water 5:1:2. Diatom biosilica reduced the flow velocity and permeability constant by a factor two compared to silica gel and thus improved the resolution of (1) and (2). The theoretical plate height for both analytes was reduced ten-fold with 1-butanol - acetic acid - water 5:1:2, and the difference in retention time between malachite green and fast green was increased (ΔhRF 26) with 1-butanol - ethanol - water 9:1:1.

J. Planar Chromatogr. 24, 290-294 (2011). Preparation of a new plate from silica gel and glass powders sintered on an aluminium nitride ceramic plate by bonding octadecyl and methyl silanes in suitable proportion. Besides its high mechanical stability and regeneration ability, the plate was well suited for planar chromatography and was superior in eliminating joule heating. Superior results are expected when pressurized PEC can be used.

Trends Anal. Chem. 87, 1-18 (2017). This review described the application of nanocellulose in analytical chemistry, including the use of electrospun cellulose acetate nanofibers as separation media in TLC for steroids in medical products. These nanofibers were resistant to protic solvents and some non-polar solvents. Interestingly, thinner plates were obtained using such nanofibers, lowering the limit of detection when compared with commercial silica plates.

Chromatographia 20, 109-111 (1985). Study of TLC behaviour of 28 phenolic compounds on semicrystalline stannic tungstate layers with various solvent systems. Detection by spraying with suitable chromogenic reagents. Dimethyl sulfoxide was found to act as self detector for a number of phenols. A number of binary, ternary and quarternary separations of bioanalytical and immuno-physiological importance have been achieved

J. Liquid Chrom. 9, 3447-3459 (1986). Description of two basic theories for adsorption TLC optimization: thermodynamic adsorption theory and theory based on mass action law (so called Snyder's theory). Application on chromatographic systems using chitin as stationary phase for separation of amino acids. Results were comparable for systems with silica gel as stationary phase

J. Chromatogr. 407, 314-318 (1987). HPTLC on silica treated with phenyldimethylethoxy-, diphenylmethylethoxy- and triphenylethoxysilanes, with acetonitrile - water 75:25 and 80:20. Quantification by densitometry at 265 nm and 275 nm, resp. Discussion of the relationship between the retention indices and solvent composition.