J Chromatogr A, 1619, 460945 (2020). Samples were lamotrigin as standard, or extracted with an oil-in-water microemulsion (10 µL butyl acetate, 4 mL n-butanol, 925 mg sodium dodecyl sulphate, 8.6 mL water) either from patients’ raw plasma (for separation from blood proteins) after spiking, or from commercial tablets dissolved in methanol. TLC on silica gel with a water-in-oil microemulsion of 9 mL butyl acetate, 1 mL n-butanol, 250 mg sodium dodecyl sulphate, 250 µL water. Both optimal microemulsions were predicted using Taguchi orthogonal array and Plackett-Burman design. Evaluation in UV 254 nm, quantification from the digital picture using four image processing software programs. For lamotrigin (hRF 24), limits of quantification were 170 ng for pure drug and 10 ng for spiked plasma. Linearity (in range 20–200 ng/spot) was directly obtained for the calibration curve in spiked plasma; however, for pure drug, linearity was obtained only when using log values of the calculated densities (300–3000 ng/spot).

J Chromatogr A, 1640, 461929 (2021). Study of the impact of different strains, culture media and parameters (temperature, time, rotational speed, and glucide and amino-acid supply) on the metabolite profile of bacteria. Samples were cultivation broths of Bacillus subtilis, B. licheniformis, B. pumilus and B. amyloliquefaciens, as well as their respective supernatant liquid-liquid extracts (apolar solvents only or QuEChERS method with acetonitrile and MgSO4 – NaCl mixture 4:1). HPTLC on silica gel (normal phase and RP-18), either as bands (for small volumes of extracts) or as areas for supernatants and bigger volumes of extracts. Extract areas were focused with a three-step procedure (up to 20mm with acetone, and twice with methanol); unextracted supernatants were focused twice with methanol and once with tetrahydrofuran, but the application zone of the plate had to be cut before development, due to the high matrix load. Development with ethyl acetate – methanol – water at different ratios after activation of the plate surface with magnesium chloride (33% relative humidity), evaluation in white light and UV. Detection of antibacterial compounds with Aliivibrio fischeri bioassay. Derivatization with primuline (for lipophilic substances) and diphenylamine aniline sulfuric acid reagent (for saccharides). This method allowed a fast comparison: A) of the patterns of the different strains (presence /absence and intensity of detected or antibacterial bands); B) of cultivation parameters: the number of metabolites increased with time, rotational speed (oxygen level), and at 37°C (vs. 30°C), whereas a minimal medium allowed the detection of more metabolites, due to the lower matrix load; C) of the impact of the extraction parameters: choice of the solvents (QuEChERS method had no advantage here), solvent – supernatant ratio (1:3 showed richer patterns than 1:1); D) of the HPTLC parameters used (better separation and resolution with normal phase vs. RP18 layers).

J. Liq. Chromatogr. Relat. Technol. https://doi.org/10.1080/10826076.2021.1933025 (2021). Laser fabrication of open capillary microchannels on cyclic olefin polymer susbtrates as stationary phase. Microchannels of 24 µm X 68 µm depth were produced using a neodymium-doped yttrium aluminum garnetan laser (Nd:YAG). The ultra thin layer chromatography layer was used for the separation of Fast Green for food coloring (1) and rhodamine 6G (2) and compared with a comercial RP-TLC. The hRF values for (1) and (2) were 9 and 18 using the UTLC plate and 10 and 57 with the RP-TLC plate. The paper highlighted the potential to tailor the surface chemistry through known surface functionalization routes for cyclic olefin polymer susbtrates that will allow unique applications for the UTLC plate.

(Hungarian): (Overpressured layer chromatography with gradient elution.)

J. Chromatogr. 400, 323-341 (1987). Discussion of extraction procedure, liquid-liquid distribution systems, Sep-Pak cartridges, liquid- solid chromatography using silica, alumina and chemically modified silica packings, macroreticular resins and gel permeation columns for the analysis of PAHs in environmental samples by TLC. TLC of 6 PAHs in air particulate and diesel particulate extracts on RP-18 silica with acetonnitrile - methanol - water 1:5:1. Identification by coincidence of retention between sample and standards. Quantification by densitometry.

J. Chromatogr. 436, 467-473 (1988). Presentation of a method for the determination of title compounds based on mild alkaline deacylation and acid hydrolysis of plasmalogens on plate with subsequent micro-TLC on silica. Quantification by phosphorus absorption method.

J. of Chromatogr. A 1218 (37), 6540-6547 (2011). New approach and application of highly automated planar chromatographic tools for powerful clean-up, called high-throughput planar solid phase extraction (HTpSPE), which is indispensable for preventing matrix effects in multi-residue analysis of pesticides in food by liquid and gas chromatography coupled to mass spectrometry, employing TLC to completely separate pesticides from matrix compounds and to focus them into a sharp zone, followed by extraction of the target zone by the TLC-MS interface, thus resulting in extracts nearly free of interference and free of matrix effects, as shown for seven chemically representative pesticides in four different matrices (apples, cucumbers, red grapes, tomatoes), and completion of clean-up of one sample in a manner of minutes. Regarding the clean-up step, quantification by LC–MS with mean recovery (against solvent standards) of 90–104% and relative standard deviations of 0.3–4.1% (n = 5) for two spiking levels of 0.1 and 0.5 mg/kg.

Chromatographia 27, 617-621 (1989). Evaluation of the florisil clean-up procedure for its suitability of quantifying aflatoxin in sorghum grain by bi-directional HPTLC. Investigation of the accuracy and precision of the method. Detec tion limits, 0.13˜0.36 µg/kg. Comparison with the AOAC CB method.