Food Chem. 416, 135822 (2023). A chip consisting of two parts: a pesticide residue reaction and a separation area cut from a TLC plate was used for the analysis of pesticides dichlorvos, paraoxon and parathion in spiked cabbage, cucumber and spinach with 40 % dd water - acetonitrile solution. Once the pesticide was absorbed by the pesticide enrichment zone, the TLC plate was removed and allowed to dry in the air for 1 min, followed by adding the esterase enzyme solution (prepared from crushed malted barley) and incubation at 37 °C for 3 min. Detection by overlapping with a substrate cromogenic area impregnated with dichloroindophenol acetate. A scanner and digital image-processing was performed to quantify adsorbed substances. LOD was 2 ng/g for dichlorvos, 6 ng/g for paraoxon, and 3 ng/g for parathion.

J Chromatogr A, 1624, 461239 (2020). Samples were chemical standards of acetylcholinesterase (AChE) inhibitors (azamethiphos, caffeine, donepezil, galanthamine, methiocarb-sulfoxide, paraoxon-ethyl) and of neurotoxic compounds, as well as drinking or contaminated water samples enriched through solid phase extraction. HPTLC on spherical silica gel (pre-washed twice by 20 min immersion in isopropanol, heated 20 min at 120 °C before and after pre-washing with acetonitrile). First separation (preparative TLC) with automated multiple development (16 steps). Effect-directed analysis for AChE inhibitors by immersion (speed 5 cm/s, time 1 s) into enzyme solution, incubation 5 min at 37 °C and immersion into substrate solution (indoxyl acetate 2 % in methanol); visualization under UV 366 nm. Active zones from untreated layers were eluted through the oval head of a TLC-MS interface to a second plate for a second separation with a panel of other mobile phases. Bands of interest were eluted from the second layer with water through the oval elution head of the TLC-MS interface pump, into a RP18 liquid chromatography guard column, followed by a quadrupole time-of-flight mass spectrometer. Full scan mass spectra (m/z 100–1200) were recorded in negative and positive modes using electrospray ionization (and collision-induced dissociation for MS2). Among the water contaminants, lumichrome (riboflavin photolysis product), paraxanthine and linear alkylbenzene sulfonates were identified as AChE inhibitors.

J. Planar Chromatogr. 33, 533-546 (2020). Review of chromogenic spray reagents for the detection and identification of organic pesticides by TLC and HPTLC. Specific applications for the analysis of organochlorine pesticides, organophosphate pesticides, carbamates and synthetic pyrethroids were described.

J. Planar Chromatogr. 33, 255-262 (2020). HPTLC of triazophos in human whole blood on silica gel with n-hexane - acetone 4:1. Quantitative determination by absorbance measurement at 248 nm. The hRF value for triazophos was 18. Linearity was between 2 and 100 µg/mL. Intermediate precision was below 2 % (n=5). The LOQ was 2 µg/mL. Average recovery was 90.7 %.

J. Planar Chromatogr. 33, 203-206 (2020). HPTLC of profenofos in visceral samples on silica gel with hexane - acetone 7:3. Detection by spraying with cupric acetate reagent (4 g of cupric acetate in 100 mL distilled water), followed by heating at 120 ºC for 10 min. The hR_F value for profenofos was 44.

J. Chromatogr. A 1594, 181-189 (2019). Development of a simple and rapid procedure for the determination of quinalphos in human whole blood by HPTLC on silica gel with n-hexane – acetone 9:1 after extraction from spiked blood samples with the optimum solvent, diethyl ether, at pH 3 (average recovery = 93.6%), detection and quantification by densitometry at 325 nm in absorbance mode. Validation by examination of the effect of different organic solvents and pH on the extraction yield of quinalphos, and by investigation of the interference of other organophosphorus pesticides of forensic relevance (not observed). The linearity was in the range of 1 to 100 μg/mL with r2 = 0.9981, the sensitivity (LLOQ) at 1 μg/mL. The within-day precision and between-day precision ranged from 0.2 to 1.0%, and 0.1 to 0.8%, respectively, with an overall average recovery of 91.1% at three concentrations 1, 10, and 50 μg/mL. For different storage conditions for the samples no significant decrease in the concentration of quinalphos was observed. Application of developed procedure in three fatal cases of poisoning.

J. Planar Chromatogr. 32, 435-437 (2019). HPTLC of glyphosate in biological material (viscera, liver, spleen, kidney and lungs) on silica gel with methanol - ammonia 9:1. Detection by spraying with chromogenic reagent (2.0 g cobalt(II) chloride and 3.0 g ammonium thiocyanate in 100 mL distilled water). The hRF value for glyphosate was 46. LOD was approximately 3 µg. Recovery rate was 100.2 % for (1), 100.1 % for (2) and 99.9 % for (3).

J. Planar Chromatogr. 32, 61-64 (2019). HPTLC of monocrotophos in biological samples (pieces of stomach, small and large intestine, liver, spleen, kidney, and lungs) on silica gel with hexane - acetone 19:1. Detection by spraying with a chromogenic reagent (2 g chloranil mixed with 2 g sodium nitrite dissolved in 10 % nitric acid solution). The hRF value of monocrotophos was 76.