Food Control. 68, 220-228 (2016). HPTLC of biogenic amines (putrescine, histamine, tyramine and agmatine) in microbial cultures on silica gel with chloroform – benzene – triethylamine 12:9:2. Quantitative determination by absorbance measurement at 254 nm.

J. Liq. Chromatogr. Relat. Technol. 40, 239-246 (2017). Review of TLC methods for the analysis of polyphenols, dyes, carboxylic acids, biogenic amines, and vitamin C in quality assessment and authentication of non-fermented or fermented beverages derived from fruits.

J. Chromatogr. A 1477, 108-113 (2016). In order to study the kinetics of invertase, a specific fructofuranosidase was cloned from the Leishmania major genome. Determination of the kinetic parameters of the β-D-fructofuranosidase by TLC on silica gel impregnated with sodium bisulfate and citrate, developed successively twice with acetonitrile – water 4:1. Detection of the three carbohydrates sucrose, glucose and fructose by dipping the plates in a solution of 4-aminobenzoic acid. Quantitative determination by UV-densitometry. Description of the hydrolysis of sucrose by the Michaelis-Menten kinetic parameters (KM, Vmax) equal to 63.1 ± 7.6 mM, 0.04 ± 0.001 mM/min using glucose production and 83.0 ± 14.4 mM, 0.03 ± 0.002 mM/min monitoring fructose. Also, comparison of hydrolyses of three alternative substrates, raffinose, stachyose and inulin, and characterization of the regiospecificity of the reaction. The method proved to be suitable for the refined kinetic analysis of different reactions related to the hydrolysis of sugars.

J. Planar Chromatogr. 30, 291-298 (2017). HPTLC of cefuroxime axetil and cefepime in human whole blood and urine on silica gel with chloroform – ethyl acetate – glacial acetic acid – water 4:4:1:3 for (1) and ethanol – 2-propanol – glacial acetic acid – water 4:4:1:3 for (2). Quantitative determination at UV 285 nm for (1) and 266 nm for (2). The hRF values for (1) and (2) were 89 and 21, respectively. Linearity was between 3-77 μg/mL for (1) and 3-38 μg/mL for (2). The intermediate precision (n=6) was <2 % for (1) and (2). LOD and LOQ were in the range of 40 and 470 ng/zone. Recovery rate ranged from 95.8 to 101.5 % for (1) and (2).

Trends. Anal. Chem. 98, 79-94 (2018). Review of essential protocols for the quantification of dairy-related contaminants, including the application of HPTLC for the determination of residual pesticides such as chlorpyrifos, bifenthrin, deltamethrin, cyhalothrin and imidacloprid and antibiotics such as cephalosporin.

CBS 118, 5-7 (2017). Presentation of two HPTLC methods for 1) detection and identification of UV filter substances in suncream and 2) detection of phenolic markers in Edelweiss species (Leontopodium spp.). For 1) HPTLC of sun cream samples and standards octocrylene, avobenzone, octisalate and ensulizole on silica gel first with heptane – ethyl acetate 4:1 with chamber saturation, migration distance 70 mm, then with isopropanol, without saturation, migration distance 28 mm. Densitometric evaluation by absorbance measurement at UV 254 nm. Direct elution of target zones into a single quadrupole MS, detection in positive and negative ionization mode. For 2) HPTLC of methanolic and glycerol-based Edelweiss extracts and standards chlorogenic acid, apigenin, luteolin, luteolin-4-O-glucoside, luteoline-7-O-glucoside, leontopodic acids A and B, cynarine, and 3,5-dicaffeoylquinic acid on silica gel with butyl acetate – formic acid – water 280:100:3 with chamber saturation, migration distance 70 mm. Detection by heating the plate at 100 °C for 3 min and immersing (while still hot) into natural products reagent (1 g of 2-aminoethyl diphenylborinate in 200 mL ethyl acetate). Evaluation under UV 366 nm.

CBS 119 (2017 12-13. HPTLC of hop extracts on silica gel (MS-grade) by automated multiple development using a 9-step AMD 2 gradient based on ethyl acetate – methanol – n-heptane. Quantitative determination by fluorescence measurement at 360/>400 nm with the deuterium lamp. The hRF of α-acids was 36 and of β-acids 65 and the matrix was well separated. With this study the differences in the bitter acid content of regional and varietal hops was determined. In most cases, the bitter hops contained more bitter acids than aromatic hops.

J. Chromatogr. A 1490, 201-211 (2017). HPTLC for comparison of the phenolic profiles of polar extracts from Populus nigra L. (1), Populus alba L. (2) and Salix alba L. (3) buds. Five chemotypical patterns were distinguished after derivatization with Natural Products reagent and confirmed by principal component analysis. The HPTLC analysis was directly hyphenated to various microbiological and biochemical assays as well as spectrometric techniques, which directly linked to active molecules in the chromatograms. The results showed that polyvalent compounds were evident when all derivatization and activity assays were combined together. Detection of at least three antimicrobial compound zones using Aliivibrio fischeri and Bacillus subtilis bioassays and of one phyto-estrogen with the planar yeast estrogen screen in Populus buds. Detection of several inhibitors of acetyl- and butyrylcholinesterase and rabbit liver esterase in all samples. Bioactive compounds were assigned by HPTLC-MS, e.g. chrysin as selective cholinesterase inhibitor, and caffeic acid and galangin as antimicrobials in (1) and (2). The method is suitable to determine the botanical origin and quality of Populus bud extracts and propolis samples.