J. Ethnopharmacol. 197, 157-164 (2017). HPTLC of picroside I (1) and picroside II (2) in Picrorhiza kurroa on silica gel with ethyl acetate – methanol – acetic acid 46:1:1. Quantitative determination by absorbance measurement at 270 nm. The hRF values for (1) and (2) were 52 and 68, respectively.

J. Chromatogr. Sci. 54 (7), 1096-1104 (2016). TLC of the extracts of the dried aerial parts of 12 plants of Cirsium species and five selected standards (naringin, apigenin, rutin, caffeic acid and chlorogenic acid) on silica gel with ethyl acetate – formic acid – acetic acid – water 24:3:3:8 on RP-18 phase with 5 % aqueous solution of formic acid – methanol 7:3 for the first development and the same system in the ratio of 1:1 for the second development. Analysis of the results by chemometrics. The comparison of individual Cirsium species and the identification of unknown species by using the similarity indices (Pearson's correlation coefficient, determination coefficient and congruence coefficient), distance indices (Euclidean distance, Manhattan distance and Chebyshev's distance) and Multi-Scale Structural SIMilarity. Based on chemometric analysis, the first extract of the widely grown species is identified as Cirsium arvense and the second one as Cirsium rivulare.

J. Planar Chromatogr. 30, 440-452 (2017). For electroseparation experiments in a commercially available, open-air electrophoresis box, thirteen types of separation layers (filtrating paper, office paper, chromatography paper, Japanese paper for aircraft paper models, potato starch on cellulose support, common HPTLC glass plates coated with cellulose, silica gel, RP-18W, and aluminum oxide as well as glass-based nutrient agar layers) were investigated. The best separation was observed for the cellulose pre-coated TLC layer and the starch layer on filtrating paper support. The study revealed substantial differences between the electrophoretic migration of target dyes within cellulose type layers and also in comparison to the remaining stationary phases studied. Combined planar electrophoresis–electrochromatography of methyl red and ponceau R colorants on active thin-layers composed of starch powder on cellulose strips and agar layer on glass-based support connected with electrolyte containers. The resulting dye pattern on active layers was acquired using an office scanner.

CBS 117, 11-12 (2006). For the rapid control of the fish species escolar (Lepidocybium flavobrunneum) by determination of the indigestible wax esters, HPTLC on silica gel with n-hexane – toluene 7:3 with chamber saturation for 10 min, migration distance 60 mm. Detection by dipping in aqueous Rhodamine B reagent (0.025 %), evaluation under UV 366 nm. Quantitative determination by fluorescence measurement at 366/>400 nm with the Hg lamp. The hRF value of oleyl oleate was 30 and of stearyl stearate 40. The mean recovery rate (104 %) was determined by analyzing salmon samples spiked to contain 20 % wax esters. The wax ester content of an escolar sample was 18-22 % (n=3). The repeatability was <5 % and the mean laboratory precision 3 %.

J. Chromatogr. Sci. 56 (1), 81-91 (2018). HPTLC of mixures of tamsulosin hydrochloride (TAM) with either tolterodine tartrate (TOL) or solifenacin succinate (SOL) in bulk drug and in combined dosage forms on on silica gel with ethyl acetate – methanol – ammonia 120:80:1. Quantification by densitometry at 224 nm. Linearity was between 0.1-0.7, 0.4-4 and 1-6 μg/band for TAM, TOL and SOL, respectively.

Rev. Bras. Farmacogn. 28/1, 92-101 (2018). HPTLC fingerprint of Eugenia uniflora on silica gel with ethyl acetate – formic acid – water 18:1:1. Detection by spraying with natural products reagent followed by PEG reagent. Qualitative identification under UV 365 nm. The hRf values of gallic acid, myricetrin and ellagic acid were 71, 34 and 38, respectively.

J. Chromatogr. A 1507, 124-131 (2017). Fast HPTLC-fluorescence detection (HPTLC-FLD) screening of the total ergot alkaloids in rye using lysergic acid amide (LSA) as chemical marker. Generally these substances are determined by HPLC-FLD or mass selective detection, analyzing the individual compounds. For analysis by HPTLC-FLD, transformation of the ergopeptine alkaloids selectively to LSA after an ammonium acetate buffered extraction step followed by liquid-liquid partition for clean-up. HPTLC on silica gel with isopropyl acetate – methanol – water – 25 % ammonium hydroxide solution 800:100:38:11. Quantitative determination using the enhanced native fluorescence of LSA and ergometrine at 313/>400 nm without any interfering matrix. The LOD and LOQ were 8 and 26 μg/kg LSA in rye, which enables the determination of the total ergot alkaloids far below the limit for rye. Recoveries were close to 100 % for different rye flours at relevant spiking levels. The screening method proved to be reliable, fast and efficient for the total ergot alkaloids in rye, and is a rapid alternative to the HPLC analysis of the individual compounds.

J. Planar Chromatogr. 31, 497-504 (2018). HPTLC of chloroacetamide derivatives on RP-18 with ethanol and tetrahydrofuran as organic modifiers with water. Lipophilicity was examined by cluster analysis and principal component analysis. The obtained chromatographic parameters of the examined acetamides were correlated with the standard measure of lipophilicity, log P.