J. Planar Chromatogr. 29, 366-371 (2016). HPTLC of the diastereomeric amides of (RS)-etodolac on silica gel with acetonitrile – methanol – dichloromethane – water 12:2:2:1. Detection by exposure to iodine vapor. The hRf value for the first and second eluting diastereomers were 22 and 56, respectively.

J. Planar Chromatogr. 30, 106-112 (2017). RP-HPTLC (1) and micellar liquid chromatography-TLC (2) of 1,2,4-triazole derivatives on RP-18 with methanol and acetonitrile in volume range concentration between 0.3 and 0.65 organic modifier for (1) and sodium dodecyl sulfate concentrations above critical micellar concentration in the range between 0.0318 and 0.1318 mol/L for (2). Detection by exposure to iodine vapors at room temperature. Developments were performed in moderate (≈0.4 T) magnetic field and simultaneously outside it. The partition coefficient P value of the investigated substances was used as a descriptor of their lipophilic properties.

and Cassia angustifolia Vahl. J. Planar Chromatogr. 30, 238-244 (2017). HPTLC fingerprint of sennoside A and B in Cassia senna L. and Cassia angustifolia on silica gel with 1-propanol ‒ ethyl acetate ‒ water 4:4:3. Detection by heating at 110 °C for 10 min, followed by spraying with 50 g/L potassium hydroxide in ethanol 50 % and heating again at 110 °C for 10 min. Qualitative determination at UV 366 nm.

J. Ethnopharmacol. 197, 184-194 (2017). HPTLC of arjunetin in Terminalia arjuna on silica gel with ethyl acetate – toluene – formic acid – acetic acid 12:6:1:2. Detection by spraying with anisaldehyde sulfuric acid reagent. The hRF value for arjunetin was 25.

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).

J. AOAC Int. 100, 414-421 (2017). HPTLC of two binary mixtures containing pyridoxine hydrochloride (1) with either cyclizine hydrochloride (2) or meclizine hydrochloride (3) on silica gel with dichloromethane – acetone – methanol 14:2:1. Quantitative determination by absorbance measurement at 220 nm. The hRF values for (1-3) were 7, 25 and 80, respectively. Linearity was in the range of 0.2-5 μg/zone for (1) and 0.2-4 μg/zone for (2) and (3). The LOD and LOQ were 60 and 190 ng/zone for (1), 50 and 170 ng/zone for (2) and 60 and 170 ng/zone for (3), respectively. The intermediate precision was <2 % (n=3). Average recovery rate was 99.9 % for (1) and (3) and 100.1 % for (2).

J. Chromatogr. Sci. 55 (5), 564-570 (2017). Determination of the chromatographic retention data for 13 new 5-arylidene-2,4-thiazolidinediones on cyano phase and RP-18 with 6 aqueous binary mobile phases modified with acetonitrile, methanol, ethanol, propanol, acetone and dioxane. Presentation of 3 attempts to find suitable quantitative structure–retention relationship (QSRR) models that quantify retention as a function of molecular descriptors. It was found that models built for RP-18 show generally better multiple R but are also mostly monoparametric with logP as the dominant descriptor. More informative from the standpoint of molecular interactions are QSRR models for cyano phase, and the quality of those models depends on the mobile phase modifier (the best was acetone and the worst propanol). It is suggested to consider extrapolated retention on cyano phase as alternative to standard RP-18 for further assessment of plasma protein binding, since all QSRR models use extrapolated retention as a property which is indirectly connected with plasma protein binding.

CBS 119 (2017) 14-15. HPTLC of Cannabis sativa and standards cannabidiol (CBD), tetrahydrocannabinol (THC), and cannabinol (CBN) on silica gel with n-heptane – diethyl ether – formic acid 75:25:0.3 with chamber saturation for 20 min to a migration distance of 70 mm. Detection by spraying with Fast Blue salt B reagent (250 mg o-dianisidine bis(diazotized) zinc double salt in 10 mL water, 25 mL methanol and 15 mL dichloromethane), evaluation under white light. Quantitative determination by absorbance measurement at 210 nm prior to derivatization (for cannabinoid acids 285 nm). For the screening of THC-free samples the limit test can be used. The EU limit of 0.2 % is easily detected with or without detection. The %RSD of the assay prior to derivatization is 1.5 % and after derivatization 2.1 %. The LOD is 10 ng/zone.