J. Liq. Chromatogr. Relat. Technol. 40, 725-731 (2017). HPTLC of butylated hydroxytoluene (BHT) in Antarctic krill on silica gel with petroleum ether – ethyl acetate – hexane 8:2:1. Detection by spraying with 5 % aqueous ferric chloride followed by heating at 105 °C for 5-10 min. Quantitative determination by absorbance measurement at 600 nm. The hRF value for BHT was 79. Average recovery was 101.8 %.

and Glycyrrhiza uralensis Fisch.) by HPTLC, validated by HPLC and DNA sequencing. J. Planar Chromatogr. 30, 467-473 (2017). HPTLC of 18-β-glycyrrhizic acid in two licorice root species (Glycyrrhiza glabra L. and Glycyrrhiza uralensis Fisch) on silica gel with dichloromethane – methanol – water – formic acid 120:75:15:1 with chamber saturation for 20 min to a migration distance of 70 mm. Quantitative determination by absorbance measurement at 254 nm. Detection of species by immersion into sulfuric acid reagent, followed by heating at 100 °C for 10 min, evaluation under UV 366 nm and white light. The HPTLC results correlate with the data obtained by HPLC and by DNA sequencing.

J. Chromatogr. A 1530, 211-218 (2017). Development of a novel and cost-effective TLC method on cellulose (instead of silica gel) for authentication of selected fruit-based alimentary products. As authenticity markers the anthocyanins cyanin chloride, keracyanin chloride, pelargonidin chloride and delphinidin chloride were used. With TLC, the LOD and LOQ for cyanin were of 25 and 75 ng/zone, for keracyanin 55 and 166 ng/zone, for pelargonidin 47 and 140 ng/zone, and for delphinidin 171 and 513 ng/zone. With HPTLC the LOD and LOQ for cyanidin were 107 and 321 ng/zone, for keracyanin 189 and 566 ng/zone, and for pelargonidin 161 and 484 ng/zone (delphinidin was not detectable). Consequently, quantification of anthocyanes in the alimentary products by TLC allowed identification of more target compounds and in a higher number of alimentary products than by HPTLC. (Note that original HPTLC method in J Chromatogr A 1299 (2013) 105-118 was reported to be more sensitive (mainly 3-50 ng/zone) and with higher correlation coefficients of calibration curves (0.9993-0.9999) for 11 anthocyanins/-cyanidins than the HPTLC method that was reproduced in this paper.)

Trends Anal. Chem. 102, 225-235 (2018). The study described reliable effect-based methods for screening of endocrine disrupting compounds to fulfill the requirements of the European Decision EU 2015/495 regarding steroidal estrogens of the Water Framework Directive. The study identified TLC-based methods such as the planar Yeast Estrogen Screen (pYES) for the quantification of the overall estrogenic activity present in the sample by means of 17ß-estradiol-equivalence concentrations.

J. Planar Chromatogr. 31, 243-249 (2018). HPTLC of diazinon (1) and chlorpyrifos (2) in the leave extracts of lavender and rosemary on silica gel with petroleum ether – ethanol – glacial acetic acid 95:5:1 for (1) and 90:10:1 for (2). Quantitative determination by absorbance measurement at 254 nm. The hRf values for (1) and (2) were 54 and 50, respectively. Linearity was in the range of 10-1600 ng/zone for (1) and 40-2000 ng/zone for (2). The intermediate precision was below 2 % (n=3). The LOD and LOQ were 3 and 10 ng/zone for (1) and 12 and 40 ng/zone for (2), respectively. Average recovery was 100.8 % for (1) and 99.9 % for (2).

methanolic fraction. J. Planar Chromatogr. 31, 327-331 (2018). HPTLC of caffeic acid (1), vanillic acid (2), and syringic acid (3) in O. corniculata L. methanolic fraction on silica gel with toluene ‒ ethyl acetate ‒ formic acid 7:3:1. Quantitative determination by absorbance measurement at 300 nm. The hRF values for (1) to (3) were 36, 44 and 54, respectively. Linearity ranged between 100-700 ng/zone. LOD and LOQ were 40 and 100 ng /zone, respectively. The intermediate precision was <2 % (n=3). Recovery was between 97.1 and 99.6 %.

J. Planar Chromatogr. 31, 332-336 (2018). HPTLC of β-sitosterol (1) and lupeol (2) in Saussurea lappa and Saussurea auriculata on silica gel with toluene ‒ ethyl acetate ‒ glacial acetic acid 29:9:2. Detection by spraying with anisaldehyde–sulfuric acid reagent. Quantitative determination by absorbance measurement at 525 nm. The hRf values for (1) and (2) were 71 and 88, respectively. Linearity was between 100 and 400 ng/zone. LOD and LOQ were 7 and 23 ng for (1), and 6 and 17 ng for (2), respectively. The intermediate precision was <2 %. Average recovery was 99.9 % for (1) and 100.0 % for (2).

J. Planar Chromatogr. 31, 489-495 (2018). HPTLC of abacavir sulfate (1), lamivudine hydrochloride (2), and dolutegravir sodium (3) on silica gel with ethyl acetate ‒ ethanol ‒ acetone ‒ ammonia 2239:370:250:75. A factorial design was utilized to aid in method development and optimization. Quantitative determination by absorbance measurement at 267 nm. The hRF values for (1) to (3) were 65, 34 and 26, respectively. Linearity ranged between 4.8-14.4 μg/zone for (1), 2.4-7.2 μg/zone for (2) and 0.4-1.2 μg/zone for (3). LOD and LOQ were 997 ng/zone and 3022 ng/zone for (1), 254 ng/zone and 771 ng/zone for (2), and 100 ng/zone and 304 ng/zone for (3), respectively. The intermediate precision was <2 % (n=3). Recoveries were found in the range of 98.1–101.0 % for (1), 98.3–100.00 % for (2), and 98.5–101.3 % for (3), respectively._x000D_