Anal. Bioanal. Chem. 412, 2633-2644 (2020). HPTLC of  cannabinol in sediment samples on silica gel with n-heptane - diethyl ether 9:1. Detection by spraying with cerium- molybdenum reagent (400 mg cerium IV sulfate and 20 g ammonium molybdate in 400 mL 10 % sulfuric acid). HPTLC plates were further analyzed by electrospray ionization mass spectrometry. The hRF value for cannabinol was 20. Linearity was between 25 and 155 ng/zone. Intermediate precision was below 5 % (n=3). The LOD and LOQ were 6 and 21 ng/zone. Average recovery was 73 %.

Foods 9(8), 1136 (2020). TLC of methanolic decoctions and ultrasonication extracts from Zingiber officinale (Zingiberaceae) rhizomes, as well as from commercial ginger formulations, on reverse-phase C18-silica gel with ethanol – water 13:7. Densitometry at 200 nm in absorbance and reflectance modes for 6-shogaol (SHO, hRF 36) and 6-gingerol (GIN, hRF 53). Standards of these vanilloid phenolics were also used for calibration; linearity was in the range of 100–700 ng for SHO and of 50–600 ng/band for GIN; interday and intra-day precisions were below 1.6 %. The LOD and LOQ was 34 and 101 ng for SHO, 17 and 51 ng for GIN, respectively. Recovery rates were 98.8–101.6 % for SHO and 99.0–101.5 % for GIN. For each extract, SHO and GIN levels were calculated, the yields after ultrasonication extraction were 10-25 % higher than with the corresponding decoctions. Comparison with other published methods (LC-MS and HPLC) showed superiority of this new method in terms of linearity range, accuracy and precision.

3 Biotech 10(8), 344 (2020). Rauvolfia serpentina (Apocynaceae) was cultivated in vitro as leaf-derived callus and as plantlet cultures obtained from tissues of nodal explants, without or with cadmium chloride as elicitor of alkaloid production. TLC of methanol – ammonia 10:1 extracts of callus and plantlet organs (leaves, stems and roots) on silica gel, along with indole alkaloids reserpine and ajmalicine in different concentrations. Development with chloroform – toluene – ethyl acetate – diethyl amine 7:7:4:1. Detection under UV light and by densitometry scanning in absorbance mode at 240 nm and 280 nm. The highest alkaloid yields were obtained for reserpine (hRF 15) in roots (191µg/g) and for ajmalicine (hRF 45) in callus (131µg/ml) when culture had been done with elicitor 0.15 mM for 6 days and 4 days, respectively (at 0.20 mM, an inhibiting effect was observed).

J. Planar Chromatogr. 20, 95-99 (2007). TLC of atrazine and simazine on silica gel with hexane - chloroform - acetone 12:5:3 with chamber saturation. Detection under UV light at 254 nm. Also quantitative evaluation. The genetic algorithm proved to be an optimization procedure which can be successfully applied to optimization of microwave-assisted extraction experiments. Application of recovery experiments from spiked soil.

Anal. Chim. Acta 624 (1), 1-15 (2008). Aminoglycosides and macrolides are important antibiotics for veterinary medicine and are widely used in the treatment of bacterial disease, and as feed additives for growth promotion. As a result the European commission set strict criteria for monitoring residues and requires testing for low levels of aminoglycosides and macrolides in foods. Therefore the development of fast, reliable, and sensitive methods for the extraction and subsequent analysis of these antibiotics is of great interest. The review discusses analytical methods for both extraction and determination of antibiotics in various food matrices focusing on the last 10 years. Extraction and clean-up methods such as deproteinization and solid-phase extraction are described, and various screening methods including TLC, EI, CE, microbiological assays, and LC combined with MS are reviewed.

Acta Chromatographica 20(4), 673-683 (2008). Presentation of a quantitative method for the analysis of lycopene in nutritional supplements consumed to reduce the risk of prostate cancer and other forms of cancer and cardiovascular disease. HPTLC on silica gel with petroleum ether – dichloromethane 9:1. Quantification by densitometry at 416 nm. Four products containing 300 µg, 3 mg, 5 mg, or 10 mg lycopene plus other ingredients were quantified using a lycopene standard: the measured amounts ranged from 77.7 to 98.1 % of the stated label values. The accuracy by spiked blank analysis was within 1.90 % of theoretical values for the 3 mg softgels and 1.10 % of theoretical values for the 10 mg softgels. The precision of replicate analyses showed a RSD of 1.44 % for the 10 mg softgels and 2.39 % RSD for the spiked blank for the 3 mg softgels. The results obtained for Lycopene standards available from two other companies showed 55.6, 57.6, and 20.0 % of the minimum amount expected from the stated label values.

CBS 114, 13-15 (2015). To test the new HTpSPE–TOFMS screening, TLC of a pesticide mixture (acetamiprid, azoxystrobin, chlorpyrifos, fenarimol, mepanipyrim, penconazole, pirimicarb) in several plant matrices (cucumber, tomato, grape, apple extracts) on amino layer pre-treated by dipping in 2 % formic acid solution in acetonitrile and drying for 10 min. Development with 10 mL acetonitrile, migration distance 75 mm, drying 5 min; second development in the backwards direction with 10 mL acetone, migration distance 45 mm, drying 3 min. Detection under UV 254 nm, UV 366 nm and white light. For HTpSPE and μL-flow injection analysis–TOFMS the target analyte zone was eluted with the TLC–MS Interface into autosampler vials with acetonitrile – 10 mM ammonium formate 1:1, flow rate 0.2 mL/min, Elution time was 60 s. An HPLC system was coupled via a PEEK capillary and a nano-electrospray ionization interface to a TOFMS without an analytical column. The mean recovery for a pesticide mixture spiked into fruit and vegetable extracts was between 86 % and 116 % with %RSDs of 1.5–10 % (n = 5).

J. Chromatogr. Sci. 55 (10), 1059-1065 (2017). Presentation of a new high-throughput method for the simultaneous analysis of isoflavones and soyasaponins in soy (Glycine max L.) products by HPTLC on silica gel with ethyl acetate – methanol – water – acetic acid 100:20:16:1. Detection by treatment with anisaldehyde sulfuric acid reagent. Quantitative determination by densitometric multi-wavelength scanning at UV 265 nm for genistin, daidzin and glycitin and at 650 nm for soyasaponins I and III. The correlation coefficient of the linear calibration curve was >0.994. Intra-day precision (%RSD) of substances in matrix was between 0.7-0.9 %, inter-day precision (%RSD) was between 1.2-1.8 %). The method was suitable for the determination of the studied analytes in soy-based infant formula and soybean products.