J. Planar Chromatogr. 15, 223-225 (2002). HPTLC of sanguinarine on silica gel, prewashed, using butanol - acetic acid - water 12:3:5. Quantitation by densitometry at 366 nm/>400 nm in fluorescence/reflectance mode. New rapid and reliable TLC procedure.

Proc. Intern. Symp. on Planar Separations Plan. Chrom. 243-249 (2003). TLC of alkaloids on silica gel and diol-, cyano-, amino-, and RP-18 modified silica gel with ethyl acetate - methanol - water 100:13.5:10 (I), ethyl acetate - methanol - water - acetic acid 100:2.7:5:3 (II), ethyl acetate - methanol - water - formic acid 100:2.7:5:3 (III), and ethyl acetate - iso-propanol - NH3 100:2:1 (IV) as mobile phases for silica gel and aqueous mobile phase containing methanol and ammonia for RP-chromatography in a horizontal developing chamber with sandwich configuration. 2-D TLC was performed on silica gel with (II) in the first direction and, after drying, with (III) in the second direction. Detection with Dragendorff or iodine reagent.

J. Planar Chromatogr. 17, 14-17 (2004). HPTLC of oxindole alkaloids on silica gel, Diol-, CN-, NH2-, and RP-18-phases. Normal-phase TLC with 1) ethyl acetate - methanol - water 200:27:20; 2) ethyl acetate - methanol - water - acetic acid 100:2.7:5:3; 3) ethyl acetate - methanol - water - formic acid 100:2.7:5:3; 4) ethyl acetate - isopropanol - ammonia 100:2:1. RP TLC with water - methanol 7:3 containing 0.25 % ammonia; development in horizontal chamber (sandwich configuration) at room temperature. Two-dimensional TLC with mobile phase 2 in the first direction and, after drying, with mobile phase 3 in the second direction. Evaluation under UV 254 nm and after derivatization with iodine reagent or with Dragendorff reagent. TLC separations were documented by scanning. Silica and cyanopropyl layers with acidic aqueous mobile phases gave the best separation.

Pharmazie 61, 483-485 (2006). Preparative and analytical TLC of talatisamine, 14-O-acetyltalatisamine, senbusine C, and condelphine on silica gel with toluene - ethyl acetate - diethylamine 9:2:1, and 7:2:1; and chloroform - methanol - ammonia 5:3:1, detection under UV light.

Anal. Chim. Acta 566 (2), 157-166 (2006). Extraction of pyrrolizidine alkaloids from the alkalised crude extract of Symphytum cordatum (L.) W.K. roots as free tertiary bases and polar N-oxides by one-step liquid–liquid partitioning and pre-fractionation by preparative multiple-development TLC on silica gel with chloroform – methanol – 25 % ammonia 50:5:1. Three alkaloid fractions of different polarities were obtained which showed different retention on silica gel: the most polar N-oxides had the highest retention, the tertiary bases had medium retention, and diesterified N-oxides had the lowest retention. Purification of the former fraction, which was reduced into free bases by sodium hydrosulfite, by liquid-liquid partitioning on Extrelut-NT3 cartridge. Further analysis by HPLC – ion-trap MS.

26th IPGA Annual conference, 12 (2010). TLC of berberine in plant extracts and methanolic solutions of a commercially available herbal formulation on silica gel with n-butanol - acetic acid - water 14:3:4. Densitometric evaluation at 435 nm. The method was found to be linear in the range of 8.1-26.9 ng/band. The proposed method was applied to the analysis of different formulations using berberine as chemical marker.

CBS 116, 13-15 (2016). HPTLC of nicotine in e-liquids on silica gel with chamber saturation (with filter paper) for 20 min with toluene – acetone –diethylamine 10:10:1 to the migration distance of 70 mm. Detection under UV 254 nm. Quantitative determination by absorbance measurement at 260 nm. Elution of the zones with methanol (with 0.1 % formic acid) into a single quadrupole MS and detection in positive ionization mode. The hRf value of nicotine was 56 and separation from other ingredients (propylene glycol, glycerol, flavors) was good. Visual evaluation of the samples for presence of nicotine was confirmed with MS and UV spectra.

J. Planar Chromatogr. 30, 142-147 (2017). 2D-HPTLC of eleven alkaloids: allocryptopine (1), berberine (2), boldine (3), chelidonine (4), glaucine (5), papaverine (6), emetine (7), columbamine (8), magnoflorine (9), palmatine (10), and coptisine (11) on bilayer Multi-K CS5 with methanol – water 4:1 containing 0.05 mL (volume not clear) diethylamine in the first dimension, followed by drying at 110 ºC for 40 min and developing in the second dimension with methanol – acetone – diisopropyl ether – ammonia 18:18:63:1. Quantitative determination at UV 366 nm. The LOD and LOQ were 25 and 63 μg/zone for (2), 14 and 42 μg/zone for (9).