J. Planar Chromatogr. 28, 144-151 (2015). TLC of L-cysteine on cellulose phase with 2-butanol - pyridine - glacial acetic acid - water 5:10:3:12. Just before development an equimolar amount of (1) manganese(II) acetate or (2) zinc(II) nitrate was added to the sample solutions. Detection in reflectance mode at 485 nm, concentration of L-cysteine and DL-cysteine in 70 % aqueous acetonitrile was 0.7 mg/mL. Developing distance was 7 cm, development time ca. 3 h. Derivatization by spraying with 0.5 % ninhydrin solution in 2-propanol, followed by heating for 5 min at 110 °C. The experiments demonstrate the spontaneous chiral conversion and spontaneous peptidization of L-cysteine, and the enantioseparation of L-cys and D-cys enantiomers is facilitated by chelating the transition metal cation (e.g. Mn(II)) with the cys ligands.

CBS 116, 2-4 (2016). HPTLC of steroid alkaloid saponins from potato sprouts on silica gel with chloroform – methanol – water 60:40:9 with chamber saturation without filter paper over a migration distance of 70 mm. Detection by dipping half of the plate in anisaldehyde-sulfuric acid reagent, drying for 10 min and heating at 70 °C for 5 min. The other half of the plate was used for the blood-gelatin test: dipping in 0.5 % polyisobutylmethacrylate in n-hexane – chloroform 20:1 for 10 s, coating with 40 mL blood-gelatin (2 % gelatin in PBS buffer pH 7.4 with 3 % human blood preservation), storage for 12-48 h at 4 °C. Evaluation under UV 366 nm and white light. Semiquantitative evaluation of the hemolytic activity using the substance digitonin from potato sprouts. The hemolytic activity of α-chaconine was comparable to the effect of 16-20 µg digitonin.

Planta Medica 82(18), 1576-1583 (2016). The fractionation (by column and flash chromatography) of an aqueous extract of the aerial parts of Hilaria hirsuta was monitored through TLC on silica gel with n-butanol – acetic acid – water 13:3:5. The compounds (including flavonoids narcissin and rutin, and two new saponins, herniariasaponins G and H) were detected with anisaldehyde sulfuric acid reagent.

CBS 118, 9-12 (2017). Comparison of TLC and HPTLC methods for (1) an aqueous-ethanolic extract of kidney vetch, (2) suppositories containing caraway extract, aqueously fermented root extracts of (3) barberry and (4) Solomon’s seal, and standards quinine hydrochloride, hyperoside, caffeic acid, rutin, fructose, caffeic acid, and noscapine hydrochloride. HPTLC on silica gel for (1) with chloroform – methanol – water 14:6:1, (2) with ethyl acetate – anhydrous formic acid – water 21:2:2, (3) with ethyl acetate – anhydrous formic acid – water 8:1:1 and (4) with chloroform – methanol – water 25:21:4. Detection by spraying with a (1) solution of 20 % antimony(III) chloride in chloroform and heating at 105 °C for 30 min, (2) 1 % methanolic solution of diphenylborinic acid 2-aminoethyl ester (natural products reagent), followed by a 5 % methanolic polyethylene glycol (macrogol) 400 solution and detection at UV 366 nm after 30 min, (3) bismuthate reagent (mixture of 0.85 g alkaline bismuth nitrate, 40 mL water, 10 mL acetic acid, and 20 mL potassium iodide solution (400 g/L), glacial acetic acid and water, 1:2:10), and (4) 1:1 mixture of 5 % sulfuric acid in ethanol and 2 % vanillin in ethanol and heating for 15 min at 105 °C. Compared to TLC, by HPTLC developing times were decreased, the separation power was higher and zones were sharper.

Proc. 6th Int. Symp. Instrum. Planar Chromatogr., (Interlaken 1991), Inst. Chromatogr., Bad Dürkheim, FRG, 49-55 (1991). Separation of ceramides and cholesterol on silica, using a four-step 2-D developing technique: first direction with chloroform - acetone - methanol 90:5:5 over 1 cm, second direction with the same solvent over 8.5 cm, then in the first direction again with chloroform - acetone - methanol - NH3 60:30:8:2, and finally with chloroform - acetone - methanol - acetic acid - water 78:16:4:2:1 in the second direction. Derivatization by dipping in phosphoric acid - acetic acid - sulfuric acid - water 10:10:1:180 followed by heating at 200 °C for 10 min. Method for routine analysis of ceramides.

J. Planar Chromatogr. 3, 160-162 (1990). HPTLC of ß-escin, horse-chestnut fluid and spray-dried extract samples on silica with propanol - ethyl acetate - water 4:3:3. Visualization by immersion of the dried plate for 2 s in a mixture of freshly prepared iron(III)chloride reagent - methanol 1:4. Densitometric evaluation was carried out by scanning in reflectance/absorbance mode at 540 nm. Excellent repeatability; (cv = 1.7%).

J. Planar Chromatogr. 4, 77-79 (1991). HPTLC of xylose, 3-o-methylglucose and rhamnose on silica with ethyl acetate – pyridine – acetic acid – water 75:15;10:10 (3 consecutive runs); detection by immersion in amino-benzoic acid reagent. Detection by densitometry in reflectance mode at 400 nm. Determination of method accuracy for 0.4 and 0.8 µg/4 µL of each monosaccharides (mean results of 20 replicate analyses are reported); CV = < 2.7%.

Pest. (Nongyao) 31, 31-32 (1992). TLC of mipcin (= o-cumenylmethylcarbamate) on silica with acetone – ethyl acetate 1:1. Detection by spraying with 1% potassium iodide – ethanol 5:2. Quantification by densitometry at 400 nm.