J. Planar Chromatogr. 13, 457-462 (2000). TLC and HPTLC of extracts and standards (quinine, quinidine, cinchonine, cinchonidine) on silica gel with 7 different mobile phases. The quaternary mobile phase toluene - chloroform - diethyl ether - diethylamine 8:3:7:2 enabled the determination of alkaloids in a variety of preparations and extracts. Two different modes of densitometric evaluation (absorbance and fluorescence) were used. Results from quantitative analysis were statistically assessed by use of a calibration procedure, a calibration equation, the correlation coefficient, and the relative standard deviation.

J. Planar Chromatogr. 14, 364-370 (2001). TLC of 24 alkaloids (aconitine - yohimbine) on silica gel and aminopropyl-modified silica gel plates as well as on cyanopropyl-, diol- and RP 18-modified silica gel plates using a variety of binary mobile phases prepared from n-hexane and polar modifiers - 2-propanol, ethyl acetate, methyl ethyl ketone, tetrahydrofuran, dioxane - in different concentrations for NP chromatography and reversed-phase systems with buffered aqueous -acetonitrile mobile phases (pH 9.15). Visualization at 254 nm.

Proc. Intern. Symp. on Planar Separations Plan. Chrom. 285-289 (2003). One-dimensional TLC of 8 quinolizidine alkaloids (sparteine, a-isosparteine, retamine, hydroxylupanine, cytisine, methylcytisine, sophocarpine, lupanine) on silica gel with hexane - diethyl amine 100:0 to 1:1, on silica gel and DIOL with chloroform - methanol - NH3 100:0:1, 95:5:1 to 85:15:1, and on DIOL and RP-18 with acetonitrile - water - hydrochloric acid 30:100:5, 30:100:10, 30:100:15 and 30:100:20.. 2D-TLC on DIOL with chloroform - methanol - NH3 85:15:1 (I) in the first direction and after drying at room temperature with acetonitrile - water - hydrochloric acid 30:100:7 (II) in the second direction. In adsorbent TLC - diol plates were used in the first direction with mobile phase I. Then the alkaloids were transferred by a specially designed device on the second RP-18 plate with the mobile phase II. The same phase was then used for the second development in the perpendicular direction. Visualization by spraying with Dragendorff reagent and documentation by photography.

CBS 82, 12-15 (1999). HPTLC of ergometrine, ergotamine, and ergocryptine on silica gel with dichloromethane - methanol 9:1 with chamber saturation. Quantification by fluorescence measurement at 245/>310 nm.

growing in Egypt. Phytochemistry. 65, 2113-2118 (2004). HPTLC of (-)-amarbellisine in the bulbs of Amaryllis belladona L. on silica gel with chloroform – methanol 9:1 with 1 drop of ammonia. Quantitative determination at 254 nm to estimate the alkaloidal content in the flowering stage (in April), and in the preflowering stage (in November).

Indian Drugs 45(3), 222-225 (2008). HPTLC of atisine in Aconitum heterophyllum (Ranunculaceae) on silica gel with toluene - ethyl acetate - diethylamine 7:2:1. Absorbance measurement at 274 nm prior to derivatization. Detection by dragendorff’s reagent followed by treatment with 10 % sodium nitrite. Quantitative determination by absorbance measurement at 520 nm. Linearity was between 10-60 ng/spot.

Journal of Pharmacy Research 2(12), 1893-1899 (2009). HPTLC of vasicine and vasicinone in methanolic aqueous extracts of the dried herb and in cough syrup on silica gel with chloroform - methanol 9:1. The hRf value of vasicine was 11 and of vasicinone 45. Densitometric quantification at 280 nm. The method was linear in the range of 2-100 ng/band for vasicine and 25-1000 ng/band for vasicinone. The recovery was 95-102 %. The limit of detection of vasicine was 1 ng and of vasicinone 25 ng. Vasicine and vasicinone were well separated from other constituents of Adhatoda vasica.

J. Planar Chromatogr. 28, 373-379 (2015). TLC of trigonelline in the seeds of Trigonella foenum-graecum on silica gel with acetonitrile - methanol - water 3:2:1. Quantitative determination by absorbance measurement at 265 nm. The hRF value for trigonelline was 19. Linearity was in the range of 100-2000 ng/zone. LOD and LOQ were 2 and 7 ng/zone. The intermediate precision was below 0.8 % (n=3). Average recovery was 99 %. Comparable results were obtained with a validated HPLC method.