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Analysis of alkaloids from different chemical groups by different liquid chromatography methods

100%
Petruczynik A.
Open Chemistry
|
2012
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vol. 10
|
issue 3
802-835
EN
Alkaloids are biologically active compounds widely used as pharmaceuticals and synthesised as secondary methabolites in plants. Many of these compounds are strongly toxic. Therefore, they are often subject of scientific interests and analysis. Since alkaloids - basic compounds appear in aqueous solutions as ionized and unionized forms, they are difficult for chromatographic separation for peak tailing, poor systems efficiency, poor separation and poor column-to-column reproducibility. For this reason it is necessity searching of more suitable chromatographic systems for analysis of the compounds. In this article we present an overview on the separation of selected alkaloids from different chemical groups by liquid chromatography thus indicating the range of useful methods now available for alkaloid analysis. Different selectivity, system efficiency and peaks shape may be achieved in different LC methods separations by use of alternative stationary phases: silica, alumina, chemically bonded stationary phases, cation exchange phases, or by varying nonaqueous or aqueous mobile phase (containing different modifier, different buffers at different pH, ion-pairing or silanol blocker reagents). Developments in TLC (NP and RP systems), HPLC (NP, RP, HILIC, ion-exchange) are presented and the advantages of each method for alkaloids analysis are discussed. [...]
2
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Retention, separation selectivity and system efficiency of selected basic psychotropic drugs on different RPLC columns

51%
Petruczynik A., Wróblewski K., Dzioba K., Waksmundzka-Hajnos M.
Open Chemistry
|
2015
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vol. 13
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issue 1
EN
Retention parameters of psychotropic drug standards were determined on different columns, i.e., Octadecyl silica, Phenyl, Phenyl-Hexyl, Polar Reverse Phase, Pentafluorophenyl, and Cyanopropyl using aqueous eluent systems containing methanol or acetonitrile as organic modifiers, acetate buffer at pH 3.5 and addition of silanol blocker − diethylamine (DEA). The retention, separation selectivity, and sequence of elution were different when using eluents containing various organic modifiers. The significant differences were observed in retention parameters with a change of the used stationary phase. The various properties of stationary phases resulted in differences in analyte retention, peaks shape, systems efficiency and separation selectivity. The best shape of peaks were on Cyanopropyl (CN) column and the highest efficiency for most investigated psychotropic drugs were obtained on Phenyl-Hexyl and Polar RP columns.
3
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Retention behavior of selected alkaloids in Reversed Phase micellar chromatographic systems

51%
Petruczynik A., Noster G., Waksmundzka-Hajnos M.
Current Issues in Pharmacy and Medical Sciences
|
2015
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vol. 28
|
issue 2
126-130
EN
In this work, the effects of sodium dodecyl sulfate (SDS) concentrations on retention, separation selectivity, peak shapes and systems efficiency were investigated. Herein, the retention data for 11 alkaloids were determined on an RP18 silica column with mobile phases containing methanol as organic modifier, with acetate buffer at pH 3.5, and, subsequently, with the addition of sodium dodecyl sulfate (SDS). The results of this study indicate that the retention of alkaloids decreases with the increase of SDS concentration in the mobile phase. The increase of SDS concentration, however, leads to the significantly improvement of peak symmetry and the increase of theoretical plate number in all cases. The best system efficiency for most of the investigated alkaloids was obtained in a mobile phase containing 0.1 M SDS, while most symmetrical peaks were obtained through the addition of 0.3 M of SDS to the mobile phase.
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