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Multidimensional TLC procedure for separation of complex natural mixtures spanning a wide polarity range; Application for fingerprint construction and for investigation of systematic relationships within the Peucedanum genus

Cieśla Ł., Skalicka-Woźniak K., Hajnos M., Hawrył M., Waksmundzka-Hajnos M.

Acta Chromatographica

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2009

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Vol. 21, no. 4

641--657

EN

Identification of closely related plant species is not a trivial task, and is often difficult on the basis of morphological or anatomical features. To differentiate among analyzed species, a chromatographic fingerprint is usually constructed. This is not easy for very complex samples, however, especially those containing substances spanning a wide polarity range. In such circumstances more than one fingerprint is constructed, e.g. one for polar and the other for apolar constituents. In this paper a new method has been used for resolution of a mixture of 17 coumarins and flavonoids and, subsequently, construction of a fingerprint of closely related species belonging to the Peucedanum genus. This is the first time multidimensional planar chromatography has been applied for such purpose. Distinctive fingerprints are produced for every analyzed plant species, without the need to construct two fingerprints and without the application of more sophisticated multidimensional methods (e.g. hyphenation of HPLC and TLC, HPLC-MS, etc).

2

Identification of similar and orthogonal chromatographic thin-layer systems for two-dimensional separations of flavonoids and their analogues

Daszykowski M., Hawrył M., Waksmundzka-Hajnos M., Walczak B.

Acta Chromatographica

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2008

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Vol. 20, no. 3

283-307

EN

In this paper a broad overview of the retention behaviour of twenty flavonoids and their analogues in 74 TLC systems is reported. The compounds were chromatographed on different stationary phases (non-polar and polar-bonded stationary phases - wettable RP18W, silica, and aminopropyl-modified and diol-modified plates) developed with a variety of binary mobile phases (aqueous and non-aqueous). The chemometric techniques principal component analysis and hierarchical clustering were used to evaluate similarities and differences among the chromatographic systems. For selection of the most suitable systems either to perform two-dimensional separation or to enhance overall resolution by merging two stationary phases, indices scoring the separating power of a given system or pair of systems were applied. When separation of all pairs of chromatographic systems was evaluated with the index considered, the theoretical separation achieved in these systems could be visualized as a colour map. This colour map enabled rapid examination of resolution and selection of orthogonal systems enabling acceptable separation of the compounds. On the basis of the colour map it was found that relatively efficient two-dimensional separation of the compounds could be achieved on amino-modified plates developed using 9:1 tetrahydrofuran-water in the first dimension then 9:1, 4:1, 3:1, or 7:3 acetonitrile-water in the second dimension. Theoretically, the best separation could be achieved by combining diol-modified and amino-modified stationary phases and using 3:2 methanol-water and 9:1 acetonitrile-water, respectively, as mobile phases.

3

Selectivity of separation of heterocyclic bases in normal phase chromatographic systems

Waksmundzka-Hajnos M., Hawrył M., Hawrył A.

Chemia Analityczna

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1998

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Vol. 43, No. 4

561-574

EN

Selectivity of separation of heterocyclic bases - derivntives of pyridine, quinoline and acridine was investigated in different chromatographic systems using thin layers of silica, alumina and Florisil and several isoeluotropic eluents with polar modifiers such as: 2-propanol, dioxane, tetrahydrofuran, ethyl acetnte, ethylmethyl ketone, acetone, düsopropyl ether and dichloromethane diluted in n-heptane. The DRM values for chromatographed solutes in comparison to pyridine were calculated to choose the systems with the best selectivity of separation. Also the correlation diagrams of RM I vs. RM II permit to compare properties of adsorbents examined in different eluent systems and permit to select the best systems for the separation of a particular group of substances.

PL

Zbadano selektywność rozdziela zasad heterocyklicznych - pochodnych pirydyny, chinoliny i akrydyny w różnych układach chromatograficznych na cienkich warstwach żelu krzemionkowego, tlenku glinowego i Florisilu przy użyciu. kilku eluentów izoeluotropowych ź modyfikatorami polarnymi jak: 2-propanol, dioksan, tetrahydrofuran, octan etylu, keton etylowo metylowy, aceton, eter diisopropylowy i dichlorometan rozpuszczonymi w n-heptanie. Wyliczono wartości DRM dla chromatografowanych pochodnych w stosunku do pirydyny, aby wybrać układy o najlepszej selektywności rozdzielania. Również diagramy korelacyjne RM I vs. RM II pozwalają na porównanie właściwości badanych adsorbentów w różnych układach eluentów i na znalezienie najlepszego układu do rozdziału konkretnej grupy zasad chinolinowych.

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Chromatography of plant extracts using plates with chemically bonded polar stationary phases

Wawrzynowicz T., Waksmundzka-Hajnos M., Hawrył M.

Chemia Analityczna

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1998

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Vol. 43, No. 4

703-710

EN

In the search of selective systems for separation of closely related compounds from complex mixtures the chromatography of fruit extracts of some species of Apiaceae family and Aloë was carried out. The precoated HPTLC-silica, cyano and diol plates were used. The comparison of densitograms shows the similarity of surface activity and the selectivity of adsorbents. Silica and diol-type layers may be used as complementary adsorbents. The influence of composition of mobile phase on the separability of furocoumarins was stated.

PL

W poszukiwaniu selektywnych układów do rozdzielenia związków o zbliżonej strukturze cząsteczkowej ze złożonych mieszanin naturalnych przeprowadzono chromatografę ekstraktów z nasion kilku gatunków rodziny Apiaceae i Alony. Stosowano wysokosprawne płytki pokryte żelem krzemionkowym, fazą cyjanową i diolową. Porównanie densytogramów wskazuje na stosunkowo niewielkie różnice w selektywności adsorbentów. Gcl krzemionkowy i fazy diolowe mogą być stosowane komplementarnie w chromotografii polarnych związków. Stwierdzono, że nie tylko siła elucyjna eluentów a także ich skład decydują o rozdzielczości.