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Wyszukujesz frazę "micellar liquid chromatography" wg kryterium: Temat


Wyświetlanie 1-3 z 3
Tytuł:
Relationship between micellar liquid chromatography retention of sulfonamides and the pH and concentration of surfactants and organic modifiers in the mobile phase
Autorzy:
Szymański, A.
Powiązania:
https://bibliotekanauki.pl/articles/347039.pdf
Data publikacji:
2011
Wydawca:
Politechnika Bydgoska im. Jana i Jędrzeja Śniadeckich. Wydział Technologii i Inżynierii Chemicznej
Tematy:
micellar liquid chromatography
retention mechanism
sulfonamides
Opis:
The paper presents an attempt to adapt a retention model suggested and verified by classic RP LC in micellar liquid chromatography, MLC. Instead of hydrophobic interactions with ODS groups and electrostatic interactions with silanol residues in C-18 packing, hydrophobic interactions with alkyl groups and ionic interactions with anionic moieties of the SDS-modified stationary phase were considered. Due to the different characteristics of the stationary phase in the MLC depending on the pH of the mobile phase, the equation used to determine the contribution of electrostatic interactions to retention was modified. Theoretical curves for the relationship between retention and SDS micelle concentration in the mobile phase, organic modifier concentration and eluent pH were determined. For comparison, curves based on data obtained in basic sulfonamide studies were plotted in the same coordinate systems and units. A complete qualitative similarity was noted between the theoretical curves predicting retention changes with changing micellar mobile phase parameters and the curves determined based on experimental results for the sulfonamides. The qualitative similarity involves a similar shape of the respective curves and identical tendencies. In general, a larger reduction of sulfonamide retention with respect to the predicted value is noted. The deviation results from changes in the sulfonamide property with changing pH of the mobile phase.
Źródło:
Ars Separatoria Acta; 2011, 8; 51-67
1731-6340
Pojawia się w:
Ars Separatoria Acta
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Retention mechanism of sulfonamides in micellar reversed phase liquid chromatography
Autorzy:
Szymański, A.
Powiązania:
https://bibliotekanauki.pl/articles/347037.pdf
Data publikacji:
2011
Wydawca:
Politechnika Bydgoska im. Jana i Jędrzeja Śniadeckich. Wydział Technologii i Inżynierii Chemicznej
Tematy:
micellar liquid chromatography
quantitative structure-activity relationships
sulfonamides
Opis:
A mechanism of retention of sulfonamides in the micellar liquid chromatography, based on similar models verified for other compounds, was proposed. The magnitudes of hydrophobic and electrostatic interactions of sulfonamides were estimated for different concentrations of surfactant in the mobile phase and at varied pH. With increasing SDS concentrations and at a constant pH, a decrease in the hydrophobic interaction intensity was noted. When pH is varied, the values of the constant, describing the hydrophobicity of the sulfonamides, remained at an approximately same level (taking into account the standard deviation values). Greater differences were observed in the constants related to the electrostatic interactions informing about the increase or decrease in retention, following from ionic interactions. For each sulfonamide, the molar fraction of the ionic fractions present in the mobile phase was calculated from the formula derived, which permitted determination of the type of electrostatic interactions, varying with the eluent’s changing pH. On the basis of the chromatographic data collected, it was established that retention of sulfonamides in the SDS micellar system depends on the hydrophobic and electrostatic interactions. For varied pH values, the hydrophobic interactions of sulfonamides did not change significantly, all changes in the retention of the sulfonamides were attributed to changes in the electrostatic interactions.
Źródło:
Ars Separatoria Acta; 2011, 8; 69-80
1731-6340
Pojawia się w:
Ars Separatoria Acta
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sole sodowe kwasów cholowych jako chiralne modyfikatory fazy ruchomej w układzie wysokosprawnej chromatografii cieczowej
Bile acid sodium salts as chiral modifiers of mobile phase in high performance liquid chromatography
Autorzy:
Kowalczyk, M.
Asztemborska, M.
Powiązania:
https://bibliotekanauki.pl/articles/92352.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Przyrodniczo-Humanistyczny w Siedlcach
Tematy:
pochodne binaftyli
rozdzielenie chiralne
cholan sodowy
deoksycholan sodowy
chiralne fazy ruchome
micelarna chromatografia cieczowa
binaphthyl derivatives
chiral separation
sodium cholate
sodium deoxycholate
chiral mobile phases
micellar liquid chromatography
Opis:
W pracy opisano zastosowanie cholanu sodu i deoksycholanu sodu, jako modyfikatorów fazy ruchomej w wysokosprawnej chromatografii cieczowej. Własności enancjoseparacyjne micelarnych faz chiralnych dla optycznie czynnych pochodnych binaftyli: fosforanu- 1,1’- -binaftylo-2,2’-diylu oraz 1,1’-binaftylo-2,2’-diolu. Zbadano proces adsorpcji cholanu i deoksycholanu sodu na fazie C18. Zbadano wpływ stężenia i typu surfaktantu, jak również rodzaj i stężenie dodatku organicznego (n-alkohol) na proces rozpoznania chiralnego przez badane układy micelarne.
In the paper the application of sodium cholate and sodium deoxycholate as modifiers of mobile phase in high performance liquid chromatography was described. Enantioseparation properties of micellar chiral phases were studied for optically active derivatives of binaphthyls: 1,1'-binaphthyl-2,2'-diyl hydrogenphosphate and 1,1'-binaphthalene-2,2'-diol. The process of adsorption of sodium cholate and sodium deoxycholate on C18 phase was studied. The influence of type and concentration of surfactant as well as type and concentration of organic additive (n-alcohol) on process of chiral recognition was investigated. It has been found that enantiorecognition of bile salts micelle increase with the increase of the chain length of n-alcohol.
Źródło:
Camera Separatoria; 2011, 3, 1; 161-184
2083-6392
2299-6265
Pojawia się w:
Camera Separatoria
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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