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001-es BibID:	BIBFORM085420
Első szerző:	Elek János (vegyész)
Cím:	Enantio selective capillary electrophoretic separation of tryptophane- and tyrosine-methylesters in a dual system with a tetra-oxadiaza-crown-ether derivative and a cyclodextrin / Janos Elek, Debby Mangelings, Timea Ivanyi, Istvan Lazar, Y. Vander Heyden
Dátum:	2005
ISSN:	0731-7085
Megjegyzések:	Different dual selector systems containing a cyclodextrin derivative (methyl-?-cyclodextrin and dimethyl-?-cyclodextrin) and a new diaza-crown-ether derivative (N-[2-(1,4,10,13-tetraoxa-7,16-diazacyclooctadecan-7-yl)propanoyl]glycine) were studied in the enantioselective separation of tryptophan-methylester and tyrosine-methylester enantiomers. This paper deals with the systematic study of the effects of changing the composition of the background electrolyte on the resolution of the d- and l- forms using an experimental design approach. It was found that the dual systems allowed a better chiral separation of the amino acid derivatives. The experimental design approach also allowed improving the separation compared to the starting conditions (center point of the design), which were adopted from a previous study.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk Chiral separation Dual selector systems Diaza-crown-ether Response surface methodology Experimental design
Megjelenés:	Journal of Pharmaceutical and Biomedical Analysis. - 38 : 4 (2005), p. 601-608. -
További szerzők:	Mangelings, Debby Iványi Tímea (vegyész) Lázár István (1959-) (vegyész) Heyden, Yvan Vander
Pályázati támogatás:	T032100 OTKA
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM096826
Első szerző:	Forlay-Frick, Peter
Cím:	Newly synthesized tetraoxa-diaza crown ether derivatives versus commercialized crown ethers in the separation of positional isomers with capillary electrophoresis / Peter Forlay-Frick, Debby Mangelings, Tímea Iványi, István Lázár, Károly Héberger, Yvan Vander Heyden
Dátum:	2006
ISSN:	0731-7085
Megjegyzések:	Three new tetraoxa-diaza derivatives of 1,4,10,13-tetraoxa-7,16-diazacyclo-octadecane (R-1, R-2 and R-3) and three commercially available crown ethers, 18-crown-6 (18C6), (+)-18-crown-6-tetracarboxilic acid (18C6H4) and 1,4,10,13-tetraoxa-7,16-diazacyclo-octadecane, were investigated to separate the positional isomers of aminophenol, aminobenzoic acid and aminocresol. The running electrolyte, in which the crown ethers were dissolved, was a 50 mM Tris solution adjusted to pH 2.0 with hydrochloric acid. Using 50 mM H3PO4 buffer, whose pH was adjusted to 2.0 with Tris, or only hydrochloric acid solution with the same pH, did not allow good separations for the tested components. The effect of the crown ether concentration on the separation of the 11 positional isomers was studied in the concentration range of 10-50 mM. The best separations were achieved using the 18C6 and the 18C6H4 crown ethers: 9 isomers out of 11 could be separated within one run. The m- and p-aminophenol isomers could not be separated under the investigated experimental conditions. The newly synthesized tetraoxa-diaza crown ether derivatives were only found suitable for the separation of aminobenzoic acid positional isomers. The macrocyclic ring of the tetraoxa-diaza crown ethers was not able to form a stable inclusion complex with the tested positional isomers. Consequently, the aminophenol and aminocresol isomers were not separated, the isomers migrated with the same or very similar velocities.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk Capillary electrophoresis Positional isomers Crown ethers Tetraoxa-diaza crown ethers Aromatic amines
Megjelenés:	Journal Of Pharmaceutical And Biomedical Analysis. - 41 : 4 (2006), p. 1164-1170. -
További szerzők:	Mangelings, Debby Iványi Tímea (vegyész) Lázár István (1959-) (vegyész) Héberger Károly Vander Heyden, Yvan
Pályázati támogatás:	T-32100 OTKA T-037684 OTKA
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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