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Titolo:
SEPARATION OF URANIUM(VI) AND LANTHANIDES BY CAPILLARY ELECTROPHORESIS USING ON-CAPILLARY COMPLEXATION WITH ARSENATE-III
Autore:
MACKA M; NESTERENKO P; ANDERSSON P; HADDAD PR;
Indirizzi:
UNIV TASMANIA,DEPT CHEM,GPO BOX 252-75 HOBART TAS 7001 AUSTRALIA UNIV TASMANIA,DEPT CHEM HOBART TAS 7001 AUSTRALIA
Titolo Testata:
Journal of chromatography
fascicolo: 1-2, volume: 803, anno: 1998,
pagine: 279 - 290
Fonte:
ISI
Lingua:
ENG
Soggetto:
METAL-IONS; ZONE ELECTROPHORESIS; SENSITIVE DETERMINATION; COLUMN CHELATION; CHROMATOGRAPHY; EQUILIBRIA; ISOTACHOPHORESIS; STABILITY; BEHAVIOR; CATIONS;
Keywords:
COMPLEXATION; BACKGROUND ELECTROLYTE COMPOSITION; URANIUM; LANTHANIDES; ARSENAZO III;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
56
Recensione:
Indirizzi per estratti:
Citazione:
M. Macka et al., "SEPARATION OF URANIUM(VI) AND LANTHANIDES BY CAPILLARY ELECTROPHORESIS USING ON-CAPILLARY COMPLEXATION WITH ARSENATE-III", Journal of chromatography, 803(1-2), 1998, pp. 279-290

Abstract

The viability of the separation of lanthanides and uranium(VI) in theform of strongly absorbing complexes with arsenate III (AIII) was studied with the aim to increase the sensitivity of absorbance detection in determination of these metals by capillary electrophoresis (CE). Special attention was paid to the complexation equilibria in the background electrolyte (BGE). On-capillary complexation provided better peak shapes for lanthanides compared to pre-column complexation. While the BGE composition had very little effect on the peak shape of the kinetically inert uranium(VI) complex, it played a crucial role in the peak shapes of the kinetically labile lanthanide complexes. Addition of a second ligand competing with the metallochromic ligand AIII for the metal ions was found to be critical to achieve good peak shape. The nature and concentration of the competing complexing ligand added to the BGE, the pH, and the concentration of AIII were found to exert a strong influence on the separation selectivity, peak shapes and the detectionsensitivity. Several carboxylic acids were compared as BGE competing ligands and citrate provided best selectivity and peak shapes. A citrate BGE at pH 4.7 and containing 0.1 mM AIII was used for the separation of uranium(VI) (350 000 theoretical plates) and La-III (63 000 theoretical plates) while, to separate most lanthanides and uranium(VI), a similar BGE with a lower (0.03 mM) AIII concentration was used. Using hydrostatic sampling (100 mm for 10 a) detection limits of 0.35 mu M (49 ppb) La-III and 25 mu M (60 ppb) UO2 were obtained. Using on-capillary complexation, sample stacking was retained for injection times of up to at least 100 s (ca. 30-mm sample plug) without loss of peak shapes for lanthanides or recovery for La-III. When this process was used,the detection limit for La-III was reduced to about 5 ppb. Optimal properties of metallochromic ligands for separation and detection of metals by CE are discussed. (C) 1998 Elsevier Science B.V.

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Documento generato il 07/07/20 alle ore 22:26:23