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On-Column Ion-Exchange Preconcentration of Inorganic Anions in Open Tubular Capillary Electrochromatography with Elution Using Transient-Isotachophoretic Gradients. 3. Implementation and Method Development

Citation

Breadmore, MC and Palmer, AS and Curran, MAJ and Macka, M and Avdalovic, N and Haddad, PR, On-Column Ion-Exchange Preconcentration of Inorganic Anions in Open Tubular Capillary Electrochromatography with Elution Using Transient-Isotachophoretic Gradients. 3. Implementation and Method Development, Analytical Chemistry, 74, (9) pp. 2112-2118. ISSN 0003-2700 (2002) [Refereed Article]

DOI: doi:10.1021/ac011217u

Abstract

A solid-phase extraction method based on an ionexchange retention mechanism has been used for in-line preconcentration of inorganic anions prior to their separation by capillary electrophoresis (CE). A single capillary containing a preconcentration and a separation zone has been used in a commercial CE instrument without instrumental modification. Analyte anions were retained on a preconcentration zone comprising an adsorbed layer of cationic latex particles, while separation was achieved in a separation zone comprising fused silica modified by adsorption of a cationic polymer. Elution of the adsorbed analytes was achieved using an eluotropic gradient formed by a transient isotachophoretic boundary between a fluoride electrolyte and a naphthalenedisulfonate electrolyte. Optimization of the electrolyte concentrations, sample injection times, and back-flushing times allowed the successful separation of sub-ppb levels of inorganic anions using a 100-min injection at 2 bar pressure, introducing over 40 capillary volumes of sample. A method based on a 10-min injection allowed a 100-fold increase in sensitivity over conventional hydrodynamic injection for Br-, I-, NO3 -, CrO4 2-, and MoO4 2- with a total analysis time of 25 min. Detection limits were dependent on the injection time but were in the range 2.2-11.6 ppb for a 10-min injection time. This approach was used to determine NO3 - in Antarctic ice cores where the analysis could be performed using a sample volume 100 times less than that used for ion chromatography.

Item Details

Item Type:Refereed Article
Research Division:Chemical Sciences
Research Group:Analytical Chemistry
Research Field:Separation Science
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Chemical Sciences
Author:Breadmore, MC (Professor Michael Breadmore)
Author:Palmer, AS (Dr Anne Palmer)
Author:Macka, M (Professor Mirek Macka)
Author:Haddad, PR (Professor Paul Haddad)
ID Code:26114
Year Published:2002
Web of Science® Times Cited:82
Deposited By:IASOS
Deposited On:2002-08-01
Last Modified:2009-11-18
Downloads:0

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