Library Open Repository

On-column ion-exchange preconcentration of inorganic anions in open tubular capillary electrochromatography with elution using transient-isotachophoretic gradients. 3. Implementation and method development

Downloads

Downloads per month over past year

Breadmore, MC and Palmer, AS and Curran, M and Macka, M and Avdalovic, N and Haddad, PR (2002) 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

[img] PDF
280.pdf | Request a copy
Full text restricted
Available under University of Tasmania Standard License.

Abstract

A solid-phase extraction method based on an ion-exchange 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-, CrO42-, and MoO42- 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 Type: Article
Journal or Publication Title: Analytical Chemistry
Page Range: pp. 2112-2118
ISSN: 0003-2700
Identification Number - DOI: 10.1021/ac011217u
Additional Information: Copyright 2002 American Chemical Society
Date Deposited: 23 Apr 2008 12:20
Last Modified: 18 Nov 2014 03:39
URI: http://eprints.utas.edu.au/id/eprint/6218
Item Statistics: View statistics for this item

Repository Staff Only (login required)

Item Control Page Item Control Page