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Preparation and characterisation of dual-layer latex-coated columns for open-tubular capillary electrochromatographic preconcentration of cations combined in-line with their separation by capillary electrophoresis

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Zhang, SS and Macka, M and Haddad, PR (2006) Preparation and characterisation of dual-layer latex-coated columns for open-tubular capillary electrochromatographic preconcentration of cations combined in-line with their separation by capillary electrophoresis. Electrophoresis, 27 (5-6). pp. 1069-1077. ISSN 0173-0835

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Abstract

A dual-layer ion-exchange latex-coated column was prepared and characterised for on-capillary preconcentration of cations using an open-tubular ion-exchange CEC format. After preconcentration, the analyte cations were eluted with a transient isotachophoretic gradient and separated by CE. The latex double layer was established by first coating the negatively charged wall of the capillary with a layer of cationic quaternary ammonium anion-exchange Dionex AS5A latex particles (60 nm diameter), and then coating a layer of anionic sulphonated cation-exchange Dionex CS3 latex particles (300 nm diameter) onto the underlying AS5A layer. The adhesion of layers is based on electrostatic attractions. Several dual-layer capillaries were characterised for their EOF and ion-exchange capacity and this showed that coatings could be prepared reproducibly by a simple flushing procedure. The dual-layer columns exhibited a moderate, pH-independent EOF (ca. 26×10-9 m2 V-1s-1) and an ion-exchange capacity of 57 µequiv./g (or 2.69 nequiv./column). Using an 8 cm length of coated capillary combined with a 72 cm length of untreated capillary, a method for on-line preconcentration and separation of monovalent organic bases, alkali metal ions and alkaline earth metal ions by CE was developed. Recoveries for the preconcentration step were 48% for 4-methylbenzylammonium, 43% for benzylammonium, 30-32% for alkali metal ions and 71-75% for alkaline earth cations. In all cases, recoveries were reproducible with RSDs being less than 6.2%. The influences of the ion-exchange selectivity coefficient of the analyte and the sample-loading rate on analyte recovery were also examined. The proposed method was utilised for the determination of alkaline earth cations and low µM detection limits were obtained.

Item Type: Article
Keywords: Inorganic cations • Latex coatings • On-line preconcentration • Open-tubular capillary electrochromatography
Journal or Publication Title: Electrophoresis
Page Range: pp. 1069-1077
ISSN: 0173-0835
Identification Number - DOI: 10.1002/elps.200500674
Additional Information: The definitive published version is available online at: http://interscience.wiley.com
Date Deposited: 10 Sep 2008 04:56
Last Modified: 18 Nov 2014 03:50
URI: http://eprints.utas.edu.au/id/eprint/7549
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