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Modulation of the separation selectivity of inorganic anions in electrostatic ion chromatography using acidic eluents

Citation

Hu, W and Haddad, PR and Tanaka, K and Hasebe, K, Modulation of the separation selectivity of inorganic anions in electrostatic ion chromatography using acidic eluents, The Analyst, 125, (2) pp. 241-244. ISSN 0003-2654 (2000) [Refereed Article]

DOI: doi:10.1039/a909684a

Abstract

The separation selectivity for inorganic anions in electrostatic ion chromatography (EIC) was modulated by control of the concentration of H+ in the eluent. For example, in the separation of NO2 -, Br- and NO3 using H2SO4 as eluent, the elution order could be NO2 - < Br- < NO3 -; Br- < NO2 - < NO3 -; or Br- < NO3 - < NO2 -, depending on the concentration of H2SO4 in the range 1-30 mM. This behaviour is explained by protonation of the sulfonate functional groups of the stationary phase and the resultant changes in the binary electrical double layer (EDL) established at the charge centres of the zwitterionic stationary phase. The elution order for analyte anions was governed by the balance between the cation-EDL and anion-EDL, which is determined by the concentration of H+ in the eluent and results in varying degrees of ion-exchange contributing to a mixed-mode retention mechanism. It was also found in this study that addition of a small amount of perchlorate ion into the eluent was an effective means to elute very polarizable anions (e.g., I-, and SCN-). This was attributed to the high propensity for ClO4 - to enter the anion-EDL on the positively charged quaternary ammonium groups of the zwitterionic stationary phase.

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:Hu, W (Mr Wei Hu)
Author:Haddad, PR (Professor Paul Haddad)
Author:Tanaka, K (Dr Kazuhiko Tanaka)
ID Code:19319
Year Published:2000
Web of Science® Times Cited:12
Deposited By:Chemistry
Deposited On:2000-08-01
Last Modified:2011-08-04
Downloads:0

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