A new and selective capillary column coated with cationic diazacrown ether for separation of organic and inorganic anions by capillary electrophoresis.
A new coated capillary has been introduced for capillary electrophoretic separation of anions by using a positively charged diazacrown ether with a 12-membered ring. A positive charge spread over the inner capillary surface led to a substantial anodic electroosmotic flow (EOF) over the range of migrating buffer of pH 2-11. Under the optimum conditions of 25 mM phosphate buffer at pH 7, the diazacrown-coated capillary showed a successful simultaneous separation of 7 inorganic anions and 13 aromatic anions (including positional isomers) in less than 15 min. The migration times of the sample anions and EOF marker for consecutive runs on a single column were highly reproducible, giving a relative standard deviation of 1%. Theoretical treatment of the migration behavior clearly demonstrated that ion association between the diazacrown and analyte anions is strongly dependent on the nature of the functional groups of anions (e.g., sulfonate groups > carboxyl groups) and the number of negative charges (e.g., trivalent anions > divalent anions > monovalent anions) on the analyte.
Mori
Masanobu
M
National Institute of Advanced Industrial Science and Technology at Seto, Seto, Japan.
Tsue
Hirohito
H
Department of Natural Resources, Graduate School of Global Environmental Studies, Kyoto University, Kyoto, Japan.
Tanaka
Shunitz
S
Division of Material Science, Graduate School of Environmental Earth Science, Hokkaido University, Sapporo, Japan.
Tanaka
Kazuhiko
K
National Institute of Advanced Industrial Science and Technology at Seto and Graduate School of Engineering, Chubu University, Seto, Japan.
Haddad
Paul
P
Australian Centre for Research on Separation Science, School of Chemistry, University of Tasmania, Hobart, Australia.
D000838:Anions; D002412:Cations; D043844:Crown Ethers / Q000737:chemistry*; D019075:Electrophoresis, Capillary / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007287:Inorganic Chemicals / Q000302:isolation & purification*; D009930:Organic Chemicals / Q000302:isolation & purification*
D000838:Anions; D002412:Cations; D043844:Crown Ethers; D007287:Inorganic Chemicals; D009930:Organic Chemicals