title: Operational modes for transient isotachophoretic preconcentration-capillary zone electrophoresis and detectable concentration of rare earth ions.
abstract: Operational modes for transient isotachophoretic preconcentration capillary zone electrophoresis (tr-ITP-CZE) were studied by using 5 microM and 0.5 microM rare earth mixtures as analytes in comparison with field-enhanced sample stacking. After examination of several operational modes for tr-ITP, it was found that tr-ITP effectively occured even if both the leading electrolyte and the terminating electrolyte were injected after the sample plug. This was explained as the result of a field-enhanced stacking for both sample components and the leading and terminating ions. The observed theoretical plate numbers were 4-20 times higher than those obtained by normal stacking; and the estimated low limit of detectable concentration of rare-earth elements (REE) was ca. 0.1 microM which was 2.5 times lower compared to normal stacking. For the 0.5 microM sample, a concentration factor of 20 000 could be achieved after only tr-ITP.
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-hiroshima, Japan. hiro77@hiroshima-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Hirokawa
authors.forename: H
authors.initials: H
authors.lastname: Okamoto
authors.forename: N
authors.initials: N
authors.lastname: Ikuta
mesh_terms: D004573:Electrolytes; D019075:Electrophoresis, Capillary / Q000379:methods*; D008674:Metals, Rare Earth / Q000032:analysis*
chemical_list: D004573:Electrolytes; D008674:Metals, Rare Earth