Transient ITP in nonaqueous CE by introducing ions with a long hydrophobic chain as terminating ions

Abstract

Transient isotachophoresis (tITP) is an efficient sample-preconcentration procedure for improving detection limits. An isotachophoretic state exists at the beginning of the procedure as a result of the introduction of both leading and terminating ions into the system. tITP has usually been applied in aqueous media, and hydrophilic compounds have been used as leading and terminating ions; this study, however, focused on nonaqueous capillary electrophoresis (NACE) and use of ions with long hydrophobic chains as terminating ions for tITP. Because the long alkyl or aryl structures of these compounds can lead to low mobility in capillary electrophoresis, use of such ions as terminating ions in tITP can broaden the applicable range of the tITP procedure and achieve the ITP effect under more flexible running conditions. © 2006 Friedr. Vieweg & Sohn/GWV Fachverlage GmbH.