キャピラリー電気泳動法およびマイクロチップ電気泳動法のElectrokinetic supercharging：スタッキング機構と小イオンから生体高分子までの高感度分析への応用

抄録

This review summarizes the mechanism and applications of electrokinetic supercharging (EKS), an online preconcentration technique utilizing electrokinetic injection (EKI) coupled with transient isotachophoresis (tITP) in capillary electrophoresis and microchip electrophoresis. When the sample components (targets) are electrokinetically injected in the EKS procedure, the electrolyte filled in the separation capillary must (at least partly) contain a leading electrolyte (LE) that contains a co-ion with greater mobility than that of the targets to fulfill the condition of the ITP preconcentration. To complete preconcentration, further introduction of terminating electrolyte (TE) is useful. Obviously, the concentration factors of EKS strongly depend on essential EKI and tITP stages, thus two sections of this review are concentrated on the introduction of EKI and tITP. For EKI, several factors affecting the injected amount are discussed and concluded here. For tITP, different introduction modes for the sample, the optimization of the LE and TE to enhance preconcentration are also mentioned. So far, several high-sensitivity applications to metal ions, drugs, peptides, DNA fragments, and SDS-proteins have illustrated that EKS was an effective and promising stacking technique.