Biomedical Engineering – From Theory to Applications

Column Coupling Electrophoresis in Biomedical Analysis
Fig. 5. Schematic representation of the ITP–CEC procedure (with a supporting non selective
flow). The sample loading, ITP focusing step, sample zone transfer and CEC separation are
shown in step 1, 2, 3 and 4, respectively. The set-up contains a (D) UV–VIS absorbance or
MS detection, (T) terminator buffer and (L) leading buffer. Untreated fused-silica capillaries
of 220 m I.D. (1 and 2) and 75 m (3) are used. Reprinted from ref. (Mazereeuw et al.,
2000)., with permission.
3.1.1.4 CZE-CZE
CE separation system with tandem-coupled columns, i.e. CZE-CZE makes possible, within
certain limits, splitting a CZE run into a sequence of the separation and detection stages (for
the general instrumental scheme valid also for CZE-CZE, see Fig. 1). Therefore, the carrier
electrolyte employed in the first (separation) stage of the run could be optimized with
respect to the resolution of an analyte from complex (biological) matrix. In this way, a very
significant ‘‘in-column’’ clean-up of the analytes from complex ionic matrices can be reached
in the separation stage of the tandem by combining appropriate acid-basic (pH) and
complexing (selectors) conditions. Due to this, the detection (e.g. spectral) data could be
acquired in the detection stage of the tandem with almost no disturbances by matrix comigrants
(Danková et al., 2003).
The carrier electrolyte employed in the second (detection) stage could be chosen to reach
favourable conditions in the acquisition of detection (e.g. spectral) data while maintaining
the resolution of the analyte from matrix constituents as achieved in the separation stage
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