Automated isotachophoretic analyte focusing for capillary zone electrophoresis in a single capillary using hydrodynamic back-pressure programming

On-line concentration of peptides and proteins with the hyphenation of polymer monolithic immobilized metal affinity chromatography and capillary electrophoresis

“…Up to now, two distinctly different methods for on-column sample enrichment have been developed, namely electrophoretic stacking [7][8][9][10][11][12][13] and chromatographic concentration [14,15]. The former one includes isotachophoresis [7], sample stacking [8,9], sweeping [10,11], and a dynamic pH junction [12,13], caused by the different electric fields applied on the sample zone and background electrolyte. In the latter one, in a capillary with stationary phase, the sample zone could be sharpened under the condition that the modified organic concentration in the mobile phase is higher than that in the sample buffer.…”

“…On-line concentration of sample is an alternative in CE to improve the concentration detection limits [7][8][9][10][11][12][13]. Up to now, two distinctly different methods for on-column sample enrichment have been developed, namely electrophoretic stacking [7][8][9][10][11][12][13] and chromatographic concentration [14,15].…”

“…In addition, a number of sensitive detectors, such as electrochemical detector, fluorescence detector, and mass spectrometry (MS), have also been successfully developed [4][5][6]. Nevertheless, they are sophisticated, expensive, selective, or difficult to automation compared with absorption detection.On-line concentration of sample is an alternative in CE to improve the concentration detection limits [7][8][9][10][11][12][13]. Up to now, two distinctly different methods for on-column sample enrichment have been developed, namely electrophoretic stacking [7][8][9][10][11][12][13] and chromatographic concentration [14,15].…”

Pressure‐assisted field‐amplified sample injection with reverse migrating micelles for analyzing trace steroids in MEKC

“…To improve ITP-CZE resolution and lower the detection limits in CZE, the counterflow pressure was utilized to balance the EOF and remove the terminating or leading electrolyte [32][33][34]. Similarly, pressure was also used in the CZE sample stacking to compensate the EOF [35,36].…”

Selective trace enrichment by immunoaffinity capillary electrochromatography on-line with capillary zone electrophoresis — laser-induced fluorescence

“…Several approaches are being explored to increase the concentration sensitivity of capillary separation techniques, including improved detection technologies [3,4], on-line coupling of isotachophoresis and capillary zone electrophoresis (CZE) [5,6], transient isotachophoresis in CZE [7,8], field amplification or ªstackingº [9±11] and online solid-phase extraction (SPE) [11±21]. Of these approaches, on-line SPE employing coated capillary sections, packed capillaries, or membranes, stands alone in its ability to accomplish trace enrichment of both charged and neutral analytes.…”