The leading electrolyte establishes the faster-mobility region, while the trailing electrolyte defines the slower-mobility region. Their arrangement creates the conditions needed for the target ion to remain between them during electric-field-driven migration. This organized electrolyte structure supports localized focusing and helps distinguish the target from ions moving with different electrophoretic mobilities.
Electrophoretic mobility controls how quickly ions migrate under the applied electric field, whereas conductivity contributes to the field and transport conditions across the electrolyte regions. The interaction of these properties positions the target ion between the leading and trailing electrolytes. Their combined effect produces a sharp concentration peak instead of a diffuse distribution.
A narrow peak places more of the target ion in a localized region, increasing its concentration relative to a broadly distributed band. This concentration behavior supports analyte preconcentration and can improve the basis for sensitive detection. The focused zone also provides a distinct feature for analyzing ion separation in electrophoretic and microfluidic systems.
The applied electric field drives ions through the leading and trailing electrolyte regions and makes differences in electrophoretic mobility operationally important. As ions respond to this field, the target becomes focused at the boundary between regions with different transport conditions. This makes Peak Mode ITP a useful framework for examining field-driven focusing and coupled electrokinetic processes.
A conceptual workflow begins by establishing a leading electrolyte and a trailing electrolyte, introducing the target ion between their mobility conditions, and applying an electric field. Ion migration then produces a localized concentration peak between the two electrolyte regions. The resulting focused zone can be used for separation, preconcentration, or subsequent detection.
Researchers can use this mode when they need to concentrate a target ion before analysis, separate ions according to electrophoretic mobility, or create a localized signal for detection. Its relevance extends across electrophoretic and microfluidic systems because it connects ion transport with field-driven focusing. In physics, it also supports study of coupled electrokinetic behavior.