Experimental investigation of the streaming current generated by the liquid mobile phase inside the chromatographic separation column packed with solid particles revealed that the measured streaming current changes only when the zones of analytes are leaving the column. This characteristic can be understood from basic electrodynamic properties of the particle-medium interface. Local double-layer compositions inside and outside the analyte zone, the corresponding electrokinetic behavior, and the dynamics of the double-layer adjustment to variations in the local composition of the flowing liquid are considered.