Figure 6.

Parabolic shape of an analyte in a laminar flow inside a tube. The flow travels at an average linear velocity of v, with maximum velocity of 2v in the center. There is a plane that travels at v, and this plane is taken as a representative plane of analytes moving as a parabola (denoted as a dashed circle). The radius of the dashed circle is a/ $\sqrt{2}$ where the reagent, R, occupies half of this circle, and the analyte, A, occupies the other half. The average diffusional relaxation time in the disk is calculated using eq 13, where r is the radial distance from the center of the tube.