Order of magnitude estimates for Péclet numbers are consistent with the theory that peak area reduction with increasing flow rate occurs due to entrapment of the Ad5 particles by the flowing liquid at pore constrictions in the monoliths, 4 CIM disks (- · - ·), ProSwift (- - -), Uno Q (·········), and in the perfusive resin, PL-SAX (—). The horizontal gray line at Pe = 1 indicates where diffusion and convection are approximately in balance.