An apparatus for suppressing an eluent of an aqueous sample stream including analyte ions of one charge, positive or negative, comprises a primary channel member, a first block, a first regenerant flow channel, a first charged barrier, a second block, a second regenerant flow channel, a second charged barrier, a first stationary flow-through ion exchange material, and optionally a first electrode and a second electrode. The first stationary flow-through ion exchange material comprises a polyolefin substrate having a functional polymer layer disposed thereon. The polyolefin substrate has a pore structure with a pore size ranging from about 5 microns to about 250 microns. The functional polymer layer has a thickness ranging from about 1 micron to about 20 microns, and a layer pore structure having a pore size ranging from about 1 nm to about 100 nm. The functional polymer layer comprises an ion exchange layer.