A simulated moving bed separator and methods for isolating a desired component are provided. A method includes removing a raffinate from a raffinate bed of a simulated moving bed separator. The raffinate includes an undesired component, and the simulated moving bed separator includes a plurality of adsorbent beds circularly coupled together, a distributor, and a plurality of conduits coupling the distributor to the plurality of adsorbent beds. The adsorbent beds include the raffinate bed, a desorbent bed, and a zone 4 flush bed positioned between the raffinate bed and the desorbent bed. Desorbent is added to the desorbent bed through a desorbent conduit. The zone 4 flush conduit is flushed to the desorbent conduit, where the zone 4 flush conduit is coupled to the zone 4 flush bed.