Patent ID: 7399415

Claim:
In a method for analysis of sample, ionic species of one charge, positive or negative, ma liquid sample, the steps of (a) parking liquid sample including said ionic species and at least one matrix compound including matrix ions of opposite charge to said ionic species, said parking being performed by flowing said liquid sample into a sample compartment and stopping said flow, said sample compartment having a first wall comprising at least one ion-exchange membrane capable of transporting ions of one charge, positive or negative, and having exchangeable ions of the same charge as said matrix ions, said parked liquid sample being on one side of said one membrane, (b) flowing a regenerant liquid stream through a regenerant flow compartment on the other side of said one membrane from said parked liquid sample, (c) transporting at least some of said matrix ions in said parked liquid sample across said one membrane into said regenerant flow compartment to be carried away in said regenerant solution, (d) after step (c), removing said liquid sample from said sample compartment, and (e) separating said ionic species in said removed liquid sample.