(IC) - An ion-exchange technique in which low concentrations of anions or cations are determined using low-capacity ion exchangers with weak buffers. Conductivity detectors are often used. Ion chromatography is practiced in two forms. In suppressed IC, a second column is used to remove the buffer ions so that sample ions can be more easily detected; membrane separator is sometimes used. In nonsuppressed IC, weakly conducting buffers at low concentration are carefully selected, and the entire effluent is passed through the detector; ions are detected above the background signal.