An ion-exchange technique in which low concentrations of organic and inorganic anions or cations are determined using ion exchangers of low ion-exchange capacity with dilute buffers. Conductivity detectors often are used. IC is practiced in two forms: In suppressed IC, a second column or a membrane separator is used to remove the buffer counter ion from the analyte and simultaneously replace it with a hydrogen or hydroxide ion that concomitantly converts the buffer to an uncharged species thereby suppressing background and enhancing sensitivity. In nonsuppressed IC, low-concentration, weakly conducting buffers are carefully selected, the entire effluent is passed through the detector, and ions are detected above the background signal.