deionizer

deionizer de*i"on*iz`er n. (Chem.) an apparatus used to remove ions from a solution; a common variant contains a mixture of cation exchange resin in the acid form and anion exchange resin in the hydroxyl form inside a replaceable cartridge; ions in aqueous solution are exchanged for the elements of water by passing the solution through the mixed resin.

Note: In chemistry and biochemistry, experiments often require water free from contaminating ions, and ordinary distilled water may be further purified by passing through a deionizer in order to render the ion content sufficiently low so as not to interfere with the investigation. [PJC]