Medical Term:

cation exchanger

Pronunciation: kat′ī-on eks-chānj′ĕr

Definition: An insoluble solid (usually a polystyrene or a polysaccharide) that has negatively charged radicals attached to it (–COO−, –SO3−), which can attract and hold cations that pass by in a moving solution if these are more attracted to the acid groups than the counter ion present.