Application of ion-exchange resins to the fractionation of metals in water

This article surveys the analytical strategies developed for the fractionation of heavy metals in natural occurring waters using commercial synthetic ion-exchange resins in various column or batch protocols. Different approaches to integrating physical fractionation by filtration or ultrafiltration with chemical sensing of specific groups of metals are presented. Ion-exchange-based procedures that enable the study of the dissociation kinetics of metal species are also reported. The usefulness, simplicity and convenience of ion-exchange-resin-based methods in fractionation analysis are discussed. In addition, attention is drawn to some selected aspects of sample storage and pre-treatment along with a warning about the quality control of measurements.