This document specifies a method for the determination of dissolved perchlorate in water (e.g. drinking water@ mineral water@ raw water@ surface water@ partially treated water or swimming pool water@ waste water from drinking/swimming pool water treatment plants). Appropriate pre-treatment of the sample (e.g. matrix elimination) allows a direct determination of perchlorate ??1 ??/l. The working range is restricted by the ion-exchange capacity of the separator column. Dilution of the sample to the working range can be necessary