This International Standard specifies a continuous flow analysis (CFA) method for the determination of sulfate in various types of water (such as ground water, drinking water and waste water). The method is applicable to samples with a sulfate (SO4) mass concentration from 30 mg/l to 300 mg/l. Other concentration ranges are applicable, provided they cover exactly one decade of concentration units (e.g. 100 mg/l to 1 000 mg/l).