This part of IS0 10304 specifies methods for the determination in aqueous solution of the dissolved anions - iodide, thiocyanate and thiosulfate (clause 4); - sulfite (clause 5); - chromate (clause 6).nitrate, nitrite, orthophosphate and sulfate in water, e.g. drinking water, ground water, surface water, waste water, leachates and marine water by liquid chromatography of ions. The lower limit of application is W 0,05 mg/l for bromide and for nitrite, and W 0,1 mg/l for chloride, fluoride, nitrate, orthophosphate, and sulfate. The lower limit of application depends on the matrix and the interferences encountered. The working range may be expanded to lower concentrations (e.g. W 0,01 mg/l) if an appropriate pre-treatment of the sample (e.g. conditions for trace analyses, pre-concentration technique) is applied, and/or if an ultraviolet (UV) detector (for bromide, nitrate and nitrite) is used.