A direct ion chromatographic method for determination of chlorite, chlorate and bromate in the presence of fluoride, chloride, nitrate, nitrite and bromide in treated drinking waters was described. Separation of target analytes was achieved using an AS19-HC analytical column (250 mm x 4 mm), AG 19-HC guard column (50 mm x 4 mm) and KOH 25 mmol/L as mobile phase. Inorganic analytes were eluted using a flow rate of 1 mL/min. Column temperature was set up and maintained at 300C. The analyte ions were quantified using a suppressed conductivity detector.