The disinfection policy of the National Water Carrier (NWC) of Israel has recently been changed from chlorine to chlorine dioxide. One of the objectives was therefore to determine precisely all the inorganic products of such disinfection. It was found that none of the known analytical methods could satisfactorily solve this problem, determining all the inorganic species which were formed. The determination of all the oxidants became possible, however, when a few analytical methods or their combinations were applied simultaneously. The validity of the methods described in this study was further confirmed by the good balance that was obtained between the ClO2applied and the total oxidants determined after various time intervals.