Ion chromatographic (IC) methods using sodium hydroxide and methanol gradients were used for the determination of small inorganic and organic anions as decomposition products of a tecnazene solution in water irradiated by UV light. After 60 min of UV irradiation, > 99% of the tecnazene was decomposed, and 11 organic and 3 inorganic anions were identified and quantified. A fourth inorganic anion, carbonate, was not quantified due to likely losses as carbon dioxide. The final content of chloride, total nitrogen, and total carbon released from the saturated tecnazene solution after 60 min bf UV irradiation were 108, 85, and 38%, respectively. These results suggest that other products rich in carbon and/or nitrogen (such as phenolic compounds and nitrobenzenes) were formed during the UV irradiation of the tecnazene solution. The results obtained indicate several decomposition pathways of tecnazene in water solutions, for example, ring opening reactions, dechlorination, and replacement of the ring nitro group. The determination of nonionic decomposition products from the latter two possibilities is the subject of further study.