摘要:A two-step method was established for the separatory determination of nitrate-nitrogen and nitrite-nitrogen in waste or polluted water. In the first step, organic nitrogen and ammonia-nitrogen, which are liable to be decomposed in alkaline state, are removed by distillation, and the nitrate-nitrogen and nitrite-nitrogen are reduced by the Devarda alloy. In the second step, the same procedure is carried out after preliminary decomposition of the nitrite-nitrogen with sulfamic acid and the amount of nitrate-nitrogen is determined. This method was found to be practicable.