鉄(II)-EDTA水溶液における二酸化窒素吸収反応のポーラログラフィーによる検討

概要

論文の詳細を見る
The behavior of nitrogen dioxide were studied in ethylenediaminetetraacetato iron (II) {Fe (II)-edta} aqueous solutions at pH 4.2 and pH 8.5. Nitrogen gas including 3.0% of NO_2 and the 0.019 mol dm^<-3> Fe(II)-edta solution of pH 4.2 or pH 8.5 were mixed in a gas cylinder, and the formed nitrosyl complex, Fe(II)NO-edta, was determined by polarography. The conversion rates of Fe(II)NO-edta from NO_2 were 0.7 at pH 4.2, and 0.12 at pH 8.5. In the acidic solution, about 30% of absorbed NO_2 is changed into some species (probably nitrate ion) which does not form the nitrosyl complex. On the other hand, in the alkaline solution the main product is estimated nitrite ion which does not react with the Fe(II)-edta at this pH value. The conversion rates of Fe(II)NO-edta from NO_2 was raised to 0.82 when potassium iodide (0.96 mol dm^<-3>) was added to the acidic solution. For the analysis of nitrogen oxides, the concentration of NO and NO_2 can be given respectively by solving simultaneous equations shown as follows. C_a= C_<NO>+0.82 C_<NO_2> C_b=C_<NO>+0.12 C_<NO_2> where C_a and C_b are concentrations of Fe(II)NO-edta determined in the acidic solution containing potassium iodide and the alkaline solution respectively, and C_<NO> and C_<NO_2> are concentrations of NO and NO_2 to be determined.
社団法人日本分析化学会の論文
1979-02-05