Fe^(3+)、Fe^(2+)的连续测定

Continuous determination of iron(Ⅲ) and iron(Ⅱ)

在强酸性溶液中，Ｆｅ３＋ 和Ｆｅ２＋ 共存，以磺基水杨酸作指示剂，用ＥＤＴＡ 滴定Ｆｅ３＋ ，终点由紫红色突变至亮黄色。然后加入Ｈ２Ｏ２ 氧化Ｆｅ２＋ ，继续用ＥＤＴＡ 滴定至终点由黄绿色至亮黄色，实现了Ｆｅ３＋ 、Ｆｅ２＋ 的连续测定。

In the strong acid solution,Fe 2+ co-existing with Fe 3+ ,sulfosalicylic acid as indictor,the Fe 3+ was titrated by sodium ethylenediamine tetracetate, meanwhile the colour of ending point in titration varies from purgle red to bright yellow.After adding hydrogen peroxide,Fe 2+ was oxidized to Fe 3+ and titrated by sodium ethylenediamine tetracetate continuously.