摘要
研究了测定铁的一种新指示反应，在稀硫酸介质中，痕量铁（Ⅲ）对高碘酸钾与过氧化氢协同氧化变色酸２Ｒ的褪色反应具有强烈催化作用，其反应的动力学条件，表观活化能Ｅ′＝１８９．８１ｋＪ／ｍｏｌ，表观反应速率常数Ｋ＝５．６７×１０－４／ｓ，半衰期ｔ１／２＝２０．３７ｍｉｎ。反应温度为９０℃，试验表明ｌｇＡ０／Ａ与Ｆｅ（Ⅲ）的浓度在３０～１００ｎｇ／２５ｍＬ范围内符合Ｂｅｒ定律，建立了催化动力学光度法测定痕量铁的新方法。方法的检测限为１．２５×１０－９ｇ／Ｌ，加入回收率在９７．０％～１０２％，应用于测定西洋参口服液、美国花旗参茶和天然矿泉水中铁的含量结果满意。
In this paper,a new indicator reaction of potassium periodate and hydrogen peroxide with Chromotrope 2R in the presence of Fe(Ⅲ) as catalyst and the kinetic conditions have been studied.A new catalytic spectrophotometric method for determining trace Fe(Ⅲ) is established ,The limit of detection is 1.25×10 -9 g/L Fe,and the determination range is 30～100ng/25mL Fe.The method has been used for the analysis of A merican Ginseng,A merican Gingsen Tea and mineral water samples with satisfactory results.
出处
《分析试验室》
CAS
CSCD
1997年第5期46-48,共3页
Chinese Journal of Analysis Laboratory
关键词
催化动力学
光度法
高碘酸钾
过氧化氢
铁
Catalytic kinetic spectrophotometry
potassium periodate
hydrogen peroxide
chromotrope 2R
lron(Ⅲ)
