摘要：

在n-C₇H₁₆/n-C₄H₉OH/CPC/H₂O微乳液介质中,以邻菲啰啉(Phen)为活化剂时,Fe(Ⅲ)对H₂O₂氧化亚甲基蓝褪色反应具有催化作用,据此建立了动力学光度法测定Fe(Ⅲ)的新方法。该方法的最佳实验条件为0.6mL亚甲基蓝溶液(1.0×10-3mol/L),0.2mLH₂O₂(20%),1.4mLPhen(1.0×10-3mol/L),1.8mL微乳液,2.0mLHAc-NaAc缓冲溶液(pH=4)。对Fe(Ⅲ)测定的线性范围为1.0～40μg/L,检出限为8.4×10-7g/L。100℃时的反应速率常数为0.0280min-1,表观活化能为36.22kJ/mol,可用于环境水样中Fe(Ⅲ)的测定。

关键词: 微乳液, 邻菲啰啉, 铁(Ⅲ), 动力学光度法

Abstract:

A new kinetic spectrophotometric method for the determination of trace Fe(Ⅲ) has been studied. It is based on the catalytic effect of Fe(Ⅲ) on the decolouring reaction of MB by H₂O₂ in the presence of microemulsion n-C₇H₁₆ /n-C₄H₉OH/CPC/H₂O and 1, 10-phenanth roline(Phen) as activator. The optimum conditions are 0.6 mL 1.0 ×10-3 mol /L MB, 0.2 mL 20% H₂O₂, 1.4 mL 1.0 ×10-3 mol /L Phen, 1.8 mL microemulsion, 2.0 mL HAc-NaAc(pH=4). The linear calibration curve from 1.0 to 40 μg/L of Fe(Ⅲ) and the detection limit of 8.4 ×10-7g/L are reported. The speed constant of the reaction at 100 ℃ is 0.028 0 min-1 and the apparent activation energy is 36.22 kJ /mol. The method has been used to determine Fe(Ⅲ) in water samples with satisfactory results.

Key words: microemulsion, 1, 10-phenanthroline, iron(Ⅲ), kinetic spectrophotometry

中图分类号: 

• X832