铁(Ⅲ)-对氨基苯基荧光酮-变色酸-OP体系分光光度法测定铁

Spectrophotometric determination of iron with iron(Ⅲ)-p-aminophenylfluorone-chromotropic acid-OP color system

在碱性介质中,铁（Ⅲ）与对氨基苯基荧光酮和变色酸及乳化剂OP发生显色反应,据此建立了分光光度法测定铁的方法。研究发现：铁（Ⅲ）与对氨基苯基荧光酮及变色酸及OP形成了绿色的四元混配胶束络合物,该络合物的最大吸收波长为620 nm,且络合物中铁（Ⅲ）与对氨基苯基荧光酮及变色酸的组成比nFe（Ⅲ）∶nAPF∶nCA为1∶2∶1。在10 mL溶液中铁质量在1~10μg范围内服从比尔定律,相关系数为0.999 5。方法用于铝合金样品中微量铁的测定,结果同经典的邻二氮杂菲法所得结果相吻合。

A spectrophotometric determination method of iron was established based on the color reaction between Fe（Ⅲ） and p-aminophenylfluorone（APF）,chromotropic acid and emulsifier OP in alkaline medium.It was found that Fe（Ⅲ） could form a green quaternary blending micellar complex with APF,chromotropic acid（CA） and OP.The maximum absorption wavelength of this complex was at 620 nm.The composition ratio was nFe（Ⅲ）∶nAPF∶nCA=1∶2∶1.Beer＇s law was obeyed for iron in 1-10 μg/10 mL with the correlation coefficient of 0.999 5.The proposed method was applied to the determination of trace iron in aluminium alloy samples,and the results were consistent with those obtained by classical o-phenanthroline analysis method.