铁(Ⅲ)-9-(3,5-二溴)水杨基荧光酮-溴化十六烷基三甲基铵显色体系的分光光度法研究及应用

Study on the Colour Reaction of Iron(Ⅲ) with 3,5 Dibromosalicylfluorone and Cetyl Trimethyl Ammonium Bromide and Its Application

研究了铁（Ⅲ）－９－（３，５－二溴）水杨基荧光酮－ＣＴＭＡＢ三元络合物的显色反应条件，在ｐＨ６．０～７．２的ＫＨ２ＰＯ４－ＮａＯＨ缓冲体系中，铁（Ⅲ）与９－（３，５－二溴）水杨基荧光酮形成１∶４的络合物，其最大吸收波长λｍａｘ＝５９０ｎｍ，表观摩尔吸光系数为１．７２×１０５Ｌ·ｍｏｌ－１·ｃｍ－１，铁含量在０～６μｇ／２５ｍＬ范围内符合比耳定律．方法灵敏度高，选择性较好，络合物稳定，用于牛肝粉和茶叶中微量铁的测定。

A new colour reaction of iron with 3,5 dibromosalicylfluorone and Cetyltrimethylammonium bromide has been studied.The results show that in KH 2PO 4 NaOH buffer solution of pH from 6.0￣7.2,the soluble tetrabasic complex of iron(Ⅲ) with DBSF CTMAB is formed with the maximum absorption wavelength at 590 nm,the apparent molar absorption coefficient is 1.72×10 5 L·mol -1 ·cm -1 .The Beer′s law is obeyed in the concentration range of 0￣6 μg/25 ml for iron(Ⅲ).The molar ratio in the complex has been extimated to be Fe(Ⅲ)∶DBSF=1∶4.The colour reaction is simple,sensitive and selective.Satisfactory results have been obtained when it is used for the determination of ox liver powder sample and tea sample.