溴代二甲氨基苯基荧光酮的合成及其与铁显色反应的研究

Studies on the Synthesis of Bromodimethylaminoaniline- fluorone and Its Colour Reaction with Iron

报道了溴代二甲氨基苯基荧光酮(简称BDMAF)的合成及鉴定;研究了在第二配体及表面活性剂存在下,BDMAF与微量铁的显色反应。在乙酰丙酮及CTMAB存在下,铁与显色剂形成蓝色配合物,其表观摩尔吸光系数达1.61x10^5L/mol·cm。以EGTA作为掩蔽剂可不经分离直接测定某些纯金属及合金中的微量铁。

A highly sensitive colour reagent bromodimethylaminoaniline-fluorone (BDMAF) was synthesized and identified. The colour reaction of BDMAF with iron in the presence of auxiliary complexing ligands and surfactants was studied systematically. The blue quaternary complex of Fe-acetylacetone-BDMAF-CTMAB exhibits absorption maximum at 608 nm with an apparent molar absorptivity of 1 .6 × 105 L.mol-1 .cm-1 in the medium of NH3-NH4C1 buffer of pH 9.5-10.5. Its apparent stability constant is 6.8×1012. Beer's law is obeyed for iron of 0-5.5 mg/25 L. The composition of this complex was found to be Fe( Ⅲ):BDMAF = 1:2. The method has a high selectivity in the presence of 'EGTA, it has been applied to the determination of trace amounts of Fe3+ in zinc alloys without separation. The variation coefficients are 3.2%-3.9% for the four standard samples of zinc alloys measured (7 times).