中文摘要：

近年来，由于含铁水处理剂的广泛应用，水体中铁含量逐渐增高。含铁量高的水在管道内易生长铁细菌，增加水的浑浊度，使水产生特殊的色、嗅、味，易污染衣物、器皿，影响某些工业产品的质量。因此，研究准确快速测定水中铁的分析方法具有重要意义。铁（Ⅲ）的分析方法有AAS、ICP—MS、ICP—AES、HPLC等。这些方法灵敏度高，选择性好，但是仪器昂贵使得方法的应用范围受到很大的限制。铁（Ⅲ）催化的动力学光度法由于仪器价廉、选择性好而被广泛应用。实验中发现，在pH3．7的HAc—NaAc缓冲溶液中，痕量碘化钾存在下，铁（Ⅲ）对溴酸钾氧化4，4’-四甲替二氨基二苯甲烷显色反应有显著的催化作用，当反应进行约50s时在波长602nm处具有最大吸收。

英文摘要：

Trace amounts of iron were determined by flow injection catalytic kinetic speetrophotometry, based on the catalytic effects of iron on the redox reaction between potassium bromate and 4,4＇ - tetramethyldiaminodipbenylmethane in the presence of potassium iodide in HAe - NaAe buffer solution. The measuremeats were conducted at 602nm of an unstable blue product of the reaction. Flow injection technique was utilized to precisely control the timing of merging and reaction of the reagents and samples. A stopped -flow approach was used to improve the sensitivity oftbe system. A detection limit of 2.6 × 10^-9g/mL was achieved at a sampling frequency of 45/h. Calibration graphs were linear for ranges of 0 ~ 0.4mg/L for Fe（Ⅲ）. The proposed method was validated by the analysis of a national reference material and applied to the analyses of several water samples, with recoveries of 95.9%to 97.3%.