流动注射-分光光度法测定水中铁的形态

FLOW INJECTION-SPECTROPHOTOMETRIC ANALYSIS OF IRON SPECIATION IN NATURAL WATER

用流动注射-分光光度法研究了水中可溶态和悬浮态中铁的形态分析.将Fe^(2+)与邻菲罗啉的显色反应引入流动系统,用固体抗坏血酸方便地将Fe^(2+)预先还原.O—2.5ppm的Fe^(2+)符合比尔定律,测定限为O.02ppm,低于已报导的文献.2ppm Fe^(2+)经五次测定的相对标准偏差为0.5％,进样频率250次/h.进行了雨水、湖水、自来水中铁的形态分析,取得了满意的效果.

Analysis of iron speciation in water was studied by flow injection-spec-trophotometric method. The colour-development reaction of Fe2+ and 1,10-phen-anthroline was used in the flowing system. The optimum condition was chosen and the Fa3+ was reduced by solid ascorbic acid for the determination of total iron before the samples were injected. Within 0-2.5ppm range of Fe2 + Beer's law is held and a detection limit of 0.02ppm is lower than those reported in the literature. The relative error is ±0.05 ppm , when the concentration of Fe2+ and Fe3+ is 1 ppm in the synthetic sample. The relative standard deviation of 2 ppm Fe2+ is 0.5% (n=5). The above method provided a technique with the capacity of routine analysis for 250 injections per hour. We have analyzed Fe2+ and Fe3+ in aqueous phase and in suspension matter of rain--water and tapwater and lake-water were analysed with satisfactory results.