Fe(Ⅲ)-5-Br-PADAP络合物光化学还原反应的抑制及其分析应用  

Inhibition of photochemical reduction of Fe(Ⅲ)-2-(5-bromo-2-pyridylazo)-5-diethylaminophenol complex and its analysis application

作　　者：吴小华[1] 方克鸣[1] 缪吉根[1] 陈建荣[1] 

机构地区：[1]浙江师范大学化学与生命科学学院,金华321004

出　　处：《分析试验室》2007年第5期46-49,共4页Chinese Journal of Analysis Laboratory

基　　金：浙江省分析测试基金(98061)项目资助

摘　　要：在乙酸、乙二酸、丙二酸、HF、H3PO4等缓冲溶液中,Fe(Ⅲ)-5-Br-PADAP络合物的光化学还原反应表明:乙酸能促进Fe(Ⅲ)-5-Br-PADAP络合物的光化学还原反应;HF、H3PO4初始能抑制该光化学还原反应,但随光照时间增加,该光化学还原反应仍能发生;乙二酸、丙二酸能抑制该光化学还原反应,其中丙二酸的抑制效果较好。确定了在丙二酸-丙二酸钠缓冲溶液中,Fe(Ⅲ)存在下,用5-Br-PADAP分光光度法测定Fe(Ⅱ)的实验条件,用于合成试样及铁矿中铁的价态分析。The photochemical reduction of Fe （ Ⅲ ）-5-Br-PADAP complex was studied in acetic acid, oxalic acid, malonic acid, hydrofluoric acid and phosphoric acid buffer solutions. The results show that acetic acid could promote the photoreduction of Fe（ Ⅲ ）-5-Br-PADAP; hydrofluoric acid and phosphoric acid initially inhibited the photoredution, but with the increase of illuminating time, the photoreduction continued to occur; oxalic acid and malonic acid inhibited the photoreduction of Fe（ Ⅲ ）-5-Br-PADAP complex remarkably, wherein malonic acid showed the strongest inhibitory effect. Accordingly, the optimized experimental conditions were established for spectrophotometric deterrnination of Fe（ Ⅱ ） with 5-Br-PADAP in malonic acid-sodium malonate buffer solution in the presence of Fe（ Ⅲ ）, and satisfactory results were obtained from the analysis of ferrous valences in both synthetic samples and iron ore using the method reported here.

关 键 词：铁 2-(5-溴-2-吡啶偶氮)-5-二乙氨基苯酚 抑制光化学还原 分光光度法 

分 类 号：O614.811[理学—无机化学]