高碘酸钾氧化丽春红-2R催化动力学单扫描示波极谱法测定痕量Fe(Ⅲ)的研究  

Study on single sweep polarographic determination of trace Iron(Ⅲ) through its catalytic reactionon the oxidation of ponceau2R by potassium periodate

作　　者：李巧云[1] 闫月荣[2] 

机构地区：[1]常熟理工学院化学系,常熟215500 [2]河南焦作师范高等专科学校,焦作454100

出　　处：《分析试验室》2005年第8期51-54,共4页Chinese Journal of Analysis Laboratory

摘　　要：研究了在H2SO4介质中,痕量Fe(Ⅲ)催化KIO4氧化丽春红-2R的褪色反应,提出了催化动力学单扫描示波极谱法测定痕量铁的新方法.在1.6×10-3mol/L H2SO4介质中,丽春红-2R在汞电极上产生1个灵敏的还原峰,峰电位为-0.224 V(vs.SCE)左右;在KIO4存在下,丽春红-2R峰电流的降低与加入Fe(Ⅲ)质量浓度在0～0.04μg/mL范围内呈良好的线性关系,检出限达到6.28×10-9μg/mL.同时探讨了反应条件、极谱波的性质和电极反应机理,已用于中草药中铁的测定,回收率为98.9%～102.2%.A new kinetic method for the determination of trace Iron（ Ⅲ ） was established based on the catalytic ef- fect of Iron（ Ⅲ ） on discoloration of ponceau 2R oxidized by KIO4 in a medium of sulfuric acid. In the preseuce of 1.6 ×10^-3 mol/L H2SO4 solution. Ponceau 2R has a well-diefined polarographic reduction peak at -0.224 V. The reduction peak current decreased in the presence of KI04 and iron（ Ⅲ）. The peak current at the -0. 224 V was proportional to the concentration of Iron（ Ⅲ） in the rang of 0 - 0.04 μg/mL, and the detection limit was to 1.12 × 10^-9 g/mL. The properties of the polarographic wave and the mechanism of the electrode reaction were studied. The method was applied to the determination of Iron （ Ⅲ ） in Chinese herbal medicine with recoveries in the rang of 98.9% - 102.2%. This method is simple and rapid with high selectivity.

关 键 词：丽春红-2R 催化动力学 单扫描示波极谱法 

分 类 号：O657.1[理学—分析化学]