关键词: 邻菲罗啉, 分光光度法, 无水乙醇, 络合铁

Abstract: An improved phenanthroline spectrophotometric method for the determination of ferrous content in chelated iron was propsed，aimed at unclear color reaction of standard HJ/T 345—2007. By improving reagent addition sequence and replacing part of water with 20 mL of ethanol，when pH of the solution was between 3 to 9，o-phenanthroline with chelated ferrous could form a stable orange red complex. The maximum absorption wavelength of the complex was 510 nm. This method can solve the problem of the unobvious color in the detection of the chelated ferrous by the standard HJ/T 345—2007 and the recovery rate of the sample was 98.0% to 102.0%.

Key words: phenanthroline, spectrophotometric method, ethanol, chelated iron