本文研究了铁（Ⅲ）－苯芴酮－Ｔｒｉｔｏｎｘ－１００体系测定锰镍铜中的铁。铁与苯药酮二元配合物的摩尔吸光系数可达６．４×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），加入表面活性剂Ｔｒｉｔｏｎｘ－１００后，铁与苯芴酮生成三元配合物，摩尔吸光系数值提高到２．４×１０￣５Ｌ·ｍｏｌ￣（－１）ｃｍ￣（－１）．铁（Ⅲ）含量在０～２５μｇ／５０ｍｌ范围内服从比耳定律，相对标准偏差２．３％，平均回收率９６．２％。反应选择性好，用于测定锰镍铜中的铁，结果令人满意。 In this paper, iron (Ⅲ) -benzene fluorenone-Tritonx-100 system for the determination of iron in manganese nickel copper was studied. The molar extinction coefficient of iron and benzophenone binary complexes reached 6.4 × 10 ~ 4L · mol -1 (-1) · cm -1. After the addition of surfactant Tritonx-100, the molar ratio of iron to benzofluorene Ketone to generate ternary complexes, the molar absorptivity value increased to 2.4 × 10 ~ 5L · mol ~ (-1) cm ~ (-1). Beer’s law was obeyed in the range of 0 ~ 25μg / 50ml with a relative standard deviation of 2.3% and an average recovery of 96.2%. The reaction selectivity is good, for the determination of iron in manganese nickel copper, the results are satisfactory.