桑色素（Morin）多用于离子的荧光试剂，本文用Morin作为显色剂，在非离子表面活性剂Tween80存在下，测定水中微量Fe（Ⅲ），回收率为95．8％～102．5％，相对标准偏差小于5％，结果满意。1实验部分1．1主要试剂与仪器721型分光光度计，PHS—1型酸度计。铁标准溶液：1．0mg／ml In this paper, Morin was used as a chromogenic reagent to detect trace Fe (Ⅲ) in water, and the recoveries were 95.8% -102.5% in the presence of non-ionic surfactant Tween80. , Relative standard deviation less than 5%, the results are satisfactory. 1 Experimental 1.1 The main reagents and instruments 721 spectrophotometer PHS-1-type pH meter. Iron standard solution: 1.0 mg / ml