研究了极谱法测定饲料添加剂中游离亚铁离子含量的方法。在柠檬酸铵溶液（ｐＨ９１）中，Ｆｅ２＋与４－（２－吡啶偶氮）间苯二酚（ＰＡＲ）形成的络合物产生一灵敏还原吸附波，可用于单扫描示波极谱法测定微量铁（Ⅱ）。铁（Ⅱ）浓度在１０×１０－８～１０×１０－６ｍｏｌ·Ｌ－１浓度范围内与导数波高呈线性关系，检测下限为７５×１０－９ｍｏｌ·Ｌ－１。该法应用于测定饲料添加剂氨基酸螯合亚铁中的游离亚铁离子，并用多种电化学手段对络合物的电化学性质进行了研究 The method of polarographic determination of free ferrous ion content in feed additives was studied. In the ammonium citrate solution (pH9.1), the complexes formed by Fe2 + and 4- (2-pyridylazo) resorcinol (PAR) produce a sensitive reduction adsorptive wave that can be used for single-sweep oscillopolarographic Determination of trace iron (Ⅱ). The concentration of iron (Ⅱ) showed a linear relationship with the derivative wave height in the range of 1 × 10-8 ~ 1.0 × 10-6 mol·L-1 with the detection limit of 75 × 10-9 mol·L-1. The method was applied to the determination of free ferrous ions in the amino acid chelated ferrous iron as feed additive, and the electrochemical properties of the complex were studied by various electrochemical methods