论文部分内容阅读
在pH约为2.2,用抗坏血酸把铁(Ⅲ)还原为铁(Ⅱ)。当PH=5-6,在非离子表面活性剂吐温-80存在下,铁(Ⅱ)与5-Br-PADAP形成稳定的有色络合物,其最大吸收位于560纳米,表观摩尔吸光系数为7.3×10~4在0-10微克铁(Ⅱ)/25毫升服从比耳定律。加入一定量EDTA、酒石酸钾钠和硫脲,可消除某些离子的干扰。锌、锑中痕量铁,不预先分离,直接在水相中用本法测定。可获得较满意的结果,操作简便快速。
Iron (III) is reduced to iron (II) with ascorbic acid at a pH of about 2.2. At pH = 5-6, iron (Ⅱ) forms a stable colored complex with 5-Br-PADAP in the presence of non-ionic surfactant Tween-80 with a maximum absorption at 560 nm and an apparent molar absorptivity Beer’s law is obeyed at 7.3 × 10 -4 for 0-10 μg iron (Ⅱ) / 25 ml. Add a certain amount of EDTA, potassium sodium tartrate and thiourea, to eliminate some of the interference of ions. Zinc, antimony trace of iron, without prior separation, directly in the water phase using this method. Get more satisfactory results, easy to operate fast.