改进Ferrozine法测定溶液中的二价铁、三价铁及总铁

铁元素是自然界中常见的微量元素之一,其在溶液中存在亚铁离子、三价铁离子两种价态。为了准确地定量测定亚铁、三价铁及总铁的含量,探索出一种改进的菲啰嗪(Ferrozine)法。二价铁和Ferrozine反应生成紫色络合物,其在562 nm处有最大吸收峰。利用该特点,可以直接测定二价铁含量,以盐酸羟胺为还原剂,将三价铁还原为二价铁后,即可测定总铁含量,进一步计算出三价铁含量。结果表明:该方法能准确测定游离二价铁及总铁,测定结果和ICP-AES法的结果吻合,同时三价铁计算结果和黄血盐测定三价铁的结果吻合;并且该方法可用于预测分散在水相的四氧化三铁纳米颗粒的铁含量,与ICPAES法相比,校正系数约为0.85。因此该方法适用性广,操作简单而经济,结果准确。

Determination of Fe2+, Fe3+ and Total Iron Ion with Improved Ferrozine UV-Spectrophotometry

Iron is one of the common elements in nature, and it exists two valence states in solution, namely ferric ions and ferric ions. To accurately determine the content of ferrous ions,ferric ions and total iron, this work has explored an improved Ferrozine method. Divalent iron can react with Ferrozine to form a violet complex, which has a maximum absorption peak at 562nm. Using this characteristic divalent iron content can be measured directly. Using hydroxylamine hydrochloride as the reducing agent,ferric iron is reduced to divalent ironit and total iron content can be determined, and further ferric iron content can be calculated. The results show this method can accurately determine free divalent iron and total iron, and the results are consistent to ICP-AES results. Ferric iron content calculated by Ferrozine method is consistent to the result detected by Ferrocyanide method. Moreover,this method can be used to determine iron content of iron oxide nanoparticles dispersed in the aqueous phase. Compared with ICP-AES method, the correction factor is about 85%. So this method is widly applicable,simple,economical and accurate.