【摘要】 研究了在聚乙烯醇存在下,Fe3+与硫氰酸钾和茜素红的显色反应,提出了分光光度法测定铁的新方法。在聚乙烯醇保护下,铁与硫氰酸钾和茜素红反应生成红色三元络合物,该络合物的组成比为n(Fe)∶n(硫氰酸钾)∶n(茜素红)=1∶4∶1,最大吸收波长位于430 nm,铁的质量浓度在0~200μg/L范围符合比尔定律,表观摩尔吸光系数ε=2.92×105L.mol-1.cm-1。方法用于管网水和深井水的测定,相对标准偏差分别为3.1%和2.8%(n=5),加标回收率为97%~98%。更多还原

【Abstract】 The chromogenic reaction of Fe(Ⅲ)with potassium thiocyanate and alizarin in the presence of polyvinyl alcohol had been researched,and a new spectrophotometric method to determine iron had been introduced.Under the protection of polyvinyl alcohol,Fe(Ⅲ) reacts with potassium thiocyanate and alizarin red to form a red ternary complex,whose component ratio is n(Fe)∶n(potassium thiocyanate)∶n(alizarin red)=1∶4∶1 and the maximum absorption wavelength is 430 nm.Beer’s law is obeyed in the mass concentration range of 0-200 μg/L for Fe(Ⅲ),with the apparent molar absorptivity of 2.92×105 L·mol-1·cm-1.Fe(Ⅲ) in tap water and deep well water had been determined by using this method,with the relative standard deviation of 3.1% and 2.8%(n=5),and the added standard recovery of 97%-98%.更多还原