邻菲啰啉分光光度法测定络合铁脱硫液中铁的含量

Determination of iron content in chelated iron desulphurization solution by phenanthroline spectrophotometry

以邻菲啰啉为显色剂,采用紫外-可见分光光度计测定Fe-NTA体系中全铁、Fe^(2+)、Fe^(3+)的浓度。分别考察了FeNTA脱硫液中的络合比例、温度、电解质浓度等因素对溶液吸光度的影响。结果表明,当n(NTA)∶n(Fe^(3+))=1.5∶1,温度为298 K时,脱硫液吸光度值有最大响应值,脱硫液中电解质Na Cl的浓度为0~0.2 mol/L对铁离子的吸光度没有显著影响。在上述条件下,波长为512 nm处得到Fe-NTA脱硫液的标准曲线方程为:A=0.002 39+0.011 6c,R2=0.999 5。铁离子检测适用范围为20~200μmol/L,根据标准曲线方程可计算Fe-NTA脱硫体系中全铁、Fe^(2+)、Fe^(3+)的浓度。

The concentration of total iron,chelated ferrous ion and chelated ferric iron of Fe-NTA system are determined by UV-Vis spectrophotometer with the chromogenic agent phenanthroline. The effect of the complex proportion of Fe-NTA,temperature and electrolyte concentration are investigated. The results show that,when n（ NTA） ∶ n（ Fe3 ＋） =1. 5∶ 1 and T = 298 K,the absorbance of the desulfurization solution has the maximum response value. The concentration of the electrolyte Na Cl has no significant effect on the absorbance. Under the above conditions,standard curve equation of Fe-NTA obtained at 512 nm is shown as follows： A = 0. 002 39 ＋ 0. 0116 C,R2= 0. 999 5. The detection range of iron ion is 20- 200 μmol / L. According to the standard curve equation,the concentration of total iron,chelated ferrous ion and chelated ferric iron can be calculated.