用胶束光度法测定非晶态FeNiCr合金中的铁和镍

Determination of Fe and Ni in Amorphous FeNiCr Alloy by Micellar Spectrophotometry

在pH值为1.0的HClKCl、pH值为8.0的HCl三羟甲基氨基甲烷(tris)缓冲溶液和Tween80胶束介质中,分别研究了1亚硝基2萘酚(NN)与Fe(Ⅲ)、Ni(Ⅱ)的显色反应。建立了胶束紫外可见分光光度法测定微量Fe(Ⅲ)、Ni(Ⅱ)的新方法。结果表明,Fe(Ⅲ)NN(pH值为1.0)、Ni(Ⅱ)NN(pH值为8.0)配合物的最大吸收波长分别为445nm和455nm;摩尔吸光系数分别为1.68×104L/(mol·cm)和1.01×104L/(mol·cm);检出限分别为0.025mg/L和0.040mg/L;有色溶液的吸光度与Fe(Ⅲ)量在0.5～2.5mg/L、与Ni(Ⅱ)量在0.2～1.0mg/L范围内符合比耳定律,加标回收率为97.8%～103.5%(n=6)。本法较好地测定了非晶态FeNiCr合金钢中的铁和镍。

In HCl-KCl solution of pH= 1.0 and HCl-tris buffer solution of pH=8.0 and Tween80 non-ionic micelle medium containing polyoxyethylene groups, the chromogenic reactions of Fe(Ⅲ) and Ni(Ⅱ) with 1-nitroso-2-naphthol (NN) were studied respectively, based on which a novel micellar UV-Vis-spectrophotometric method was developed to determine trace Fe(Ⅲ) and Ni(Ⅱ). The results show that the maximum absorption wavelengths are at 445 nm for Fe(Ⅲ)-NN(pH=1.0) and at 455 nm for Ni(Ⅱ)-NN(pH=8.0), and the molar absorptivity is 1.68×104 L/(mol·cm) and 1.01×104 L/(mol·cm), respectively. The detection limits are 0.025 mg/L for Fe(Ⅲ) and 0.040 mg/L for Ni(Ⅱ), and Beer's law is obeyed for Fe(Ⅲ) in the range of 0.5~2.5 mg/L and for Ni(Ⅱ) in the range of 0.2~1.0 mg/L. The recovery of adding standard solution is 97.8%~103.5% (n=6). The method can be applied to determine the iron and nickel in amorphous FeNiCr alloy with satisfactory results.