分光光度法测定二氧化铀中微量硝酸根

Spectrophotometric Determination of Trace Nitrate Ion in Uranium Dioxide

摘要: 基于硝酸根离子对靛蓝二磺酸钠(IC)的褪色反应，建立了一个简单、快速、选择性好的二氧化铀产品中硝酸根离子的测定方法。在610 nm波长处，NO₃^－在0.20～1.00 mg/L 范围内与靛蓝二磺酸钠吸光度的减小值呈线性关系，线性回归方程为y=0.297 5x +0.020 5, r= 0.999 39，相对标准偏差(s_r)优于10%，加标回收率在93%～106%。该法可用于测定二氧化铀产品中微量NO₃^-，操作简单，可行性强，可以满足测定要求。

Abstract: A simple, fast and selective spectrophotometric method for the determination of trace nitrate ion in uranium dioxide was developed, based on the fade of indigo carmine(IC) with nitrate ion in sulfuric acid medium. The visible absorbance is detected at a wavelenth of 610 nm. The linear calibration range is 0.20-1.00 mg/L. The linear equation and the correlation coefficient are y=0.297 5x+0.020 5 and 0.999 39 respectively. The relative standard deviation is less than 10%, and the standard addition recovery of nitrate ion is 93%-106%. The method is applied to the determination of nitrate ion in uranium dioxide sample with satisfactory results.