三氧化铀中硝酸根的拉曼光谱定量分析

Determination of NO₃ in UO3 by Raman Spectroscopy

摘要: 本文建立了拉曼光谱法测定乏燃料后处理三氧化铀产品硝酸根含量的分析方法。选用乙酸为浸取剂和内标，NO₃在1048 cm−1处的拉曼峰与CH₃COO−在2948 cm⁻¹处的拉曼峰强度比与NO₃浓度之间呈现良好的线性关系，r² = 0.997。对于含有1 mol/L乙酸0.1 mol/L硝酸的混合溶液，6次检测的相对标准偏差不高于1.1%。在加入的乙酸量确定时，根据三氧化铀的样品量以及上述两个拉曼峰的强度比，可获得三氧化铀样品中硝酸根的含量值，方法的检出限为0.005 mol/L。该方法具有测定简单、方便快捷的优点。

Abstract: A new method via Raman spectroscopy for determination of NO₃ in Uranium trioxide was de-veloped. Acetic acid was selected as the leaching agent and the internal standard, and the concen-tration of NO₃ can be quantified by the Raman band of NO₃ (1048 cm⁻¹) and CH₃COO− (2948 cm⁻¹). A good linear relationship is obtained between the Raman Relative Intensity ratio of   and CH3COO− and the concentration of NO₃ in the range of 0.02~1 mol/L, with the r² = 0.997. The RSD was not more than 1.1% (n = 6) for detection of 0.1 mol/L HNO₃ with 1 mol/L acetic acid. When the amount of acetic acid added was determined, the concentration of nitrate in the Uranium trioxide sample could be obtained according to the amount of sample and Raman intensity ratio of these two substances. The detection limit was 0.005 mol/L. With the advantage of simple and rapid detection, this method is applicable for in-situ detection of NO₃ in Uranium trioxide samples.