溶液制样—波长色散X射线荧光光谱法测定天然铀产品中的铀含量

Determination of Uranium Content in Natural Uranium Productsby X-ray Fluorescence Spectrometry

采用溶液制样,以碳酸锶为内标物,建立了用波长色散X射线荧光光谱法测定天然铀产品(U_(3)O_(8))中铀含量的方法。样品称样质量为1.00 g,内标物碳酸锶称样质量为0.600 g,采用15 mL磷酸和2 mL硝酸消解样品,定容至200 mL后,用磁力搅拌混匀,采用一次性塑料吸管和电子秤控制取液体积。仪器测量条件选择特征X谱线:U-L_(α1),Sr-K_(α1),通道面罩34 mm,初级准直器150μm。该方法工作曲线的线性相关系数为0.999 8,相对标准偏差(RSD)为0.031%~0.050%,精密度较好;测定结果与标准物质推荐值之间的相对误差不劣于0.034%,准确度较好。与电位滴定法对比,该法绝对偏差为0.010%~0.126%,结果准确可靠,能够满足天然铀产品快速批量分析的要求。

A method for determining uranium content in natural uranium products(U_(3)O_(8))by wavelength dispersive X-ray fluorescence spectrometry was established using solution sample preparation and strontium carbonate as the internal standard.The method determines that the weight of the sample is 1.00 g,and the weight of the internal standard strontium carbonate is 0.600 g.The sample is digested with 15 mL of phosphoric acid and 2 mL of nitric acid to a constant volume of 200 mL.After stirring with magnetic force,the volume of the solution is controlled using a disposable plastic pipette and an electronic scale.Instrument measurement conditions selection feature X-ray line:U-L_(α1),Sr-K_(α1),channel mask 34 mm,primary collimator 150μm.The linear correlation coefficient of the working curve of the method is 0.9998,and the relative standard deviation(RSD)is between 0.031%and 0.050%,indicating good precision;The relative error between the measurement results and the recommended value of the reference material is not less than 0.034%,with good accuracy.Compared with the potentiometric titration method,the absolute deviation of this method is between 0.010%and 0.126%,and the results are accurate and reliable,meeting the requirements for rapid batch analysis of natural uranium products.