二氧化铀中微量铍和钍的测定

DETERMINATION OF TRACE BERYLLIUM AND THORIUM IN URANIUM DIOXIDE

在三乙醇胺体系中，利用桑色素荧光光度法测定微量铍，当激发波长为４００ｕｍ时，铍－桑色素络合物的最大荧光波长为５２５ｕｍ，铍的标准曲线范围为０．０５～１．０μｇ／１０ｍＬ。在盐酸介质中，利用偶氮胂－ＴＢＣ分光光度法测定微量钍，钍的测定波长为６３５ｕｍ，标准曲线的范围为０．２～５．０μｇ／２５ｍＬ。利用ＣＬ－５２０９萃淋树脂进行了大量铀中微量铍和钍的分离。在１ｍｏｌ／ＬＨＮＯ３中，由于铀和钍的吸附，微量铍被定量分离，在１ｍｏｌ／ＬＨＣｌ＋１ｍｏｌ／ＬＮａＣｌ介质中，微量钍可被定量淋洗。二氧化铀样品中铍和钍测定结果的相对标偏优于５％。

In the triethanolamine solution system, trace beryllium is determined by fluorophotometry with morin. The maximum fluorescence wavelength is 525um for beryllium--morin complex with 400um in wavelength of excitation and the standard curve of beryllium is over the range of 0. 05-- 1. 0μg/10mL. In HCl solution system,trace thorium isdetermined by arsenazo--TBC spectrophotometry with 635um in wavelength. The standard curve of thorium is over the range of 0. 2-5. 0μg/25mL.Investigation of separating trace beryllium and thorium from a large amount of uranium has been reported,using levextrel resin CL--5209 as a stationary phase for chromatography.Uranium and thorium are adsorbed on the resin, while trace beryllium is separated quantitatively in 1mol/L HNO, solution. Thorium adsorbed on the resin can be eluted quantitatively with 1mol/L HC1+1mol/L NaCl solution,while a large amount of uranium is not.Beryllium and thorium in uranium dioxide sample are analysed with the RSD less than 5%.