【摘要】 <正> 一、前言本工作系六氟化铀水解溶液中痕量⁹⁹Tc的测定。定量测定⁹⁹Tc有各种方法,但通常多采用简便的β放射性测量法和分光光度法。⁹⁹Tc是一个纯β放射体,其比活度较高(3.78×10¹⁰Bq/min·g)。在UF₆产品中,除了大量铀、氟外,其它杂质和干更多还原

【Abstract】 An analytical method was recommended in this paper. The ⁹⁹Tc was extrac-ted from the Na₂CO₃ solution containing large quantities of uranium and fluorineusing methyl ethyl ketone as an extractant and was determined by counting its β-particules. The extractive characteristics of methyl ethyl ketone, 2,6--dimethylpyridine,tetraamine--7402 and methyl isobutyl ketone and the effect of the time of equili-brium and of the concentrations of carbonate, uranium and fluorine in the aqueoussolution on the extraction and the removal of radioactive impurities werestudies. Samples of UF₆ were analysed and the results were compared using threecounting devices （liquid scintillation counter, low background counter, with abackground of only 1.5--2 cpm and ordinary GM counter, with a background ofabout 30 cpm）. The results indicated that the three devides was satisfactory for the countingwhen the quantities of ⁹⁹Tc was more than 0.25μg in 100 mg U samples. The method is simple, ripid and sensitive. The relative standard deviation for10 parallel samples is 2.5%. The percentage recovery is 98--101%. The decon--tamination factor for the removal of the radioactive impurities is more than 1×10³.更多还原