摘要
在精密测定铀含量的过程中,滴定剂浓度太低或太高均对测定结果的精密度有影响,且存在电极响应迟缓及电位拖后现象,从而影响铀含量测定结果的准确度和精密度。为克服这些不利因素,建立一种溯源链清晰,结果准确、可靠的精密测定小量铀的方法尤为重要,对铀标准物质的研制及铀样品的精密分析具有重要意义。本文以异戊醇为萃取剂,对Cr(Ⅵ)与显色剂二苯卡巴肼(DPC)生成的紫红色配合物进行了萃取实验研究,并确定了最佳萃取条件,建立了萃取光度法精密测定铀含量的方法。铀取样量为100mg时,相对标准偏差为0.025%。
In the conventional method of potentiometric titration,the concentration of potassium dichromate solution was optimized with selection of different concentrations of the solution.The electrode responded slowly during the titration procedure,thus affected the precision and accuracy of the results.An extraction spectrophotometric method for accurate and precise determination of uranium was presented.The method was based on the extraction of Cr（Ⅵ）-diphenylcarbazide purple complex using iso-amyl alcohol as the extractant.The purple complex was directly measured at 546nm so that the uranium-chromate equivalence point can be determined.A method for precise determining uranium by extraction spectrophotometry was developed.The China national reference material of U3O8（GBW04205）was determined according to the optimized experimental conditions.The relative standard deviation is 0.025%and accuracy of the method is verified by the value of China national reference material of U3O8.
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
2011年第8期915-919,共5页
Atomic Energy Science and Technology
