偶氮氯膦-mA分光光度法测定水相中微量钍

目前,用于分光光度法测定微量钍的显色剂不少,常用的有钍试剂、偶氮胂Ⅰ、偶氮胂羧、偶氮胂Ⅲ和偶氮氯膦Ⅲ。其中偶氮胂Ⅲ为最常用的显色剂,该显色剂只有在中等酸度下测钍才具有较高的灵敏度。其它显色剂在低酸介质中测钍时灵敏度并不理想。偶氮氯膦-mA是由上海师大于1979年首先合成并应用于稀土元素分析的新型显色剂,它为深紫红色结晶粉末,易溶于水,在酸性介质中与钍形成蓝紫色络合物,其结构式如下:     

新显色剂——偶氮胂-TBC分光光度法测定钍的研究

文章研究了新显色剂偶氮胂-TBC分光光度法测定钍的各种条件。在0.2—0.7 mol/l硝酸介质中,该试剂与钍形成稳定的红色络合物,其最大吸收峰在632 nm处,络合物摩尔吸光系数达1.02×10~5l.mol~(-1)cm~(-1),比尔定律适用范围宽,最低检测浓度达0.2μg/25ml。一些常见元素的干扰很小。用拟定的方法测定了几种矿石中的钍,其结果很令人满意。     

偶氮氯膦-mA分光光度法直接测定有机相中微量钍

本文研究了钍萃取工艺过程中微量钍的测定方法。在0.5 N HNO_3介质中,用乙二醇丁醚作互溶剂,该均相溶液用偶氮氯膦-mA作钍的显色剂,进行分光光度法直接测定有机相中微量钍。波长670 nm处呈现最大吸收。摩尔消光系数达1.0×10~5,0-12μgTh/10ml符合比耳定律。该体系中仅可允许适量铀存在,随铀量增加误差增大。     

分光光度法测定模拟裂片元素料液中的微量钍

一、前言用梯形波脉冲筛板萃取柱回收强放废液中镎的实验研究中,以Th~(4 )模拟Np~(4 )在萃取柱中的传质行为需要测定以下两种料液中的钍含量:     

应用偶氮氯膦-mA分光光度法测定水相中微量铀

目前用于分光光度法测定铀的显色剂不少,常用的有铀试剂Ⅲ,CPAⅢ,PADAP,Br-PADAP及TAR等,而在微量铀分析上应用最广的是铀试剂Ⅲ和Br-PADAP两种。     

用二阶导数分光光度法同时测定铀和钍

木文研究了以4-(2′—噻唑偶氮)二羟基苯乙酮肟作试剂,用二阶导数分光光度法同时测定铀和钍,该法可测定0×10~(-6)—10.0×10~(-6)的铀和钍,相对误差<4％。普通阴离子和阳离子即使大量存在也不干扰测定。然而,过渡金属离子即Cu、Nu、Pd和Pt容限<100×10~(-6)。     

离子交换法分离／分光光度法测定四氟化铀中的微量钍

采用硝酸－过氧化氢溶解ＵＦ４，离子交换法分离去除干扰元素，分光光度法测定样品中的微量钍。在１０ｍＬ试样中，钍含量在０—１．０μｇ范围内符合比尔定律，相对标准偏差小于４．５％，样品重加回收率为９６．７％—１０３％。     

偶氮氯磷Ⅲ双波长分光光度法同时测定铀矿石中钍和铀

对偶氮氯膦Ⅲ和钍、铀在磷酸体系中的显色行为作了研究,提出以TRPO-G.D.X-301萃取色层分离稀土、钛、锆等干扰元素、用双波长分光度法同时测定铀矿石中钍和铀的方法。测定钍和铀时,测量波长、参比波长分别为690nm、608nm和670nm、707nm,工作曲线在0～50μg/25ml内成线性。测定矿石中0.03%～0.5%的钍和铀时,误差小于10%。本法可用于复杂样品中钍和铀的同时测定。     

5-Br-PADAP分光光度法测定钍中微量铀

一、引 言 随着核能的发展,钍在核能中的应用正日益受到世界各国的重视。钍基核燃料辐照后转化为~(233)U,在后处理钍铂分离净化过程中需要测定常量钍存在下的微量铀。目前常量钍中铀的分析通常采用离子交换或TBP多次萃取-反萃分离,然后用分光光度法测定,但由于上     

活性炭吸附-分光光度法快速测定人尿中的微量钍

一、前言用作增殖核燃料的钍属高毒放射性元素,因而对钍作业人员需进行剂量监测。尿钍值可为估算其所受内照射剂量提供基本数据。在健康普查、临床诊断、事故处理、药物促排中均是一项重要的检验指标。目前,测定尿钍首推中子活化分析法最灵敏,但一般实验室皆受条件所限而不可行。本实验建立了在普通实验条件下,快速灵敏地测定作业人员尿钍值的简便方法。尿样勿需     

DBN－偶氮胂在微量钍的分光光度测定中的应用

以ＤＢＮ－偶氮胂作为微量钍的分光光度测定的显色剂。结果表明，在１ｍｏｌ／ＬＨＣｌ溶液中，ＤＢＮ－偶氮胂和钍的络合物在λ＝６３０ｎｍ处的表观摩尔吸光系数为８．６×１０４Ｌ·ｍｏｌ－１·ｃｍ－１，并且可在高达９０倍的铀存在下测定微克级的钍。在０—１３μｇＴｈ／１０ｍｌ范围内符合比耳定律，标准曲线线性良好，相关系数ｒ＝０．９９９１。在３０％ＴＢＰ－煤油溶液中采用互溶法，可用ＤＢＮ－偶氮胂直接测定微量钍。采用乙二醇丁醚为互溶剂，显色剂和钍的络合物稳定性仍能满足要求，比耳定律适用范围不变，标准曲线线性良好。     

两种测定铀、钍含量方法的比较

用中子活化分析和厚源α－计数两种方法测定了５１个唐三彩马的铀和钍含量，并对结果进行了比较。在采用厚源α－计数法技术来决定铀和钍对标本提供的年辐射剂量时，可以用总α－计数率来计算。     

偶氮氯磷mN-钍络合物在光度分析中的应用

新型显色剂2-(4-氯-2-膦酸基苯偶氮)-7-(3'-硝基苯偶氮)-1,8-二羟基-3,6-萘二磺酸(简称偶氮氯膦mN)属于不对称变色酸双偶氮膦酸型衍生物,该试剂为深紫红色的结晶粉末,易溶于水,是稀土元素高灵敏度的显色剂~([1])。用该试剂以光度法分析的方法已用于矿物、合金中铈组稀土元素和稀土总量的测定~([2-5]),它具有灵敏度高、显色酸度高、对比度大、所形成的络合物十分稳定、能在较宽的范围内符合比耳定律等优点。目前,用这     

Synthesis of thorium sol for fabricating fuel kernels

To fabricate thorium-based fuel kernel for solid fuel molten salt reactor,a component of tri-structural isotropic fuel particles is mostly based on sol-gel method.The preparation of thorium sol is an important step for fabrication of thorium-based fuel kernels,such as thorium carbide and thorium oxide.The gel quality affects the gel particle dispersion and the final products.In this work,thorium sols were prepared using Th(NO_3)_4 and NH_3·H_2O by sol-gel method.The effects of thorium concentration,mole ratio of NH_4~+/NO_3~- and reaction temperature on the pH,viscosity,turbidity,particle size and the thorium sol distribution were investigated.The results show that the viscosity and turbidity increased with the NH_4~+/NO_3~- ratio;the turbidity and colloidal particle size increased with the reaction temperature,which affected little the sol viscosity;the sol viscosity increased with the thorium concentration,which virtually did not change the turbidity;and the particle size decreased and the size distribution narrowed with increasing thorium concentration.The sol could be stored at room temperature for one day without significant property changes.Thorium gel spheres of good quality were prepared at 60℃ with the NH_4~+/NO_3~- ratio of 75-85% and the thorium concentration of 1.2-1.4 mol/L.     

Evaluation of implementation of thorium fuel cycle with LWR and MSR

In order to construct a sustainable society, it is necessary to consider fairness beyond generations and between countries. It is expected that Asian countries continue growing their economy and will result consuming more energy. More CO₂ emission is not acceptable.Nuclear power has many advantages for reducing CO₂ emission. However, it still has concerns of nuclear proliferation, radioactive waste and safety. It is necessary to overcome these concerns if nuclear power is expanded to Asian countries. Thorium utilization as nuclear fuel will be an opening key of these difficulties because thorium produces less plutonium, less radioactive waste. Safety will also be enhanced. The use of molten-salt reactor (MSR) triggered by plutonium supply from ordinary light water reactor (LWR) with uranium fuel will allow implementation of thorium fuel cycle with electricity capacity of about 446 GWe around at 2050.The other important sector in a view of sustainability is transportation. Transportation is essential for economy growth. Therefore it is inevitable to reduce CO₂ emission from transportation sector. Electric vehicle (EV) will be used as a major mobility instead of gasoline engine cars. Rare-earth materials such as neodymium and dysprosium are necessary for producing EV. These materials are expected to be mined from Asian countries. It is often obtained with thorium as by-product. Thorium has not been used as nuclear fuel because it is not good for nuclear weapon and it does not have fissionable isotopes. Recent global trend of nuclear disarmament and accumulation of plutonium from uranium fuel cycle can support starting the use of thorium.Thorium utilization will help both to provide clean energy and to produce rare-earth for clean vehicle. These will create new industries in developing Asian countries. An international collaborative framework can be established by supplying resource from developing countries and supplying technology from developed countries. “THE Bank (THorium Energy Bank)” is proposed here as one part of such a framework.