新显色剂二溴邻硝基偶氮胂的合成及其与钍显色反应的研究

报道了新显色剂二溴邻硝基偶氮肿的合成方法,并研究了试剂与钍的显色反应。在0.12～1mol·L~(-1)HCl 介质中试剂与钍形成蓝色配合物。最大吸收在640nm 处。摩尔吸光率为9.7×10~4L·mol~(-1)·cm~(-1)。Th 在0～8μg/25mL 符合比耳定律。试剂对稀土、铀有很好的抗干扰能力。     

偶氮胂Ⅲ分光光度法测定镁含量

本实验通过利用分光光度计测定样品中微量镁的含量,本实验选定的显色剂为偶氮胂Ⅲ,其偶氮胂Ⅲ-镁的络合物最大吸收波长为λ=600nm。本实验对部分测定条件进行了摸索:最佳射入波长的选择、缓冲溶体系的酸度选择、缓冲溶液的用量、显色剂用量的最佳量、试剂稳定性的测定条件。在最佳实验条件下测定淀粉、蔗糖、自来水中的微量镁的含量。     

分光光度法测定水中钍的方法改进

本实验通过样品前处理时进行双氧水处理,萃取过程采用混合萃取剂,消化过程采用硝酸、高氯酸、过氧化氢进行联合消解,能有效降低复杂基质中有机质在分光光度法分析水中钍的干扰,能有效提高分析结果的准确性。     

2—羟基—3—羧基—5—磺基偶氮胂的合成及光度法测定钍的研究

研究了 2 -羟基 - 3-羧基 - 5 -磺基偶氮胂的合成及光度法测定钍的方法。在 1 .2 mol/L硝酸介质中 ,钍与 2 -羟基 -3-羧基 - 5 -磺基偶氮胂形成 1∶ 2的绿色配合物 ,最大吸收波长在 6 75 nm处 ,摩尔吸光系数为 8.5 4× 1 0 4 L· mol- 1·cm- 1 。钍含量在 0～ 30 μg/2 5 m L范围内符合比耳定律。应用于特种镁合金中钍的直接测定 ,结果非常满意。     

二溴邻硝基偶氮胂的纯化,性质及其钍络合物的稳定常数

研究了钍的新试剂二溴邻硝基偶氮砷（ＤＢＯＮＡ）的纯化方法和性质。测定的其离解常数（ｐＫａ）、质子化常数（ｌｏｇＫｐ）分别为１０．１７和－４．７５。求得钍络合物的组成为１：２，其积累稳定常数为２７．９８。     

对乙酰基偶氮氯膦与钍的显色反应及应用

本文以对乙酰基偶氮氯膦（ＣＰＡｐＡ）为显色剂，建立了钍的分光光度分析新方法。在０．１ｍｏｌ／Ｌ盐酸介质中，钍与ＣＰＡｐＡ生成配合比为１：２的蓝色配合物，最大吸收波长位于６７６ｎｍ，摩尔吸光系数ε_（ｍａｘ）＝７．６８×１０４Ｌ·ｍｏｌ~（－１）·ｃｍ~（－１），钍量在０～５５ｍｇＴｈＯ_２／２５ｍｌ范围内遵守比耳定律，方法已用于水样中钍的测定。     

滑石粉中放射性核素铀钍测定方法的研究

介绍了一种测定滑石粉中放射性核素铀钍的简便、快速且灵敏的方法。     

硅质材料中硼含量测定方法的研究

本文建立了采用铍试剂Ⅲ分光光度法测定硅质硅质nationertometry材料中硼元素的含量的方法,该方法可用于多种硅酸盐材料中硼含量的分析,测定值符合标准要求值。通过对硅质土壤标准物质中硼含量的测定,方法具有准确度爵、检出限低、分析速度快、操作方便等优点,加标回收率95％～102％,相对标准偏差小于3．8％。     

偶氮胂Ⅲ分光光度法测定玻璃中的氧化铈

介绍了玻璃中氧化铈的分光光度测定方法。铈(Ⅳ)与偶氮胂Ⅲ形成有色配位化合物,最大吸收波长为660 nm,摩尔消光系数为5.21×10~(-4) L·mol~(-1)·cm~(-1),铈与偶氮胂Ⅲ之间的摩尔比为1∶1,方法回收率为96%～105%,标准偏差为0.31%。     

偶氮胂Ⅲ分光光度法测定玻璃棉中的铬含量

研究了铬(Ⅲ)与偶氮胂Ⅲ的显色反应。在pH等于2.0～2.5的酸性介质中,100℃水浴条件下,铬(Ⅲ)与偶氮胂Ⅲ形成1:1的紫色水溶性配合物,最大吸收波长为610nm,表观摩尔吸光系数为1.97×104L.mol-.1cm-1。铬的质量浓度在0～60μg/50mL范围内符合比尔定律,相关系数r=0.9985。研究了共存离子的影响和消除方法。本方法用于玻璃棉中的铬含量的测定,加标回收率为95.2%～103.1%,相对标准偏差小于3.4%,符合分析要求。     

ICP-AES法测定煤中钒、钍

煤中微量元素的开发利用日益受到重视。探讨了用ICP-AES法测定煤中钒、钍,对仪器工作条件、测定步骤、所用试剂、加标试验、对比试验作了介绍,结果表明,该法测试煤中钒、钍,其精密度在5%,加标回收率在95%～105%之间,与化学方法相比,更准确、快速。     

电感耦合等离子体质谱法测定水中铀、钍

以Bi为内标,用等离子体质谱法同时灏定水中铀、钍元素的含量,优化了仪器工作条件。铀、钍的方法检出限分别为0．3、1．2ng／L,线性相关系数均〉0．999,对O．5000μg/L的铀、钍标准溶液测定的相对标准偏差分别为3．33％、3．03％,基体加标回收率为95％-106％,方法准确可靠。     

抑汗类化妆品中锆的测定方法研究

建立了偶氮胂Ⅲ分光光度法测定化妆品中锆的含量。考察了显色剂用量、显色时间、显色温度以及共存离子对吸光度的影响,优化了测定条件。结果表明,室温下显色30 min,吸收波长664 nm处,锆的线性范围为2~10 mg/L,相关系数R~2=0.999 9,方法检出限为59 mg/kg,定量限为72 mg/kg,RSD=3.23%,回收率为88.8%~109.2%。常见共存离子K~+、Na~+、Ba~(2+)、Sb~(3+)、Pb~(2+)等对测定锆无干扰。该方法可靠、准确,适用于化妆品中锆的测定。     

Thorium Uptake on Synthetic Inorganic Ion Exchangers

Birnessite, antimonysilicate, and their cation-exchange derivatives were tested to take up thorium. Sorption experiments were performed in different concentrations of acid, sodium, potassium, and calcium nitrate solutions in order to evaluate the influence of cations that are likely to be present in waste effluents. Variation in the magnitude and mechanism of thorium sorption on the exchangers was ascribed to structural differences and the exchange properties of the materials, as well as the aqueous chemistry of thorium. The work included investigation of thorium solution' pH in controlling the sorption process. In acidic solutions, H-antimonysilicate proved to be the best sorbent. The structure of M-H-birnessite allows facile mobility of the interlayer cations with little structural rearrangement, making it of great importance for ion-exchange use in salt conditions. Potassium had the most, and sodium the least effect on thorium selectivity by birnessites, when they are present as macro components. Conversely, calcium ions did greatly inhibit the sorption behavior of thorium on Ca-antimonysilicate. Studying the effect of thorium solution' pH reflected the fact that the microcrystal modifications of birnessites occurred during experiments. In summary, H-birnessite showed superior uptake for thorium in comparison to other materials investigated in the literature, which reflects the characteristics of the material selectivity.     

Recovery of Thorium by High-Capacity Biopolymeric Sorbent

The potential of prepared alginate biopolymers as a natural, economic, effective, non-toxic biosorbent was investigated for the recovery of thorium ions in this study. The experiments were carried out to study the effects of various physico-chemical parameters on biosorption and desorption of thorium. The biosorption process was examined by various isotherm models and equilibrium data were successfully described by a Langmuir model very well. The monolayer biosorption capacity was found as 169.50 mg/g. The thermodynamic parameters such as variations of enthalpy, entropy, and Gibbs free energy for thorium biosorption were also defined and the results suggest that endothermic nature of the process. The prepared alginate biopolymers exhibit high uptake capacity and regeneration potential for biosorption of thorium.     

The Recovery of Trace Thorium from Large Quantities of Uranium

This work describes the chromatographic separation of trace amounts of Thorium (mg or less) from large quantities of Uranium (g or kg). The separation method employs extraction chromatographic materials containing tetra(n‐octyl)diglycolamide (TODGA) and quaternary amine extractants. Applications of this separation include isolation of ²³⁴Th from ²³⁸U and ²²⁹Th from ²³³U. ²³⁴Th could be a useful radiotracer, providing a continuous supply of radiothorium from natural or depleted uranium, while ²²⁹Th is the source material for ²²⁵Ac and ²¹³Bi, radionuclides with promising applications in nuclear medicine.     

Modeling of the Permeation of Thorium through Liquid Emulsion Membrane

Abstract

A general permeation model for the separation of thorium by liquid emulsion membrane (LEM), using theonyletrichloroacetone HTTA as a carrier is presented. The internal mass transfer in the W/O emulsion drop, the external mass transfer around the drop, the rates of formation, and the decomposition of the complex at the external aqueous‐organic interface were considered. Further, the leakage of the internal aqueous phase to the external phase due to the membrane break‐up is also taken into account. The batch extraction of thorium using HTTA as a carrier was carried out under various experimental conditions. It is found that the extraction rates can be satisfactorily simulated by the proposed model.     

1,2,3-三羧甲氧基苯的催化合成及其与钍的显色反应

以三丁基乙基硫酸乙酯铵为相转移催化剂 ,用焦性没食子酸、一氯乙酸和氢氧化钠为原料 ,合成了一种新的钍分析试剂——— 1,2 ,3-三羧甲氧基苯 (TCMOB)。显色试验表明 ,TCMOB是一种性能优良的钍显色剂 ,在 2 5ml 4mol/L的HClO4 介质中形成 1∶1的配合物 ,其最大吸收峰位于 32 5nm ,吸光系数为ε4 2 5nm =8.86× 10 4 L·mol- 1·cm- 1,钍的含量在 0～30 μg/ 2 5ml范围内符合比尔定律     

偶氮胂显色剂离解常数及其与镧配合物稳定常数的测定

用分光光度法和电位滴定测定了部分偶氮胂显色剂的离散常数,与已报道偶氮膦显色剂进行了比较。测定了与稀土镧元素的稳定常数,讨论了取代基种类及位置的影响。