Indirect automatic atomic absorption determination of sulphate based on its precipitation with barium

A continuous precipitation flame atomization atomic absorption spectrometric method for the indirect determination of sulphate is proposed. By using a reversed flow-injection configuration for precipitation as barium sulphate, this anion was determined in the range 10–150 g/ml, with a relative standard deviation of 2.6%. The sensitivity was increased by a factor of seven by using a nitrous oxide-acetylene flame to measure barium.     

硫酸根的分光光度法测定

本文就硫酸根的间接及直接光度测定的基本原理，试剂，方法和应用等作了较为系统的评述。列出重要文献６７篇。     

差热分析(DTA)法研究五水硫酸铜的失水过程

关于五水硫酸铜的失水过程有不同的说法。归纳起来,主要有以下几种:1.五水硫酸铜的失水过程分三步进行,即     

DSC Investigations of DDAB,DTAB and DHAB Vesicle Aqueous Solutions in Presence of SDS

Interactions of anionic surfactant sodium dodecyl sulphate (SDS) with vesicles formed by synthetic dialkyldimethylammonium bromides i.e. didodecyldimethylammonium bromide (DDAB), ditetradecyldimethylammonium bromide (DTAB), dihexadecyldimethylammonium bromide (DHAB) have been examined by using differential scanning microcalorimetry and electron transmission microscopy. The temperatures and standard enthalpies characterising gel to liquid-crystal transitions increase significantly with increase of SDS concentration for all investigated systems. It means that incorporation of SDS monomers in these vesicular bilayers significantly stabilises their gel states. Moreover, in case of DDAB and DTAB vesicle systems added SDS limits kinetic features of recorded isobaric heat capacity dependencies on temperature observed earlier for the pure vesicular solutions. This revised version was published online in July 2006 with corrections to the Cover Date.     

电极条件对硫酸介质中电解还原提纯镱过程的影响

研究了以钌铱钛合金网和汞分别为阳、阴电极, 在无气氛保护条件下, 采用电解还原方法从铥、镱、镥硫酸盐溶液中分离提纯镱的过程. 讨论了在8 V恒电压时的电极间距、位置, 以及阴、阳极表面积对电解过程中的电流、还原率影响. 优化了电解还原过程, YbSO4产品的纯度稳定达到99.5%以上, 一次收率可达80%;提镱后母液中的铥和镥被富集4倍以上, 其中Lu含量高于50%, 十分有利于后续铥/镥分离.     

聚合硫酸铁絮凝剂碱度的测定

聚合硫酸铁(PFS)是一种新型高效无机高分子絮凝剂,近年来在生产、生活用水和废水处理上得到日益广泛的应用。PFS的主要成分为碱式硫酸铁的聚合物,化学式可表示为[Fe_2(OH)_n(SO_4)_(3-n/2)]m,其中,n<2,m>10.分子式中的羟基为分子聚合提供氢键,并使PFS具有宽广的pH应用范围。因此,碱度是聚合硫酸铁絮凝剂生产和使用的一个重     

Extraction of uranium(IV) and uranium(VI) by primary and tertiary-amines from sulphate solutions

In developing a method for possible low level isotopic enrichment, which uses to advantage the equilibrium isotope effect observed during U(1V)-U(VI) electron exchange reaction in sulphate solutions, details of a solvent extraction process involving high concentration of a mixture of U(IV) and U(VI) and at low acid concentrations, are described. The extraction behaviour of uranium under these conditions is discussed. During the extraction with amines, U(IV) tended to get oxidised in sulphate solutions.     

硫酸喹啉荧光猝灭法测定脱氧核糖核酸

基于DNA在pH2～4的范围内对硫酸喹啉的荧光具有较强的猝灭作用，建立了一种测定DNA的新方法。当DNA的浓度为10～700μg／L时，荧光猝灭程度与DNA浓度呈线性关系，其线性回归方程为：△IF=1．52118 0．11038G(μg／L)；相关系数r=0．9985；检出限为5．9μg／L。本方法用于大肠杆菌提取的质粒DNA的测定，获得满意结果。     

Reaction of sulphate radical anion (SO<Superscript>.</Superscript><Subscript>4</Subscript><Superscript>-</Superscript>) with hydroxy-and methyl-substituted pyrimidines: a pulse radiolysis study

Reactions of sulphate radical anion (SO·₄ ^-) with 4,6-dihydroxy-2-methyl pyrimidine (DHMP), 2,4-dimethyl-6-hydroxy pyrimidine (DMHP), 6-methyl uracil (MU) and 5,6-dimethyl uracil (DMU) have been studied by pulse radiolysis at pH 3 and at pH 10. The transient intermediate spectra were compared with those from the reaction of hydroxyl radical (·OH). It is proposed that SO·₄ ^- produces radical cations of these pyrimidines in the initial stage. These radical cations are short-lived except in the case of DMHP where a relatively longer lived radical cation is proposed to be formed. When there is a hydrogen atom attached to the N(1) or N(3) position, a deprotonation from these sites is highly favored. When there is no hydrogen attached to these sites, deprotonation from a substituted methyl group is favored. At acidic pH, deprotonation from nitrogen is observed for DHMP, MU and DMU. At basic pH, the radical cation reacts with OH^- leading to the formation of OH adducts.     

Physicochemical study of ovalbumin in the presence of sodium dodecyl sulphate in aqueous media

The interactions of sodium dodecyl sulphate with ovalbumin in aqueous solution at room temperature are described for a wide concentration range of both substances. A phase diagram covering a wide range of concentrations shows a total of five different morphologies. Dynamic light scattering of the samples from each morphology offered better understanding of the different structures (between three and four) present in the solution. The amount of ovalbumin present in the solution was confirmed with differential scanning spectroscopy, while the interactions between sodium dodecyl sulphate and ovalbumin were interpreted by zeta potential and electrical conductivity measurements.