钪-稀土-对乙酰基偶氮氯膦体系共显色效应的研究

钪－稀土－对乙酰基偶氮氯膦体系共显色效应的研究刘双成,徐钟隽,潘教麦（华东师范大学化学系,上海,２０００６２）关键词钪,稀土,对乙酰基偶氮氯膦,共显色效应不则称偶氮氯膦试剂与稀土元素的β型显色反应,已被广泛用于稀土的测定［１,２］．但是当多种稀土或某...     

钪（Ⅲ）—对氯偶氮氯膦—L三元配合物显色体系的研究与应用

提出了钪（Ⅲ）－对氯偶氮氯膦－Ｌ三元配合物显色体系，并对其显色条件及第二配位体Ｌ对该显色体系的影响等问题进行了系统的研究。同时测定了配合物的组成比、带电性及共存离子的影响。推测了该三元络合物的可能结构。钪含量在０￣７．５μｇ／２５ｍＬ服从比尔定律。表观摩尔吸光系数为１．５２×１０＾５Ｌ·ｍｏｌ＾－１·ｃｍ＾－１。采用该三元体系测定了钒钛磁铁矿中的微量钪，结果满意。     

微纳米稀土氯氧化物的合成研究进展

稀土氯氧化物作为一种重要的发光基质,具有较高的光吸收效率和传能效率,在彩色显示、催化、生物医药、光电转换、气敏等领域均有广泛的应用,已成为光功能材料领域的研究热点之一。目前研究者已用固相法、沉淀法、液相-高温焙烧法、水热与溶剂热法、前驱体热解法、溶胶-凝胶法、静电纺丝法等方法成功地制备了稀土氯氧化物微米颗粒,纳米颗粒、纳米条、纳米片、纳米棒、纳米针、纳米纤维、纳米带、纳米管等稀土氯氧化物微纳米材料。总结了各种制备方法的研究进展及优缺点,并结合本课题组在稀土氯氧化物纳米材料方面的研究工作,对稀土氯氧化物微纳米材料的制备方法的发展方向进行了展望。     

岩石中稀土总量及钪、钍的连续萃取测定

PMBP作为萃取剂已广泛用于日常分析。本文在已有工作的基础上,试验了稀土、钪、钍的PMBP-乙酸丁酯的萃取、反萃取条件及其与共存元素的分离,确定了在同一份溶液中连续萃取稀土、钪、钍,然后用偶氮氯膦mN(CPA-mN)光度法测定稀土和钪,用偶氮胂Ⅲ测定钍。由于反萃溶液与测定溶     

镧-间硝基偶氮氯膦-钇体系共显色效应研究

变色酸双偶氮衍生物与稀土反应的共显色现象产生的原因,目前一种观点认为是在体系中生成了一种具有固定组成的异多核配合物,而另一种观点则认为是由于一种较快速的β型显色反应诱导并加速了另一种较慢速的β型显色反应所致。 间硝基偶氮氯膦(CPAmN)能与镧、钇和钪发生α、β型显色反应。本研究选定     

钪与偶氮氯膦Ⅲ的显色反应

钪与偶氮氯膦Ⅲ显色反应表明显色体系的吸收光谱有三个吸收峰,分别位于623、697和770nm处,并有相应的γ、α和β型配合物生成。初步探讨了该反应的特殊性。     

钪—间氯偶氮安替比林络合物吸附波的研究

在ＰＨ４．３０的ＨＡｃ－ＮａＡｃ介质中，钪－间氯偶氮安经林－硫氰酸钾生成三元络合物，于－０．３５Ｖ处出现一尖锐的极谱峰，峰电流与钪离子浓度在０．０２０－０．２０μｇ／ｍＬ范围内呈线性关系，检出限为０．０１０μｇ／ｍＬ。     

钪－间氯偶氮安替比林络合物吸附波的研究

在ｐＨ４．３０的ＨＡｃ－ＮａＡｃ介质中，钪－间氯偶氮安替比林（ｍ－ＣＡＡ）－硫氰酸钾生成三元络合物，于－０．３５Ｖ（ｖｓ．ＳＣＥ）处出现一尖锐的极谱峰，峰电流与钪离子浓度在０．０２０～０．２０μｇ／ｍＬ范围内呈线性关系，检出限为０．０１０μｇ／ｍＬ．用多种电化学方法研究了极谱波的性质及电极反应机理．方法用于矿样中钪的测定，结果满意     

钪—镧—对氟偶氮氯膦体系共显色效应的研究及应用

本文研究了钪－镧－对氟偶氮氯膦体系共显色效应的光度特性及测定钪的最佳条件，建立了光度法测定痕量钪的新方法。该法的表观摩尔吸光系数为８．５７×１０＾４Ｌ·ｍｏｌ＾－１·ｃｍ＾－１，Ｓｃ（Ⅲ）浓度在０．０－５．０μｇ／２５ｍｌ范围符合比尔定律。将本法用于镁基，铁基合成试样中痕量钪的测定，结果满意。     

对溴偶氮氯膦流动注射分光光度法测定岩矿中的钪

本文研究了对溴偶氮氯膦与钪在盐酸介质中的显色反应。在波长740nm,络合物的摩尔吸光系数为7.0×10~4,7～18μg Sc_2O_3/25ml符合比尔定律。采用流动注射分光光度法,联合使用微型计算机,测出工作曲线的线性范围为5～45μg Sc_2O_3/25ml,比普通分光光度法扩大1.5倍。应用于测定岩矿中的微量钪,方法快速、准确。     

Study on the cocolouration effect in the β-complex formation reactions of rare earths with p-chloro-chlorophosphonazo (CPApC)

Terbium- and yttrium-group rare earths form β-complexes with CPApC in acidic medium.The sensitivities for determination of these rare earths by this reaction depend on their ionic radii.Cerium- or terbium-group rare earth in the presence of yttrium-group element produces the cocolourationeffect which remarkably sensitizes the reaction. Yb-CPApC-Eu complex has a molar composition of1:4:2 and gives a molar absorptivity of 2. 02 ×10~5 L·mol~(-1)·cm~(-1) at 746 nm for Eu. It is found thatthe closer the lengths of ionic radii of the rare earths are, the greater will be the cocolouration effect.     

Dosage par activation neutronique des terres rapes dans des roches uraniferes

The determination of rare earths by activation analysis in uranium containing rocks is disturbed either by fission-produced rare earths, or by neptunium-239 originating from uranium-238. In order to eliminate of these interferences the chemical separation of rare earths from uranium prior to activation should be performed. The purpose of this work was the elaboration of a chemical process to separate rare earths prior to irradiation in a nuclear reactor. The rock sample is fused with sodium borate, then, after addition of hydrochloric acid, the resulting solution is passed through a Dowex 1×8 column. Uranium is retained on the resin and rare earths and scandium are eluted. Aluminium is added as a carrier to the solution and rare earths and scandium are coprecipitated with aluminium hydroxide. This precipitate is irradiated in the nuclear reactor. Gamma spectrometry is used for the determination of each radionuclide. Activities measurements are performed in successive steps during one month. The following elements are determinated: Pr, La, Sm, Nd, Yb, Lu, Ce, Tb, Eu, and Sc. The chemical yield is measured by using scandium as an internal standard.     

Present state of complexometry-IV Determination of rare earths

A review of the visual complexometric determination of the rare earths, scandium and yttrium with various volumetric reagents is presented. As in previous parts attention is paid to the complexometric behaviour of these metals and to the problems of interferences in their determinations. Methods for the determination of thorium, scandium and some rare earths in mixtures are described in detail. Recent developments and further possibilities in this field are discussed.     

Nachweis von scandium,seltenen erden,zirkonium und thorium mit murexid

The author describes the reactions of scandium, the rare earths, zirconium, and thorium with inurexid, as well as a qualitative method for the detection of scandium with the same reagent. A titrimetric method for the determination of scandium with murexid and nitrilotriacetate is proposed.     

Determination of rare earths in selected rare earth matrices by spark source mass spectrometry

Three methods of preparing rare earth samples for mass spectrographic analysis are presented. Techniques for adding appropriate internal standards are described and relative sensitivity factors for rare earth impurities in rare earths, lanthanum, yttrium and scandium matrices are presented. Although indium has some value as an internal standard in rare earth samples, best analytical results are obtained when selected rare earths are used as internal standards.     

对-乙酰基偶氮胂作淋洗剂阳离子交换分离及光度测定钍与稀土(铀、钪)

本文提出用显色剂--对-乙酰基偶氮胂作淋洗剂,阳离子交换分离钍与稀土(铀、钪),流出液可直接用光度法测定,将分离和测定结合起来的新方法.操作较简便快速.分离测定了矿石中稀土及钍,结果尚属满意.     

Selective determination of yttrium in geological materials by ion-interaction chromatography

Selective separation and determination of yttrium in rare earth ores have been achieved by high performance ion-interaction chromatography. Ores are decomposed by sulfuric acid and the rare earths are precipitated in a group as oxalates. Yttrium is then separated from the other rare earths on a C-18 bonded phase silica column modified with 1-octanesulfonate by linear concentration gradient elution for 20 min with 0.15 to 0.40M glycolic acid(pH 3.5). Yttrium elutes at about 10 min between samarium and neodymium, being separated selectively from all the rare earths as well as scandium, thorium and uranium. Post-column reaction detection and quantitation with Arsenazo III [2,7-bis(2-arsonophenylazo)-1,8-dihydroxynaphthalene-3,6-disulfonic acid] are carried out at 650 nm. Quantitative results are quoted for yttrium in sophisticated, synthetic rare earth mixtures, monazite and xenotime.     

Determination of scandium by atomic absorption

A comprehensive study has been made of the determination of scandium by atomic absorption. In addition to the instrumental variables such as flame-height, slitwidth and lamp current, a number of solution variables have been studied including the effect of anions (chloride, sulfate, nitrate, and fluoride), organic solvents, and other metals on the determination of scandium. Standard conditions have been established for the detection of minor amounts of scandium in a wide variety of materials including complex alloys of iron, nickel, aluminium, magnesium, and the rare earths.     

Raman spectroscopic study of the rare earth sesquisulfides

Raman spectra have been measured on carefully synthesized and characterized sesquisulfides of the rare earth ions plus yttrium and scandium. Six structure-types are represented. The Raman spectra are diagnostic of the structure-types. Raman line widths indicate structural disorder only in the defect gamma-type structure. High wavenumber bands shift with ionic radius of the rare earths and only slightly with cation coordination number.     

Chromatographic detection of scandium

Scandium was readily detected by paper chromatography using methyl acetate as the solvent and quinalizarin for the developer. The reddish-violet color formed with scandium resembled the colers obtained with thorium, titanium, zirconium and the rare earths, but the difference in R_F values gave definite separation of these elements. Positive chromatographs were obtained by using 0.01 ml of solution 0.005M respect to scandium.