仲辛基苯氧基乙酸从稀土中萃取分离钪及其机理

首次研究了一种新型萃取剂仲辛基苯氧基乙酸 (CA 12 )萃取钪的性能及其机理。通过研究平衡水相酸度、萃取剂浓度和温度对萃取平衡的影响 ,用斜率法和等摩尔系列法确定了CA 12萃取钪的机理 ,并求得了CA 12萃取钪的热力学函数 ,计算了平衡反应的浓度平衡常数及钪同其它稀土离子的分离系数 ,指出CA 12是一种从稀土 中分离钪的优良萃取剂     

仲辛基苯氧基乙酸从烯土中萃取分离钪及其机理

首次研究了一处新型萃取剂仲辛基苯氧基乙酸(CA-12)萃取钪的性能及其机理,通过研究平衡水相酸度,萃取剂浓度和浊度对萃取平衡的影响,用斜率法和等摩尔系法确定了CA-12萃取钪的机理,并求得CA-12萃取钪的热力学函数,计算了平衡反应的浓度平衡数学及钪同其它稀土离子的分离系数,指出CA-12是一种从稀土(III)中分离钪的优良萃取剂.     

冠醚萃取苦味酸钪与配合物的晶体结构研究

研究了苯并15冠5(B15C5)和二苯并18冠6(DB18C6)萃取苦味酸钪的萃取平衡。在pH2～3,用斜率法确定了两种萃合物的组成,并由此计算了它们的表观萃取平衡常数。通过苯并15冠5苦味酸钪配合物的合成、表征及晶体的结构测定,讨论了萃取机理。     

冠醚萃取苦叶酸钪与配合物的晶体结构研究

研究了苯并１５冠５（Ｂ１５Ｃ５）和二苯并１８冠６（ＤＢ１８Ｃ６）萃取苦味酸钪的萃取平衡。在ｐＨ２～３，用斜率法确定了两种萃合物的组成，并由此计算了它们的表观萃取平衡常数。通过苯并１５冠５苦味酸钪配合物的合成、表征及晶体的结构测定，讨论了萃取机理。     

石油亚砜萃取色谱法分离钪和稀土

提出以石油亚砜为固定相,硫氰酸铵和盐酸为流动相的萃取色谱法分离钪和稀土。研究了影响钪和稀土分离的条件,本体系中钪和钕的分离系数达到1.3×10~4。该方法可用于混合稀土中小量钪的分离,提取和分析。     

选择性萃取分离酸溶液中钪的试验与热力学研究

采用P507选择性萃取分离赤泥酸浸液中的钪。研究了溶液pH值、P507用量、A/O和萃取时间对钪萃取率和分离效果的影响,同时分析了此体系中钪萃取热力学及钪和铁的萃取分离动力学特征。结果表明:当溶液pH值为0.6,P507用量为8%,A/O为15和震荡时间为6 min时,钪萃取率可达99%。铁离子是影响钪萃取和分离的主要杂质离子,随着震荡时间从2 min提高至10 min,D_(Sc)可由48提高到1650,而D_(Fe)仅提高至3.1,此时钪和铁均未达到平衡。当反应时间为6 min时,钪对铁的分离系数最大,β_(Sc/Fe)可达到776,此体系中钪的萃取焓变为20.46 kJ·mol(-1)。     

阴离子树脂苯取富集-分光光度法测定煤矸石中痕量钪

研究了对乙酰基偶氮氯膦(CPApA)与钪(Ⅲ)的显色反应,在HNO3介质中,在Triton X-100存在下,CPApA与钪(Ⅲ)反应生成摩尔比为1:1的稳定配合物,该配合物可用717型阴离子树脂交换柱萃取富集,再通过树脂相光度法测定钪,由此建立了测定钪的新方法.吸附配合物树脂相的最大吸收波长为690 nm,表观摩尔吸光系数为9.56×105 L·mol-1·cm-1.钪的质量浓度在0～480μg/L范围内符合比耳定律.经阴离子树脂交换柱萃取富集后,钪的测定灵敏度可提高数倍,大多数常见离子不干扰测定.方法应用于煤矸石痕量钪的测定,结果满意.样品分析结果的相对标准偏差小于5%,加标回收率为96.0%～102.5%.     

伯胺N1923萃取色谱法分离硫酸介质中钪,铁,钛的研究

本文研究了Ｎ１９２３为固定相分离硫酸介质中钪、铁、钛的萃取色谱体系，流动相采用２ＭＨ２ＳＯ４－２ＭＨ２ＳＯ４＋Ｈ２Ｏ２－２ＭＨＣｌ三段淋洗能将三元素完全分离；又研究了Ｎ１９２３－ＴＢＰ二元固定相的分离情况，采用２ＭＨ２ＳＯ４＋Ｈ２Ｏ２－２ＭＨＣｌ二段淋洗，铁钛被同时淋出后与钪完全分离。钪回收率分别为１０７％和９８％。     

石油亚砜萃取分离稀土和钪

本文研究了稀土和钪在 PSO-HCl、PSO-HNO_3、PSO-NH_4SCN-HCl 体系中萃取行为、其中 PSO-NH_4SCN-HCl 体系的β_(Nd)~(Sc)高达5×10~3。应用于大量稀土中小量钪的分离和测定。     

氧化钪中微克量钍的萃取色谱分离——偶氮胂Ⅲ光度测定

钍和钪的分析化学性质十分相似,因此给氧化钪中钍的分析带来了困难。我们根据钪和钍在磷酸三丁酯-硝酸体系中的萃取特性,用萃取色谱法从大量钪中分离出微克量钍,然后用偶氮胂Ⅲ光度法进行测定。 (一)仪器和主要试剂QV-50分光光度计;氧化钪(光谱纯);硝酸钍和硝酸(分析纯);磷酸三丁酯     

Synergism in the extraction of scandium

Synergism in the extraction of scandium by a mixture of di-2-ethylhexyl phosphoric acid and a β-diketone has been studied. The nature of the extracted species has been investigated. The effect of temperature on extraction has been studied and synergism has been explained on the basis of thermodynamic parameters of the extraction process.     

Stereoselective catalytic tishchenko reduction of β-hydroxyketones using scandium triflate

A number of aliphatic and aromatic β-hydroxyketones were reduced to 1,3-diol monoesters by aldehydes in the presence of a catalytic amount of scandium triflate. Chiral substrates were reduced with high 1,3-anti diastereoselectivity.     

Cyanex 923从硫酸体系中萃取钪及其与P507和环烷酸的比较

稀土元素钪(Sc)在相关原料中含量低,伴生杂质元素多,回收困难。针对这一问题,本文系统对比了直链三烷基氧化膦(Cyanex 923)、2-乙基己基磷酸单-2-乙基己基酯(P507)、环烷酸在硫酸体系中对Sc的萃取、分离和反萃。Cyanex 923在高酸度下能完全萃取Sc,而环烷酸和P507则在低酸度下有较高萃取率。Cyanex 923分离Sc与锆(Zr)、钛(Ti)的最佳水相酸度为1 mol/L,分离系数分别为5. 6和10. 6。P507在水相H~+浓度为2 mol/L时对Sc/Zr、Sc/Ti有最大分离系数,分别是21和59. 7。虽然P507有更好的分离效果,但难以反萃。3种萃取剂中仅有Cyanex 923能被有效反萃,在反酸H+浓度为0. 4 mol/L时有最大反萃率。因此,Cyanex 923更适合从含Sc二次资源浸出液中分离回收Sc。     

ICP-AES手动扫描光电测定微量钪

用ICP -ABS手动扫描光电测定硫酸钛白母液中微量钪 ,考察了基体及硫酸的存在对钪发射强度的影响 ,并采用标准加入法扣除样品基体的影响。本法无需经过分离、富集等预处理 ,方法简便、快速。     

对氯偶氮氯膦光度法连续测定矿石中稀土总量与钪

在一定的条件下,对氯偶氮氯膦(CPA_pC)与等量的15种单一稀土所形成的络合物具有彼此相似的吸光度值。且该试剂也是钪的灵敏显色剂。据此分析特性,连续测定了矿石中稀土总量与钪,分析结果与标准数据基本相符。     

二溴水杨醛异烟酰腙的合成及其与钪的荧光反应研究

合成了新荧光试剂３，５－二溴水杨醛异烟酰腙（简称ＤＢＳＩＮ），研究了该试剂与钪的荧光反应，在ｐＨ４．７～５．５乙醇／水溶液中，试剂与钪所形成的荧光络合物的λｅｘ＝３３５．４ ｎｍ、λｅｍ＝５１０ｎｍ．提出了混合稀土氧化物中微量钪的测定法。     

Determination of scandium in wolframite and in the residues obtained after the extraction of tungsten

The separation of scandium from iron and manganese by extraction with TBP from hydrochloric acid was studied in detail and this method was applied to the estimation of scandium in wolframite and its residues. The method consists of the extraction of tungsten from the wolframite with sodium carbonate, dissolution of the residue in hydrochloric acid and preferential extraction of iron and scandium from hydrochloric acid, stripping of the scandium with 8 M hydrochloric acid and re-extraction of accompanying iron with fresh TBP, precipitation of scandium with ammonia in presence of ammonium chloride, and final purification of the scandium by TBP extraction.     

Direct dehydration polycondensation of lactic acid catalyzed by water‐stable Lewis acids

Poly(L ‐lactic acid) (PLLA) is generally produced by ring‐opening polymerization of (S,S)‐lactide, which is prepared from dehydration polycondensation of lactic acid and successive depolymerization. Results of this study show that scandium trifluoromethanesulfonate [Sc(OTf)₃] and scandium trifluoromethanesulfonimide [Sc(NTf₂)₃] are effective for one‐step dehydration polycondensation of L ‐lactic acid. Bulk polycondensation of L ‐lactic acid was carried out at 130–170 °C to give PLLA with M_n of 5.1 × 10⁴ to 7.3 × 10⁴ (yield 32–60%). The solution polycondensation was performed at 135 °C for 48 h to afford PLLA with M_n of 1.1 × 10⁴ with good yield (90%). In no case did ¹H NMR, specific optical rotation, or DSC measurement confirm racemizations. The catalyst was recovered easily by extraction with water and reused for polycondensation. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5247–5253, 2006     

Physicochemical study of the compounds in the three-component system Sc2O3-SeO2-H2O AT 100°C

The selenites of scandium are used as new materials in producing instrument and semi-conductor engineering. Like tellurites, they can also be applied as materials for making lasers. The process of producing scandium selenides by the reduction of the corresponding selenites has the advantage of taking place at relatively low temperatures and high rate. In this respect, it is necessary to command methods of obtaining high-purity selenites and to obtain data concerning their thermal stability. A physicochemical study of the system Sc₂O₃-SeO₂-H₂O was carried out at 100°C in order to find solutions to these problems. The possible compounds in the system at a given temperature were obtained. The compounds were identified by the Schreinemakers' method and also by chemical and X-ray phase analyses. The mechanism of thermal decomposition was determined by means of a derivatograph. This revised version was published online in July 2006 with corrections to the Cover Date.     

Marine Exopolysaccharide Complexed With Scandium Aimed as Theranostic Agents

(1) Background: Exopolysaccharide (EPS) derivatives, produced by Alteromonas infernus bacterium, showed anti-metastatic properties. They may represent a new class of ligands to be combined with theranostic radionuclides, such as ⁴⁷Sc/⁴⁴Sc. The goal of this work was to investigate the feasibility of such coupling. (2) Methods: EPSs, as well as heparin used as a drug reference, were characterized in terms of molar mass and dispersity using Asymmetrical Flow Field-Flow Fractionation coupled to Multi-Angle Light Scattering (AF4-MALS). The intrinsic viscosity of EPSs at different ionic strengths were measured in order to establish the conformation. To determine the stability constants of Sc with EPS and heparin, a Free-ion selective radiotracer extraction (FISRE) method has been used. (3) Results: AF4-MALS showed that radical depolymerization produces monodisperse EPSs, suitable for therapeutic use. EPS conformation exhibited a lower hydrodynamic volume for the highest ionic strengths. The resulting random-coiled conformation could affect the complexation with metal for high concentration. The LogK of Sc-EPS complexes have been determined and showing that they are comparable to the Sc-Hep. (4) Conclusions: EPSs are very promising to be coupled with the theranostic pair of scandium for Nuclear Medicine.