稀土离子的高效毛细管电泳分离和测定

以咪唑为背影为电解质，以乳酸作为络合剂，采用毛细管离子电泳间接紫外法，研究了分离与测定稀土离子的方法，考察了背景电解质酸度、络合剂浓度，背景电解质共存离子的浓度，分离电压对稀土离子的影响。     

背景电解质的组成对毛细管电泳分离和测定稀土离子的影响

研究了以咪唑为间接紫外共存离子,以乳酸或α－羟基异丁酸为络合剂,对１４个稀土离子进行毛细管电泳分离测定的方法。考察了背景电解质ｐＨ值、不同络合剂及其浓度、调节ｐＨ值所用的酸对稀土离子分离及定量测定的影响。选择了３种分离稀土离子的体系测定实际样品中各稀土含量。实验结果表明：以Ｔｂ作内标,以各离子相对于Ｔｂ的峰面积定量,可抵消进样不准确引起的误差。测定结果与ＩＣＰ法测定结果一致。     

高效毛细管电泳测定混合氯化稀土中的稀土元素

研究了在以含有紫外吸收的咪唑为背影电解质和以α－羟基异丁酸为络合剂的缓冲液体系中，用毛细管电泳间接外法检测和然土离子的方法，讨论了各操作条件对稀土离子分离泊影响。     

高效毛细管区带电泳检测稀土元素

本文使用背景电解质为含有吸收作用的肌酸酐和作为配合对离子的羟基异丁酸，肜高效毛区带电泳（ＣＺＥ）间接紫外光度法测定稀土元素。探讨了背景电解质酸度，吸光共存离子和配合对离子浓度对稀土电泳分离的影响；提出用背景电解质预，沉积法克服毛细管壁的强烈吸附干扰。９种稀土元素混合物１１ｍｉｎ内完成分离检测。应用内标法对稀土钢样中单个稀土含进行了定量分析。     

毛细管电泳柱上络合分离、间接紫外检测重金属离子

采用弱络合剂乙醇酸,柱上络合,间接紫外检测毛细管区带电泳(CZE)技术对重金属离子Ba2+、Cr3+、Cd2+、Pb2+及可能存在的干扰离子进行了分离研究。通过对背景电解质种类和浓度、缓冲液pH、有机添加剂等的优化,确定了最佳分离体系为含12 mmol/L络合剂乙醇酸的10 mmol/L吡啶溶液作为背景电解质(pH 4.0)。在电压15 kV,压差进样68.95 kPa.s,260 nm间接紫外检测条件下,采用50 cm(45.5 cm)×50μm(I.D.)石英毛细管,重复性实验(n=9):迁移时间RSD≤1.37%,峰高RSD≤1.70%,峰面积RSD≤3.55%;Pb2+、Ba2+和Cd3+的检出限(S/N=3)为0.2 mg/L,Cr3+的检出限为0.08 mg/L;在检出限至10 mg/L范围内,各离子的浓度与峰面积线性相关系数好于0.998。该方法并应用于实际样品的分析。     

人血白蛋白制品中超痕量铝的测定

建立了浊点萃取石墨炉原子吸收光谱法测定人血白蛋白样品中超痕量铝的新方法。探讨了溶液酸度、络合剂的种类及浓度、非离子表面活性剂的浓度、平衡时间及温度等因素对浊点萃取过程的影响。以1-(2-吡啶偶氮)-2-萘酚为络合剂,Triton X-114为非离子表面活性剂,浊点萃取分离富集10mL样品溶液,Al(Ⅲ)的富集倍数为34.8,在最佳工作条件下,铝的检出限为0.06μg/L;样品测定的相对标准偏差(n=7)为3.6%,加标回收率95.6%~98.4%。方法适合人血白蛋白样品中超痕量铝的分析测定。     

采用毛细管电泳电堆集富集技术分离与测定雪样中的痕量阳离子

以咪唑为背景电解质,以α－羟基异丁酸和１８－冠醚－６为络合剂,采用毛细管离子电泳间接紫外法,研究了发样中痕量ＮＨ４＾＋、Ｋ＾＋、Ｃａ＾＋、Ｍｇ＾２＋分离与测定的方法。通过向缓冲液中加入甲醇,使Ｃａ＾２＋、Ｎａ＾＋迁移顺序发生反转,有利于在Ｃａ＾２＋的浓度较高时少量Ｎａ＾＋的测定。采用电堆集富集技术,各离子的检测限达１×１０＾－７ｍｏｌ／Ｌ。以Ｌｉ＾＋作为内标,采用标准加入法对地样中的痕量阳离子进行     

高效毛细管电泳间接紫外检测血浆中钾、钙、镁

用高效毛细管电泳法,在pH 5.5的缓冲介质中用酒石酸作为络合剂,使血浆中钾、钠、钙、镁4种阳离子达到很好分离,用咪唑作为背景试剂进行了紫外检测.对电泳分离及紫外检测的各分析条件(包括背景缓冲溶液的pH值,咪唑溶液的浓度及酒石酸溶液的浓度等)作了试验并予以优化,上述4种离子的相互分离在4.5 min内顺利完成.文中给出了K 、Ca 、Mg2 的线性回归方程,其相关系数在0.998 4～0.999 4之间,证明了在各离子的峰面积与其浓度之间呈线性关系,3种离子的检出限(S/N=3)依次为0.20,0.12,0.06 mg·L-1.用迁移时间检测和用峰面积检测所得的RSD值(n=6)依次小于0.76%和2.83%.由于钠离子的吸收峰与系统峰重叠,钠的测定无法进行.回收率试验的结果在95.3%至104.2%.     

毛细管区带电泳中钴、镍、锌、锰等金属离子的络合富集

提出了CZE络合富集的基本方法。通过络合作用使金属离子在样品区带和背景电解质中具有不同迁移速度而实现富集。以金属离子Co^2 、Zn^2 、Mn^2 和Ni^2 为溶质，4-(2-吡啶偶氮)间苯二酚(PAR)和EDTA为络合剂进行实验研究，探讨了柱容量、样品浓度、络合剂种类及进样方式等参数对富集的影响。在不超出柱容量的情况下，峰高随着进样时间的增加而增大。采用pH8．40、6．25mmol／L硼酸盐分离不同浓度Co^2 、Ni^2 ，进样量可增加约100倍，检测灵敏度增加40倍。     

用可编程序电子计算器计算溶解度

考虑络合效应,须计算共同离子时配位体难溶电解质的溶解度,其关键是如何计算平衡时配位体的浓度。在一般分析化学教材中均假定加入的络合剂浓度,就是平衡时配位体的浓度,有人提出,对于 MA_n 型难溶电解质,平衡时配位体的浓度也可用下式计算:     

Separation of yttrium from heavy lanthanide by CA-100 using the complexing agent

The selective extraction of yttrium from heavy lanthanide by liquid-liquid extraction using CA-100 in the presence of the complexing agent, such as EDTA, DTPA, and HEDTA was investigated. The extraction of heavy lanthanide in the present of the complexing agent was suppressed when compared to that of Y because of the masking effect, but the selective extraction of Y was enhanced. All complexing agents formed 1:1 complex with rare earth elements (RE), and only free rare earth ions could take part in the extraction. The condition for separation was obtained by exploring the effects of the complexing agent concentration, the extractant concentration, pH and the equilibration time on the extraction of the heavy rare earth elements.     

PERVAPORATION SEPARATION OF WATER-ACETIC ACID MIXTURES THROUGH AN-co-AA MEMBRANES TREATED WITH RARE EARTH METAL IONS

Pervaporation separation of water-acetic acid mixtures through Poly (AN-co-AA)membranes and rare earth metal ions treated Poly(AN-co-AA)membranes was investigatedfor the first time. The results showed that the treatment with rare earth metal ions couldgreatly improve the characteristics of the separation of water-acetic acid mixtures.     

离子色谱法分析金属离子的研究进展

综述了离子色谱法(IC)分析金属离子的研究进展,对目前应用于分析金属离子的阳离子交换IC、阴离子交换IC和螯合离子色谱进行了评述。阳离子交换IC是IC分析金属离子的主要形式,固定相为强酸(磺酸)型阳离子交换剂和弱酸(羧酸)型阳离子交换剂,结合适当的检测方法,阳离子交换IC可以测定碱金属、碱土金属、过渡金属、稀土离子、铵离子及低相对分子质量的有机胺类分子等。阴离子交换IC可以分析碱土金属、过渡金属、稀土离子等,对金属离子的分析具有更好的选择性,并可以实现金属离子和无机阴离子的同时测定。螯合离子色谱可以对复杂基体中的痕量金属离子进行测定。引用文献125篇。     

Separation of metal ions by capillary electrophoresis with a complexing electrolyte

Excellent separations of metal ions can be obtained very quickly by capillary electrophoresis provided a weak completing reagent is incorporated into the electrolyte to alter the effective mobilities of the sample ions. Indirect photometric detection is possible by also adding a UV-sensitive ion to the electrolyte. Separations are described using phthalate, tartrate, lactate or hydroxyisobutyrate as the complexing reagent. A separation of twenty-seven metal ions was achieved in only 6 min using a lactate system. A mechanism for the separation of lanthanides is proposed for the hydroxyisobutyrate system.     

环烷酸类载体液膜体系对金属离子传输机理的研究

本文先在大块液膜体系中以环已烷甲酸为载体,通过正交设计,系统地研究了各种因素对希土离子输送作用的影响规律。比较了相同条件下RE~(3+)(希土)同Na~+,NH_4~+、Ca~(2+)和Fe~(3+)等离子的输送作用。发现在适当条件下,无皂化的羧酸载体对RE~(3+)离子具有良好的输送效果,同时证实,羧酸输送RE~(3+)离子是通过三个H~+离子与一个RE~(3+)离子的交换,而当载体皂化时,皂化的载体直接与接收相H~+离子发生交换,从而降低了羧酸对RE~(3+)离子的输送和分离效果。 在大块液膜研究的基础上,建立了一个以无皂化的环烷酸为载体的乳状液膜体系,从模拟离子矿的硫酸铵浸出液中萃取希土,通过正交试验确定了最优的液膜萃取条件,希土萃取率达96％以上,富集度30～40倍。     

Separation of metal ions by capillary electrophoresis

A number of experimental parameters have been optimized for the separation of 26 metal ions, including alkali, alkaline earth, transition and lanthanide metal ions. Experimental parameters that were evaluated included nature of indirect-detection reagent, pH of electrolyte, concentration of complexing agent and nature of the surface of the capillary; unbonded and C₁ and C₁₈ bonded phases were studied. In addition the effect of internal diameter on linearity and signal-to-noise ratio was examined, and separation efficiency was determined for a variety of experimental conditions. Detection limits (signal-to-noise RATIO = 3) were ca. 1 μg/ml for the lanthanides, ca. 0.6 μg/ml for transition and alkaline earth ions and ca. 0.1–0.8 μg/ml for alkali metal ions. The average relative standard deviations of were 3.7, 5.1 and 2.5% on unbonded, C₁ and C₁₈ capillaries, respectively. Whereas conventional regression analysis suggested that the calibration curves were linear over the range of 1·10⁻⁵ to 4·10⁻⁴ mol/l, sensitivity plots showed that the results were actually linear to within 6% only over the range of 2.5·10⁻⁵ to 4·10⁻⁴ mol/l.     

Ion-exchange thin-layer chromatography of metal lons in organic solvent — Hydrochloric acid — Complexing agent media

Summary Thin-layers of strongly basic or strongly acidic ionexchange resins (Dowex 1 or Dowex 50), mixed with a plain cellulose, Avicel SF, have been used to investigate the chromatographic behaviour of 40 metal ions in acetic acid — hydrochloric acid — complexing agent media. The CIESE (combined ion-exchange-solvent extraction) effect, proposed by Korkisch, is noticed for scandium and thorium in the anion-exchange system involving trioctylphosphine oxide (TOPO) as the complexing agent, the system providing a basis on the specific separation of both elements. In the cation-exchange system involving TOPO, the metal ions are distributed chromatographically, so that the system allows multicomponent separations to be carried out. The system also reveals the CIESE effect for zirconium and hafnium.     

Separating Behaviors of Heavier Rare Earth Metal Ions in Centrifugal Partition Chromatography with Di(2-Ethylhexyl) Phosphoric Acid

Abstract

The separating behaviors of SmCl₃, EuCl₃, GdCl₃, TbCl₃, DyCl₃, HoCl₃, ErCl₃, TmCl₃, YbCl₃, and LuCl₃ in Centrifugal Partition Chromatography with the stationary phase containing a separator, Di(2-ethylhexyl) phosphoric acid (D2EHPA), are examined. The separation trends of these heavier rare earth metal ions were found to be almost as expected from the observations reported for the lighter rare earth metal ions. And the separator is also useful for mutual separation of these heavier rare earth metal ions.     

Separation and direct UV detection of complexed lanthanides,thorium and uranyl ions with 2-thenoyltrifluoroacetone by using capillary zone electrophoresis

Separation and detection of lanthanides, thorium and uranyl ions by capillary zone electrophoresis in the presence of 2-thenoyltrifluoroacetone (HTTA) as UV-absorbing complexing agent were investigated. The separation of positively charged complexes is partially improved by using a competing ligand in buffer with HTTA for metal ions. When 2-hydroxyisobutyric acid (HIBA) is used as competing ligand, complete separation of thorium, uranyl and lanthanides ions were observed. Some separation parameters such as pH value, the concentration of carrier electrolyte, applied voltage, the concentration of ligand in buffer and the temperature were also optimized. Under the selected conditions, the complete separation of thorium and uranyl from each other and from lanthanides was accomplished in only 12 min using 1 mmol/L HTTA, 50 mmol/L HIBA, 5 mmol/L NaNO₃, 5 % methanol with a pH 5.2 at a capillary temperature of 25 °C. Direct photometric detection at 210 nm using a voltage of 25 kV and an electrokinetic injection (100 mm for 6 s) were used.