Determination of Dysprosium(III) Ion in Soil and Sediment Samples by an Original Potentiometric Dysprosium(III) Membrane Sensor

Abstract

A PVC membrane electrode for dysprosium(III) [Dy(III)] ions was constructed, having its basis on benzoxazoleguanidine (BG) as a suitable ionophore. The sensor presents a linear dynamic range of 1.0 × 10^?6–1.0 × 10^?1 M, with a Nernstian slope of 19.5 ± 0.4 mV decade^?1 and a detection limit of 4.7 × 10^?7 M. The response time is quick (less than 10 s). It can be used in the pH range of 3.3–8.4, and its duration is at least 2 mo without any considerable, noticeable potential divergence. The recommended sensor revealed comparatively good selectivity with respect to most alkali, alkaline earth, some transition, and heavy metal ions. It was successfully employed as an indicator electrode in the potentiometric titration of Dy(III) ions with EDTA. The membrane sensor also applied to the determination of concentration of Dy(III) ions in soil and sediment samples. Validation with certified reference materials (CRMs) was also carried out.     

Dysprosium(III) catalysis in organic synthesis

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基于与异乳清酸的配位反应及1,2-丙二醇增敏的铕、铽及镝的荧光分光光度测定

研究了9种有机溶剂对Eu3 、Tb3 、Dy3 三种稀土离子与异乳清酸的配位反应后所发射的特征荧光的强度,结果发现1,2-丙二醇的增敏效果最显著.在此基础上提出了荧光分光光度法测定上述3种稀土元素的方法,并对有机溶剂对荧光强度的增敏作用的机理作了探讨.试验的最佳条件为在pH 8.0的氨性缓冲介质中并含有40%(体积分数)1,2-丙二醇和7.0×10-4molL-1异乳清酸.试验结果Eu3 、Tb3 、Dy3 的激发波长均为300 nm,发射波长分别为612,544,574 nm,线性范围分别为0.60～8.00,0.000 5～3.00,0.20～7.00 mg·L-1;检出限分别为0.56,5.3×10-4,0.18 mg·L-1;用标准加入法做回收率试验,结果在95.6%～109.3%之间.     

Spectrophotometry Determination of Ciprofloxacin in Serum Using Iron(III) Ion as Chromogenic Agent

ABSTRACT

An analytical procedure for the determination of ciprofloxacin in serum without previous extraction has been developed. The determination was carried out using iron(III) nitrate as chromogenic agent, with the addition of sodium dodecylsulfate, at pH = 3.0. Absorbance was measured at 430 nm. The range of linearity was between 0.5 – 20.0 μg/mL with a detection limit 0.2 μg/mL.     

Spectrophotometric Determination of Dioxovanadium (V) Ion Using Some Halogen Derivatives of Phenylazo-Chromotropic Acid

A comparative study of the reaction of o-chloro-, m-chloro-, p-chloro-, p-bromo- and p-iodophenylazo-chromotropic acids with dioxovanadium (V) ion have shown that 1:1 and 1:2 violet water soluble complexes were formed at pH 4.5. The p-halogeno-derivatives were found to be very suitable reagents for spectrophotometric determination of VO⁺₂ up to 8 ppm. The application of these dyes as indicators in the spectrophotometric titration of VO⁺₂ with EDTA and the interference of a various cations and anions were reported.     

The Solid State Electrochemistry of Dysprosium(III) Hexacyanoferrate(II)

A new electroactive polynuclear inorganic compound of rare earth metal hexacyanoferrate, dysprosium hexacyanoferrate (DyHCF), was prepared chemically and characterized using techniques of FTIR spectroscopy, thermogravimetric analysis (TGA), UV‐vis spectrometry and X‐ray photoelectron spectroscopy (XPS) etc. The cyclic voltammetric behavior of DyHCF mechanically attached to the surface of graphite electrode was well defined and exhibited a pair of redox peaks with the formal potential of 217 mV (vs. SCE) at a scan rate of 100 mV/s in 0.2 M NaCl solution and the redox peak currents increased linearly with the square root of the scan rates.     

Flow Injection Chemiluminescence Determination of Pipemidic Acid Using On-Line Electrogenerated Cobalt(III) as Oxidant

 A novel flow injection chemiluminescence (CL) system for the determinati on of pipemidic acid is described. It is based on the direct CL reaction of pipemidic acid and Co(III) in acid medium. The unstable Co(III) was on-line electrogenerated by constant current electrolysis. The CL intensity was linear with pipemidic acid concentration in the range of 0.01∼100 μg/ml, the determination limit was 3.3×10⁻⁹ g/mL. The whole process could be complete d in 1 min with a relative standard deviation of 3.2%. The proposed method is suitable for automatic and continuous analysis and has been applied successfully to the analysis of pipemidic acid in a pharmaceutical preparation. Received November 22, 1999. Revision March 24, 2000.     

Highly Axial Magnetic Anisotropy in a N3O5 Dysprosium(III) Coordination Environment Generated by a Merocyanine Ligand

A spiropyran‐based switchable ligand isomerizes upon reaction with lanthanide(III) precursors to generate complexes with an unusual N₃O₅ coordination sphere. The air‐stable dysprosium(III) complex shows a hysteresis loop at 2 K and a very strong axial magnetic anisotropy generated by the merocyanine phenolate donor.     

State and Stability of Erbium(III) and Dysprosium(III) Complexes of Octaphenyltetraazaporphine in Proton-Donor Media

The acid-base interaction of chloro(octaphenyltetraazaporphinato)erbium(III), (acetylacetonato)(octaphenyltetraazaporphinato)erbium(III), and (acetylacetonato)(octaphenyltetraazaporphinato)dysprosium(III) in AcOH and in AcOH-benzene and AcOH-H₂SO₄ systems involves one meso-nitrogen atom of the complexes; the stability constants of the resulting acid forms were estimated. The solvoprotolytic dissociation of the complexes in the AcOH-H₂SO₄ system was studied, its kinetic parameters were determined, and some suggestions as to the dissociation mechanism were made.     

Solvent-Induced Single-Crystal-to-Single-Crystal Transformation in Multifunctional Chiral Dysprosium(III) Compounds

Two new enantiomeric ionic chiral dysprosium(III) compounds were designed and synthesized. These compounds show simultaneously the optical activity, ferroelectric effects, nonlinear-optical effects, and slow magnetic relaxation behavior. More interestingly, these compounds exhibit reversible single-crystal-to-single-crystal transformations associated with the release or absorption of solvent molecules. The structure transformations are accompanied by distinct changes in the physical properties.     

高效液相色谱法分析精对苯二甲酸中的微量杂质

应用高效液相色谱法,采用阴离子交换键合固定相,以磷酸盐缓冲溶液为流动相,ＵＶ２５４ｎｍ检测,外标法定量,同时测定了精对苯二甲酸（ＰＴＡ）中的主要杂质４－羧基苯甲醛（４－ＣＢＡ）和对甲基苯甲酸（ｐ－ＴＯＬ）的含量,４－ＣＢＡ和ｐ－ＴＯＬ的回收率分别为９８．３％～１０５．０％和９６．０％～１０３．８％,变异系数分别小于１．７％和３．３％。方法快速、准确,用于实际样品分析可得到满意的结果。     

以对苯二甲酸为手臂连接剂的大肠杆菌DNA传感器

将空心球状CdS超声分散于聚乙烯醇(PVA)溶液中, 得到均匀的CdS-PVA复合材料分散液. 取适量分散液滴涂于玻碳电极表面, 晾干得到CdS-PVA修饰电极. 以对苯二甲酸为手臂连接剂, 在CdS-PVA膜上共价固定大肠杆菌特定寡聚核苷酸序列, 构建了一种新型的DNA传感器. 采用电化学阻抗法考察了该传感器的分析性能, 结果表明该传感器能有效区分互补序列、 单碱基错配序列、 三碱基错配序列和完全错配序列, 可在1.0×10^-12～1.0×10^-7 mol/L范围内对大肠杆菌目标序列进行定量分析, 检出限为1.3×10^-13 mol/L. 将该传感器应用于大肠杆菌实际样品的检测, 结果令人满意.     

Chromium(III) Ion Selective Electrode Based on Oxalic Acid Bis(Cyclohexylidene Hydrazide)

A poly(vinyl chloride) membrane sensor based on oxalic acid bis (cyclohexylidene hydrazide) as membrane carrier was prepared and investigated as a Cr(III)‐selective electrode. The electrode reveals a Nernstian behavior (slope 19.8±0.4 mV decade^?1) over a wide Cr(III) ion concentration range 1.0×10^?7–1.0×10^?2 mol dm^?3 with a very low limit of detection (i.e., down to 6.3×10^?8 mol dm^?3). The potentiometric response of the sensor is independent of the pH of the test solution in the pH range 1.7–6.5. The electrode possesses advantage of very fast response, relatively long lifetime and especially good selectivity to wide variety of other cations. The sensor was used as an indicator electrode, in the potentiometric titration of chromium ion and in the determination of Cr(III) in waste water and alloy samples.     

A Study of Magnetic Relaxation in Dysprosium(III) Single-Molecule Magnets

Although the development of single-molecule magnets (SMMs) is rapid, there are only two families of high energy barrier (U_eff) dysprosium(III) SMMs known so far: the cyclopentadienyl (Cp) family with a sandwich structure and the pentagonal-bipyramidal (PB) family with D_5h symmetry. These high-barrier SMMs, which usually possess U_eff>500 cm⁻¹ allow the separate study of the four magnetic relaxation paths, namely, direct, quantum tunnelling, Raman and Orbach processes, in detail. Whereas the first family is chemically more challenging to modify the Cp rings, it is shown herein that the latter family, with the common formulae [DyX¹X²(L_eq)₅]⁺, such as X¹/X²=⁻OCMe₃, ⁻OSiMe₃, ⁻OPh, Cl⁻ or Br⁻; L_eq=THF/pyridine/4-methylpyridine, can be readily fine-tuned with a range of axial and equatorial ligands by simple substitution reactions. This allows unambiguous confirmation that the U_eff mainly depends on the identity of X¹ and X², rather than on L_eq. More importantly, the fitted parameters are barrier dependent. If X¹ is an O donor and X² is a halide, 500<U_eff<600 cm⁻¹, log τ_0avg (s)=−10.66, log C_avg (s⁻¹ K⁻ⁿ)= −5.05, n_avg=4.1 and T_H=9 K (in which τ₀ is the pre-exponential factor for the Orbach relaxation process, C and n are parameters used to describe Raman relaxation, and T_H is the highest temperature at which magnetic hysteresis is observed). For cases in which both X¹ and X² are O donors, 900<U_eff<1300 cm⁻¹, log τ_0avg (s)=−11.63, log C_avg (s⁻¹ K⁻ⁿ)= −6.03, n_avg=4.1 and 18<T_H<25 K. Based on these results, it can be further concluded that U_eff not only has a linear correlation to the axial Dy−X bond lengths, but also to T_H for these PB SMMs. This represents the first systematic study of a family of lanthanide SMMs and derives the first magneto-structural correlation in Dy SMMs.     

Synthesis,Structure, Luminescent and Thermal Properties of Ytterbium(III) and Dysprosium(III) Complexes with 5‐Sulfoisophthalic Acid Sodium Salt

Two rare earth metal‐organic framework compounds [Ybsip(H₂O)₅] · 3H₂O ( 1 ) and [Dysip(H₂O)₄] ( 2 ) (NaH₂sip: 5‐sulfoisophthalic acid sodium salt) were synthesized hydrothermally, and characterized by single‐crystal X‐ray diffraction, elemental analysis, and FT‐IR spectroscopy. In complex 1 , each Yb^III atom is nine‐coordinate with a distorted monocapped tetragonal prismatic arrangement. Two carboxylate groups of each sip^3– molecule adopt the same μ₁‐η¹:η¹ chelating coordination model connecting two Yb^III atoms. The oxygen atoms of the sulfonate group do not participate in coordination with Yb^III. The whole sip^3– molecule acts as a μ₂ bridge to form an one‐dimensional (1D) chain structure. The 1D chains are linked by hydrogen bonding to generate two‐dimensional layers, and are further combined together to form a three‐dimensional structure. In complex 2 , the Dy^III atom is nine‐coordinate with a distorted monocapped tetragonal antiprismatic arrangement. In each sip^3– anion, two carboxylate groups take the same μ₁‐η¹:η¹ chelating coordination mode, only an oxygen atom of sulfonate group bond to Dy^III ion. The whole ligand sip^3– acts as a μ₃ bridge linking three different Dy^III ions to generate a wave‐like two‐dimensional network with (6,3) topological structure. The two‐dimensional networks are further linked by O–H ··· O hydrogen bonds to form a three‐dimensional structure. The thermal and luminescent properties of both complexes are investigated.     

Luminescence studies of diopside doped with various concentrations of Dysprosium (III)

Research on Chemical Intermediates - Diopside doped with various concentration (0.5, 1.0, 1.5, 2.0 and 2.5&nbsp;mol%) of Dysprosium were&nbsp;prepared using solid-state reaction technique....     

Determination of Aluminium by Potentiometry Using Carbon Paste Ion Selective Electrode Based on N,N'-bis(salicylidene)-1,3-Propanediamine Ligand

Journal of Analytical Chemistry - A new Al3+ carbon paste ion selective electrode based on N,N'-bis(salicylidene)-1,3-propanediamine (SB-Salpr) was prepared for the quantification of trace...     

Kinetics and Mechanisms of Reactions of some complexes of Chromium(III). Formation of Oxalatobis(biguanide) chromium(III) Ion from Diaquobis(biguanide) chromium(III) Ion and its Dissociation in Acid Medium

The kinetics of formation of oxalatobis(biguanide)chromium(III) ion from diaquobis(biguanide)chromium(III) ion and oxalate has been studied in aqueous solution (pH ca. 3–4). The results indicate ion-pair formation between the reacting species followed by reaction by an essentially dissociative mechanism (S_N1IP). The kinetics of dissociation of the oxalatobis(biguanide)chromium(III) ion in acid medium has also been studied. The reactions involved are the loss of the two biguanide ligands in stages and by proper choice of acid concentrations and temperature the rates of the two steps could be followed separately. The results indicate S_N2CA mechanism.