全固态复合式雷尼替丁电极的研究

制备了以脲醛树脂、KCl粉末、Ag/ Ag Cl丝为材料的 Ag/ Ag Cl固体电极 ,然后以此固体电极分别作为内外参比电极、以含四苯硼酸雷尼替丁离子对缔合物的 PVC膜作为敏感元件 ,组装成一种全固态复合式雷尼替丁电极 ,并详细研究了其性能。结果表明该电极具有良好的稳定性 ,其 Nernst响应范围为 5× 1 0 - 4～ 1× 1 0 - 1 mol/ L,斜率为 58.7m V/pc,检测下限为 2 .5× 1 0 - 4 mol/ L,使用寿命不少于 6个月 ,能用于盐酸雷尼替丁制剂的含量测定。     

Electroanalytical Studies on Cobalt(II) Ion‐Selective Sensor of Polymeric Membrane Electrode and Coated Graphite Electrode Based on N2O2 Salen Ligands

Poly(vinyl chloride)‐based membranes of salen ligands, 2‐((E)‐((1R,2S)‐2‐((E)‐5‐tert‐butyl‐2‐hydroxybenzylideneamino)cyclohexylimino)methyl)‐4‐tert‐butyl phenol (S₁) and 2‐((E)‐((1R,2S)‐2‐((E)‐3,5‐di‐tert‐butyl‐2‐hydroxybenzylideneamino)cyclohexylimino)methyl)‐4,6‐di‐tert‐butylphenol (S₂) were fabricated and explored as cobalt(II) selective electrodes. The performance of the polymeric membrane electrode (PME) and coated graphite electrode (CGE) were compared and it was observed that CGE showed a wide working concentration range of 1.1×10^?8 to 1.0×10^?1 mol L^?1 with a limit of detection of 7.0×10^?9 mol L^?1 exhibiting the Nernstian slope 29.6 mV/decade of activity in the pH range 3.0–9.0. It was used for the determination of cobalt(II) ions in water, soil, beer, pharmaceutical samples and medicinal plants and would be used as an indicator electrode in potentiometric titration with EDTA.     

牛磺酸双核铜络合物为载体的高选择性硫氰酸根离子电极的研究

本文报道了一种以牛磺酸双核铜络合物为中性载体的硫氰酸根PVC膜电极。该电极对硫氰酸根有良好的电位响应并呈现出anti-Hofmeister行为,其选择性顺序SCN^->I^->ClO₄^->Sal^->NO₃^-> NO₂^-> Br^- > Cl^- > SO₃^-> SO₄ ^2-。在20℃ pH 5.0的磷酸缓冲溶液中,其线性范围为1.0´10 ^-1~ 1.0´10^-6mol×L-1,检测线为8.0×10 ^-7mol•L^-1,斜率为 -56.5 mV/pcSCN^-。紫外、红外和交流阻抗研究表明电极的高选择性与载体的立体结构和分析物与中心金属离子的作用相关。将该电极用于废水和人体尿液中硫氰酸根的测定,获得了较满意的结果。     

铂电极上醋酸-醋酐溶液中Mn(III)/Mn(II)电对研究

平衡电极电势实验确定了25 ℃, 1.5 mol•L－1醋酸钾＋醋酸-醋酐(3:1体积比)溶液中Mn(III)/Mn(II)的条件电极电势为0.719 V（vs SCE）;采用电势扫描和旋转圆盘电极技术研究了醋酸-醋酐溶液中铂电极上Mn(III)/Mn(II)电对的阳极氧化动力学. 结果表明:Mn(II)阳极氧化成Mn(III)的电极反应控制步骤属电荷传递过程, 阳极传递系数β=0.347,交换电流密度i0=5.84×10－6 A•cm－2,阳极标准反应速率常数ka=1.35×10－8 m•s－1, Mn(II)和OAc－的反应级数均为一级.     

聚乙烯醇缩丁醛膜涂丝酶电极构造方法的研究

本文以三月桂胺为中性载体制成聚乙烯醇缩丁醛膜涂丝pH电极,再以该pH电极为换能器,采用三种共价交联固定化酶方法制成涂丝乙酰胆碱酯酶电极。该酶电极能用于测定0.1～10mmol/L浓度范围内的乙酰胆碱,响应时间在3～6min之内,寿命可达两个多月。     

The Potential Response Of Copper(Ii) Sulfide Ion Selective Electrode To Hg(Ii) Ions In Aqueous Solution

Abstract

The application of a cupric ion-selective electrode with a membrane of mixed Ag₂S-CuS to measure the activity of Hg(II) is presented. The linear electrode response curve which covers near three decades, from 10^?5 to 10^?2 mol dm^?3, of mercuric concentration range was obtained, under background of acetate buffer.     

A Novel Modified Carbon Paste Electrode for Potentiometric Determination of Mercury(II) Ion

A new modified carbon paste electrode (CPE) based on a recently synthesized ligand of Ethyl‐2‐(benzoylamino)‐3‐(2‐hydroxy‐4‐methoxyphenyl)‐2‐propenoate (EBHMP) as a suitable carrier for Hg²⁺ ion was described. The electrode exhibit a super Nernstian slope of 48.5±1.0 mV per decade for Hg²⁺ ion over a wide concentration range from 3.0×10^?7–3.1×10^?2 M. The lower detection limits are 1.0×10^?7 M Hg²⁺. The electrode has a fast response time (ca. 5 s), a satisfactory reproducibility and relatively long life time. The proposed sensor shows a fairly good selectivity toward Hg²⁺ ion in comparison to other common cations. The potentiometric responses are independent of the pH of the test solution in the pH range 1.0–4.0. The proposed electrode was used as an indicator electrode in potentiometric titration of mercuric ion with standard solution of EDTA. The direct determination of mercury in spiked wastewater and an amalgam sample gave results that compare favorably with those obtained by the cold vapor atomic absorption spectrometric method.     

Highly Selective Perchlorate Membrane Electrode Based on Cobalt(III) Schiff Base as a Neutral Carrier

A highly selective poly(vinyl chloride) (PVC) membrane electrode based on Co(III)-Schiff base [Co(5-NO2- Salen)(PBu3)]ClO4•H2O (where 5-NO2-SalenH＝bis(5-nitrosalycilaldehyde)ethylenediamine) as a new carrier for construction of perchlorate-selective electrode by incorporating the membrane ingredients on the surface of a graphite electrodes has been reported. The proposed electrode possesses a very wide Nernestian potential linear range to perchlorate from 1.0×10－6 to 5.0×10－1 mol•L－1 with a slope of (59.4±0.9) mV per decade of perchlorate concentration with a low detection limit of 5.0×10－7 mol•L－1 and good perchlorate selectivity over the wide variety of other anions. The developed electrode has an especially fast response (＜5 s) and a wide pH independent range (3.0—12.0) in comparison with recent reported electrodes and can be used for at least 2 months without any considerable divergence in their potential response. This electrode was used for the determination of perchlorate in river water, drinking water, sludgy water and human urine with satisfactory results without complicated and time consuming pretreatment.     

The 4‐(Dimethylamino) benzaldehyde‐4‐ethylthiosemicarbazone as Ionophore for Mercury(II) Solid State Selective Electrode

Hg(II) has formed a soluble complex with 4‐(dimethylamino) benzaldehyde‐4‐ethylthiosemicarbazone (DMABET) in methanol with a molar ratio of mercury(II):DMABET of 1 : 4. The formation constant (K_f) and Gibbs free energy (?G) of the complex showed that the formation of the complex was favorable. The DMABET was investigated as ionophore for Hg(II)‐ion selective electrode (ISE). At optimum pH 1–5 the proposed Hg(II)‐ISE showed an almost Nernstian slope at 27.8±1 mV, with linear regression coefficient, R²=0.995 and a detection limit of 5×10^?6 M. There was no serious interference from silver(I) with selectivity coefficient 5.69×10^?3. The electrode life span was more than 3 months. It has been applied for real water sample analysis and the results were in good agreement with the standard method.     

Thermal Studies of New Lead(II) Coated‐Wire Membrane Electrodes

Five plastic membrane Pb²⁺‐selective electrodes were prepared based on 1,4‐bis(N‐tosyl‐o‐aminophenoxy)butane I , 1,4‐bis(N‐allyl‐N‐tosyl‐o‐aminophenoxy)butane II , 1,4‐bis(N‐benzyl‐N‐tosyl‐o‐aminophenoxy)butane III , 1,4‐bis[N‐(o‐allyloxybenzyl)‐N‐tosyl‐o‐aminophenoxy]butane IV , and 1,4‐bis(N‐octyl‐N‐tosyl‐o‐aminophenoxy)butane V as neutral carriers. The electrodes exhibited nearly Nernstian responses over the concentration ranges, 2.5×10^?4–4.0×10^?2, 2.5×10^?5–4.0×10^?2, 7.9×10^?5–4.0×10^?2, 2.2×10^?5–4.0×10^?2, and 1.9×10^?4–4.0×10^?2 M for electrodes composed with the ionophores I–V , respectively. All electrodes showed pH range of about 4.0 to 11.5 and working temperature range of 22 to 70 °C with isothermal temperature coefficients of 1.19×10^?3, 1.16×10^?3, 1.16×10^?3, 1.00×10^?3 , and 1.32×10^?3 V/°C for electrodes I–V respectively.     

Highly Selective and Sensitive Tin(II) Membrane Electrode Based on a New Synthesized Schiff's Base

Studies on complex formation of tris(3‐(2‐hydroxybenzophenone)propyl)amine (THPA) with a number of metal ions in acetonitrile solution revealed the occurrence of a selective 1 : 1 complexation of the proposed ligand with Sn²⁺ ion. Consequently, THPA was used as a suitable neutral ionophore for the preparation of a polymeric membrane‐selective electrode. The electrode exhibits a Nernstian behavior with a slope of 29.4±0.3 mV per decade and a detection limit of 2.0×10^?7 M. It also showed a good selectivity for Sn²⁺ ions in comparison with some of group A and B metal ions over a wide concentration range of 5.0×10^?7–1.0×10^?1 M. Improved selectivity was achieved compared to the best selectivity recently reported by other authors for tin(II). The electrode was successfully applied to the determination of Sn²⁺ ion in waste water and various canned products.     

Studies on Mn(II) and Mn(IV) Complexes of an Unsymmetrical Bidentate Donor,N(4-Chlorophenyl)-Pyridine-2-Aldimine (ClL): Crystal Structure of [Mn(ClL)2(NCS)2]

The synthesis, characterisation and X-ray structure of an Mn(II) compound, [Mn(ClL)₂(NCS)₂], is described. Oxidation of the compound by H₂O₂ leads to a mononuclear Mn(IV) compound [Mn(ClL)(ClL')(NCS)₂]ClO₄·2H₂O where one of the ClL ligands is oxidised to the corresponding amide ClL'. Oxidation of [Mn(ClL)₂(NCS)₂] by Ce(IV), however, leads to a binuclear Mn(IV) compound [Mn₂O(ClL')₃(ClL)(H₂O)₂](NCS)₂ClO₄·2MeCN. Electron transfer behaviour of the compounds was investigated by cyclic voltammetry and differential pulse voltammetry.     

新型双核铜金属配合物为中性载体的硫氰酸根离子高选择性电极的研究

研制了基于N,N'-亚乙基(μ-5,5-亚甲基-二水杨醛根)(乙酰丙酮根)合二铜(II) [Cu₂(II)-MDSBAE]金属配合物为中性载体的阴离子选择性电极. 试验表明, 以Cu₂(II)-MDSBAE金属配合物为中性载体的电极对SCN^－具有良好的电位响应特性, 且呈现反Hofmeister行为,其选择性序列为: SCN^－＞Sal^－＞I^－＞ClO₄^－＞NO₃^－＞Br^－＞NO₂^－＞Cl^－≈SO₃^2－＞SO₄^2－. 在pH 5.0的磷酸盐缓冲体系中, 电极电位呈现近能斯特响应, 线性响应范围为1.0×10^－6～1.0×10^－1 mol/L, 斜率为－53. 6 mV/dec (25 ℃), 检测下限为8.1×10^－7 mol/L. 用交流阻抗研究了电极的响应机理, 并用紫外可见光谱技术测定了电极载体与SCN^－, Sal^－, I^－, ClO₄^－和NO₃^－离子间的配位数及缔合常数. 将该电极用于实验室废水和工业废水中硫氰酸根的检测, 其结果令人满意.     

Zn(II)‐Selective Membrane Electrode Based on Tetraazamacrocycle [Bzo2Me2Ph2(16)hexaeneN4]

A PVC membrane electrode using [Bzo₂Me₂Ph₂(16)hexaeneN₄] ( I ) as ionophore, oleic acid as lipophilic additive and o‐nitrophenyloctyl ether as plasticizer has been investigated as Zn(II)‐selective electrode. The membrane incorporating 34.9% (w/w) PVC, 2.3% I , 4.7% OA and 58.1% o‐NPOE gave linear response over the concentration range 2.82×10^?6?1.0×10^?1 M with a Nernstian slope of 28.5±0.2 mV/decade of concentration with a detection limit of 2.24×10^?6 M (0.146 ppm) and showed a response time of less than 10 s and could be used in pH range 2.5–8.5. High selectivity was obtained over a wide variety of metal ions. The proposed electrode was successfully used as an indicator electrode in potentiometric titration of zinc ions with EDTA and for determination of zinc in real samples.     

Ni(II) selective sensors based on Schiff bases membranes in poly(vinyl chloride)

The two nickel chelates of Schiff bases, 3-hydroxy-N-{2-[(3-hydroxy-N-phenylbutyrimidoyl)-amino]-phenyl}-N′-phenylbutyramidine (M₁) and bis-4-(ethyliminomethyl)naphthalene-1-ol (M₂), have been synthesized and explored as ionophores for preparing PVC-based membrane sensors selective to nickel ion. The influences of membrane compositions on the potentiometric response of the electrodes have been found to substantially improve the performance characteristics. The best performance was obtained with the electrode having a membrane composition (w/w; mg) of (M₁): PVC:NaTPB:CN in the ratio 5:150:5:150. The sensor shows a linear potential response for Ni²⁺ over a wide concentration range 1.6 × 10⁻⁷ to 1.0 × 10⁻² M with Nernstian compliance (30.0 ± 0.2 mV/decade of activity) within pH range 2.5-9.5 and a fast response time of 10 s. The sensor has been found to work satisfactorily in partially non-aqueous media up to 20% (v/v) content of methanol, ethanol, and acetonitrile and could be used for a period of 4 months. The analytical usefulness of the proposed electrode has been evaluated by its application in the determination of nickel in real samples. The practical utility of the membrane electrode has also been observed in the presence of surfactants.     

Thermodynamics,a suitable reporter in the design of mercury (II) ion selective electrodes

A fully functionalised calix[4]pyrrole derivative, namely, meso-tetramethyl-tetrakis[(diethylthiocarbamoyl)phenoxy] calix[4]-pyrrole, 1 has been synthesised and structurally characterised. Its complexing properties with metal cations in acetonitrile were investigated with particular emphasis on the thermodynamics of these systems. These data and those previously reported for a partially functionalised calix[4]arene based receptor, 5,11,17,23-tetra-tert-butyl[25,27 bis(diethylthiocarbamoyl)oxy]calix[4]arene, 2 were used to, i) further corroborate their use to predict the selectivity coefficients of carrier mediated mercury (II) ion selective electrodes (ISEs) and ii) to obtain approximate stability constant data from selectivity coefficients. The optimum working conditions of both electrodes were determined. It is shown that while the ISE based on 1 is characterised by a wider linear range and a lower mercury (II) detection than the one based on 2, the latter has the advantage of lower interference of other metal cations due to the much lower stability constants of bivalent cations relative to Hg(II). The response characteristics of these electrodes are compared with those found in the literature. SEM micrographs along with EDX spectra of the PVC membranes containing ionophore 1 or 2 unloaded and loaded with Hg(II) are reported.     

Bromo-substituted Mn(II) and Mn(III)-tetraarylporphyrins: synthesis and properties

Abstract

Mono-, tetra-, and octa-bromo substituted Mn(II)- and Mn(III)-tetraarylporphyrins were synthesized by reactions of manganese(II) chloride with corresponding porphyrin ligands or their Cd(II)-complexes in DMF. With the use of the metal exchange reaction, the time of the Mn-porphyrins formation is significantly reduced with increase in yield of final products in comparison with the complexation reaction. Mn(III)-tetraarylporphyrins reduce to the Mn(II)-porphyrins in DMF in the presence of NaOH and in pure DMF. The obtained compounds were identified using UV–vis and ¹H NMR spectroscopy, mass-spectrometry, and elemental analysis.     

Determination of Cr(VI) with Selective Sensing of Cr(VI) Anions by a PVC‐Membrane Electrode Based on Quinaldine Red

A dichromate‐selective PVC‐membrane electrode based on Quinaldine Red (an acridinium derivative) is described. The electrode exhibits rapid (< 30 s) and linear response to the activity of Cr(VI) anions in the range of 5.2 × 10^?6 ?1.0 × 10^?1 M dichromate with the limit of detection 2.5 × 10^?6 Mof Cr₂O₇^2?. The sensor is used as an indicator electrode in potentiometric determination of Cr(VI) anions and is also suitable for end‐point indication in the titrations of proper metal ions with dichromate under laboratory conditions. The proposed electrode has been applied to the direct potentiometric determination of Cr(VI) anions in water samples with satisfactory results.     

Nickel(II) Ion-Selective Electrode Based on 2,5-Thiophenyl bis(5-tert-Butyl-1,3-Benzoxazole

ABSTRACT

A PVC membrane sensor for Nickel (II) ions based on 2,5-thiophenyl bis(5-tert-butyl-1,3-benzoxazole) as membrane carrier was prepared. The sensor exhibits a Nernstian response for Ni²⁺ ions over a wide concentration range (10^?2–10^?5M). It has a relatively fast response time and can be used for at least 2 months without any considerable divergence in potentials. The nature of the plasticizer, the additive, the concentration of internal solutions in the electrodes and the composition of the membrane were investigated. The proposed membrane electrode revealed very good selectivities for Ni²⁺ over a wide variety of other metal cations and could be used in pH range of 4.0–8.0. It was successfully applied for the direct determination of Ni²⁺ in solution and as an indicator electrode in potentiometric titration of nickel ion in both water and 85% acetonitrile solutions.     

涂丝Ag-Ag2S电极测定水体中微量氰化物的研究

本文报道了涂丝Ag-Ag2S电极测定水体中微量氰化物(CN-)的分析方法。该方法对现用的Ag(CN)2-指示剂配制方法以及使用浓度作了新的改进,加之成功地在ISAB中引入有机溶剂等,较大程度地提高了测定CN-的灵敏度。该方法测定CN-的线性范围为1.0×10-3～1.0×10-7mol/L,检出限可达4.0×10-8mol/L,标准偏差小于0.015,回收率为99%～104%。本方法与比色法对照,相对误差≤1.3%,结果令人满意。