新型含氮化合物作中性载体pH选择电极研究

本文合成了具优良pH响应的对称、非对称长链叔胺及菸酸衍生物离子载体用于制备pH电极,获较宽pH线性响应范围,并试用于人体血浆pH值测定、气敏电极制备以及指示酸碱滴定。结合量子化学计算研究了载体的结构与其电位响应的构效关系;通过建立较一般的电极电位方程对有关超Nernstian应进行了解释。     

基于2,3-丁二酮双缩氨基硫脲为中性载体的新型银离子选择性电极的研究

研究了基于2,3-丁二酮双缩氨基硫脲为中性载体的聚氯乙烯(PVC)膜电极, 该电极对银离子(Ag^＋)具有优良的电位响应性能. 在pH＝3.0的NaOH-HNO₃体系中, 该电极对Ag^＋电极电位呈现近能斯特响应, 线性响应范围为3.0×10^－6～1.0×10^－2 mol/L, 斜率为52.6 mV/decade (20 ℃), 检测下限为1.0×10^－6 mol/L. 相对于常见的阳离子, 该电极对Ag^＋表现出良好的选择性. 采用交流阻抗技术研究了电极响应机理, 并将电极初步应用于回收率实验, 结果令人满意.     

硒功能化杯芳烃载体银离子选择性膜电极的研究

合成6个硒功能化杯芳烃为载体,采用双层夹心膜电位法直接测定了溶剂聚合物膜中载体与金属离子生成的络合物生成常数。制备并考察了以硒功能化杯芳烃为载体的银离子选择性电极的性能,发现以载体6为银离子选择性电子的载体,制成的膜电极,用作Ag^ 电位滴定Cl^-的指示电极,效果最佳。     

混合型中性载体PVC膜pH电极的研究

本文以菸酸十八烷基酯和二辛基十八胺两性载体混合研制成ＰＶＣ膜ＰＨ电极，采用正交实验设计优化了电极的膜组成，测得电极的ＰＨ线性响应范围为１．８－１２．１，秦为５５．６ｍＶ／ｐＨ（１８℃），获得满意结果。     

有机锡化合物为中性载体的高选择性硫氰酸根离子电极

使用硫氰化银与硫化银作膜活性物质的固态硫氰酸根离子选择电极,由于受卤素离子如Cl^-、Br^-和I^-干扰很大而限制了应用.以钴(Ⅲ)卟啉或维生素B₁₂衍生物为载体的电极对SCN^-有较高的选择性^[1,2],使SCN-选择电极得到了较大的发展.     

对钠离子有选择性的中性载体

合成了十一种中性离子载体,用它们制成钠离子选择性电极,测定了电极的选择性系数并与文献报道的类似电极进行了比较。     

新型中性载体硫氰酸根离子选择电极研究

系统研究了新型Schiff碱[N,N'-双-(4-苯偶氮水杨醛)缩邻苯二胺]过渡金属配合物的阴离子响应行为.实验结果表明,配合物中心金属原子的结构与电极的响应行为之间有非常密切的构效关系,其中Mn(Ⅱ)的配合物对硫氰酸根有优良的电位响应性能和选择性,该电极的线性范围为0.14.3×10^-6mol/L,斜率为-58.0mV/dec.,其反Hofmeister选择性次序为SCN^->I^->Sal^->PhCO₂^->ClO₄^->NO₂^->Br^->Ac^->NO₃^->Cl^-.通过交流阻抗和膜相中荷电离子的添加实验证实,该电极对阴离子的响应系中性载体作用机制.该电极具有读数稳定,选择性和重现性好等优点,可直接应用于废水中硫氰酸盐的测定.     

选择性中性载体硫氰酸根电极的研究

离子选择性电极由于操作方便,制作简单,成本低廉,近年来得到了快速的发展[1]。基于经典的离子交换剂如季铵盐、季钅粦盐及带正电荷的金属配合物作为载体的溶剂聚合膜电极对阴离子的选择性呈现出Hofmeister选择性序列[2],其选择性次序为:C lO4->SCN->I-≈Sal->NO3->Br->NO2->C l     

以新型杯[6]衍生物为探针的银离子选择性电极研究

以新型杯芳烃衍生物 ( 5,1 1 ,1 7,2 3 ,2 9,3 5-六 [( 4-苯甲酸 )偶氮基 ]-3 7,3 8,3 9,40 ,41 ,42 -六羟基杯 [6 ]芳烃 )为探针构成 PVC膜离子选择性电极 ,发现该探针对银离子有选择性 ,该电极在 1 .0× 1 0 - 5～ 2 .0× 1 0 - 2 mol·L- 1范围内有典型的 Nernst响应。对常见碱金属、碱土金属和过渡金属离子有很好的选择性 ,而 Hg2 + 、Cr3 + 、Cs+、Na+、Fe2 +有一定程度的干扰 ;此电极稳定且重复性好 ,作为指示电极已成功地应用于 Na Cl滴定 Ag NO3 体系     

新型杯芳烃银离子选择电极的研究

报道了５,１１,１７,２３－四（１,１－二甲基乙基）－２５,２７－二羟基２６,２８－二「２－乙基硫）乙氧基」杯「４」芳烃为银离子载体的ＰＶＣ膜电极的研制。该银离子选择电极不仅对银离子有良好的灵敏度和高选择性,在１０＾－１－１０＾－５ｍｏｌ／Ｌ浓度范围内有良好的线性,能斯特响应为５６ｍＶ／ｐｅＡｇ．（２５℃）碱金属、碱土金属及过渡金属离子不干扰银的测定;而且对某些阴离子也表现出近似能斯特响应（５０ｍＶ／ｐｃｘ－）。用该电极对人工试样中银含量进行测定,结果与原子吸收光度法相符。     

5,10,15-Tris(pentafluorophenyl)corrole as highly selective neutral carrier for a silver ion-sensitive electrode

A new highly selective silver(I) electrode was prepared with a PVC membrane using 5,10,15-tris(pentafluorophenyl)corrole as an electroactive material, 2-nitrophenyl octyl ether (o-NPOE) as a plasticizer and sodium tetraphenylborate (NaTPB) as an additive in the percentage ratio of 3:3:62:32 (corrole:NaTPB:o-NPOE:PVC, w:w). The electrode exhibited linear response with a near Nernstian slope of 54.8 mV/decade within the concentration range of 5.1 × 10⁻⁶ to 1.0 × 10⁻¹ M silver ions, with a working pH range from 4.0 to 8.0, and a fast response time of <30 s. Selectivity coefficients for Ag(I) relative to a number of interfering ions were investigated. The electrode is highly selective for Ag(I) ions over a large number of mono-, bi-, and tri-valent cations. Common interferents like Hg²⁺ and Cd²⁺ show very low interfering effect on the silver assay, which is valuable property of the proposed electrode. Several electroactive materials and solvent mediators have been compared and the experimental conditions were optimized. The sensor was applied to the determination of silver in real ore samples with satisfied results.     

双水杨醛乙二胺中性载体的锰离子电极的研究

研究以双水杨醛乙二胺[BBG]为中性载体,制备了一种对锰离子(Mn2 )具有优良的电位响应特性的离子选择性电极,其选择性次序为:Mn2 >>Rb ＞Al3 ＞Ca2 ＞Bi3 ＞Cu2 ＞Co2 ＞Fe3 ＞Cd2 ＞Ba2 ＞Ce3 ＞Cr3 ＞La3 ＞Na .该电极在pH 3.0的NaOH-HNO3溶液体系中具有最佳的电位响应,在1.0×10-1mol/L～ 1.0×10-5 mol/L Mn2 浓度范围呈近能斯特响应,斜率为32.0 mV/p Mn2 (25 ℃),检测下限为8.0×10-6 mol/L.采用交流阻抗和紫外光谱分析技术研究了配合物本身的结构对电极电位响应行为的作用机理.将该电极用于实际样品的测定,获得满意的结果.     

Calix[2]furano[2]pyrrole and related compounds as the neutral carrier in silver ion-selective electrode

The performance of calix[2]furano[2]pyrrole and related compounds used as neutral carriers for silver selective polymeric membrane electrode was investigated. The silver ion-selective electrode based on calix[2]furano[2]pyrroles gave a good Nernstian response of 57.1 mV per decade for silver ion in the activity range 1×10⁻⁶ to 1×10⁻² M. The present silver ion-selective electrode displayed very good selectivity for Ag⁺ ion against alkali and alkaline earth metal ions, NH₄⁺, and H⁺. In particular, the present Ag⁺-selective electrode exhibited very low responses towards Hg²⁺ and Pb²⁺ ions. The potentiometric selectivity coefficients of the silver ion-selective electrode exhibited a strong dependence on the solution pH. In particular, the response of the electrode to the Hg²⁺ activity was greatly diminished at pH 2.5 compared to that at pH 5.0. Overall, the performance of the present silver ion-selective electrode based on the ionophore, calix[2]furano[2]pyrrole, is very comparable to that of the electrode prepared with the commercially available neutral carrier in terms of slope, linear range, and detection limits.     

Ytterbium-selective polymeric membrane electrode based on substituted urea and thiourea as a suitable carrier

Plasticized membranes using 1-phenyl-3-(2-thiazolyl)-2-thiourea (PTT) and 1-phenyl-3-(2-thiazolyl)-2-urea (PTU) have been prepared and explored as ytterbium ion-selective sensors. Effect of various plasticizers, viz. chloronaphthalene (CN), o-nitrophenyloctyl ether (o-NPOE), dibutylphthalate (DBP), dioctylsebacate (DOS) and anion excluders, sodium tetraphenylborate (NaTPB) and oleic acid (OA) was studied and improved membrane performance was observed. Optimum performance was noted with membrane of PTT having composition of PTT (3.5):PVC (80):DOS (160):NaTPB (1.5) in mg. The sensor works satisfactorily in the concentration range 1.2 × 10⁻⁷ to 1.0 × 10⁻² M (detection limit 5.5 × 10⁻⁸ M) with a Nernstian slope of 19.7 mV decade⁻¹ of activity. Wide pH range (3.0-8.0), fast response time (10 s), non-aqueous tolerance (up to 20%) and adequate shelf life (12 weeks) indicate the vital utility of the proposed sensor. The proposed electrode comparatively shows good selectivity for Yb³⁺ ion with respect to alkali, alkaline earth, transition and rare earth metals ions and can be used for its determination in binary mixtures and sulfite determination in white and red wine samples.     

A highly sensitive PVC membrane iodide electrode based on complexes of mercury(II) as neutral carrier

A novel solvent polymeric membrane electrode based on bis(1,3,4-thiadiazole) complexes of Hg(II) is described which has excellent selectivity and sensitivity toward iodide ion. The electrode, containing 1,4-bis(5-methyl-1,3,4-thiadiazole-2-yl-thio)butanemercury(II) [Hg(II)BMTB(NO₃)₄], has a Nernstian potentiometric response from 2.0×10^–8 to 2.0×10^–2 mol L^–1 with a detection limit of 8.0×10^–9 mol L^–1 and a slope of –59.0±0.5 mV/decade in 0.01 mol L^–1 phosphate buffer solution (pH 3.0, 20°C). The selectivity sequence observed is iodide>bromide>thiocyanate>nitrite>nitrate>chloride>perchlorate>acetate>sulfate. The selectivity behavior is discussed in terms of the UV–Vis spectrum, and the process of transfer of iodide across the membrane interface is investigated by use of the AC impedance technique. The electrode was successfully applied to the determination of iodide in Jialing River and Spring in Jinyun Mountains, with satisfactory results.     

Improved lithium ion-selective electrode based on a lipophilic diamide as neutral carrier

A lithium ion-selective solvent polymeric membrane based on the lipophilic diamide N,N,N',N',-tetraisobutylcyclohexane-cis-l,2-dicarboxylic diamide is described. Selectivity coefficients for lithium ions over other alkali metal ions are greater than 100 and over alkaline earth metal cations are about 1000.     

Organoselenide as a Novel Ionophore for a Silver-Selective Membrane Electrode

Abstract

Three selenium-containing compounds, diphenyl selenide, benzyl phenyl selenide and dibenzyl selenide were used as neutral carriers to make a Ag⁺-selective membrane electrode. All three compounds exhibited higher sensitivity to Ag⁺ than the corresponding sulfides and ethers. The highest sensitivity was obtained by dibenzyl selenide and an electrode constructed using this carrier and bis(l-butylpentyl) adipate as a membrane solvent in a poly(vinyl chloride) membrane matrix exhibited a near-Nernstian response to Ag⁺ in the concentration range from 1 x 10^?5 to 1 x 10^?2 M with a slope of 52 mV per concentration decade. The lower limit of detection was around 1 μM. The ion selectivity of this electrode for Ag⁺ was over 10⁴ times that for other metal cations. Dibenzyl selenide and Ag⁺ interactions were examined by ¹H-NMR spectroscopy.     

A hydrogen ion-selective liquid-membrane electrode based on tri-n-dodecylamine as neutral carrier

An electrically neutral hydrogen ion-selective carrier, tri-n-dodecylamine, is used as the active component for liquid-membrane electrodes. The observed ion selectivities are superior to those of previously described pH-sensitive liquid-membrane electrodes. The electrode characteristics permit the study of intracellular as well as extracellular hydrogen ion activities.     

异菸酸十六烷酯作中性载体的镍离子选择电极

本文报道了一种镍离子选择性电极,它以我们合成的异菸酸十六烷酯作中性载体,该电极对浓度范围为10~(-1)～8×10~(-5)mol/L的镍离子有线性响应,斜率为-25.5±0.4 mV/pC_((Ni)~(2+))(20℃).相对于钠、钾、锂、钙、锡、铁、钴、铜离子的选择性系数分别为:8.1×1~(-5)、8.6×10~(-5)、8.2×10~(-5)、4.1×10~(-3)、7.5×10~(-4)、3.2×10~(-2)、8.0×10~(-2)、4.4×10~(-1).电极重现性优良,响应较快,用交流阻抗法研究了电极膜的传导机理,实验结果表明电极过程受扩散过程控制。