杯芳烃磷酸酯为载体铅离子选择性膜电极的研究

1引言研制中性载体PVC膜离子选择电极,关键是设计及选择合适的载体。杯芳烃衍生物作为高选择性载体已成功地用于离子选择电极上。本研究合成了两种新的对-叔丁基杯[4]芳烃磷酸酯类衍生物,以此化合物为载体制备了两种铅离子选择性膜电极,并对电极的性能进行了研究。2实验部分2.1     

新型杯芳烃衍生物银离子选择电极的研究

以苯并噻唑、羟基硫醚的杯[4]芳烃衍生物为载体,制备了银离子选择电极（Ag^ -ISEs),研究了不同极性的膜增塑剂DBP、o-NPOE对电极性能的影响。研究结果表明,苯并噻唑取代的杯[4]芳烃作载体的Ag^ -ISEs对银离子有很好的能斯特响应和较宽的线性范围,低的检测限,对碱金属、碱土金属、过渡金属离子和铅离子有极高的选择性,汞离子对银离子的干扰很小,优于Ag2S固态商品电极。研制的Ag^ -ISEs可用于电位滴定的指示电极,结果令人满意。     

以含噻二唑的对叔丁基杯[4]芳烃衍生物为载体的PVC膜铅离子选择电极的研究

制备了以25,27-二(2-噻二唑基硫代乙氧基)-26,28-二羟基-5,11,17,23-四叔丁基杯[4]芳烃为载体的聚氯乙烯(PVC)膜铅离子选择电极;研究了电极膜中增塑剂种类及载体和离子定域体(KTpClPB)含量对电极性能的影响。实验结果表明:具有最佳组成的膜电极对Pb2 有良好的灵敏度,在0.01～100mmol/L的浓度范围内响应斜率为29.1mV/decade,检测下限为6.4μmol/L,碱金属、碱土金属及大多数过渡金属离子不干扰Pb的测定。该电极可在低于20%的甲醇、乙醇和丙酮水溶液中使用,可作为准确滴定Pb2 的电位滴定指示电极,并能用于实际样品中Pb含量的直接测定。     

用于高性能铅离子选择电极的含氮有机物载体

本文系统地综述高性能铅离子选择电极中掺杂于膜内的含氮有机物铅离子传感载体,如双席夫碱、吡啶酰胺、酰羟胺、苯腙,以及载体分子结构特征与铅离子电极性能之间的关系。电极对铅离子的选择性能与载体分子结构密切相关,无论是在载体还是在膜基体中引入氰基都可以明显改善铅离子电极探测下限;加强传感机理的深入研究,为高性能载体的研究指明方向。     

以芴的衍生物为载体的PVC膜铜(Ⅱ)离子选择性电极的研究

报道了4,5-二氮杂-9-对甲氧基亚氨基芴为铜(Ⅱ)离子载体的聚氯乙烯(PVC)膜电极的研制;研究了电极膜中增塑剂种类及载体和离子定域体(KTpClPB)含量对电极性能的影响,得到了电极膜中各组分的最佳质量比为m(载体):m(PVC):m(o-NPOE):m(KTpClPB)=2.0:32.3:65.6:0.1;该选择电极对铜(Ⅱ)离子有良好的能斯特响应性能和较高的选择性,线性响应范围为10-6～10-2 mol/L,斜率为29.9 mV/decade;电极具有优良的重复性和稳定性,可用于电位滴定Cu^2 的指示电极和水体中铜离子的测定.     

四苯硼酸盐PVC膜锂离子选择电极的研究

四苯硼酸盐与介体溶剂所组成的PVC膜对碱金属离子的选择性同溶剂的性质有关^[1]。因此,可选择适当的溶剂研制碱金属离子选择电极。本工作研究了以DOPP(苯基膦酸二辛酯)或TBP(磷酸三丁酯)为介体溶剂,NaTPB(四苯硼钠)或KTPB(四苯硼钾)为活性物质的PVC膜对金属离子的选择响应。结果表明,DOPP为溶剂、KTPB为活性物质可制备性能良好的PVC膜Li⁺选择电极。该电极的电化学性能接近或优于新近报道的几种Li⁺选择电极^[2~7]。     

用铅离子选择电极研究难溶盐组分的配位平衡—关于铅-氯,铅-溴体系的配位平衡

铅离子选择电极在配体过量的条件下对游离铅离子的响应灵敏度很高,应用这种电极已测定了铅-氟配合物的各级稳定常数,本文继续研究了铅电极测定铅-氯,铅-溴配合物稳定常数的方法并在数据处理上将经典的逐级外推法与徐光宪的对数作图法结合起来提高了测定各级稳定常数的可靠性。     

杯芳烃LB膜修饰电极及其识别性能

为了得到性能好的修饰电极,尝试使用不同的杯芳烃制作LB膜修饰电极,研究了不同空腔大小的和不同上缘取代基的杯芳烃LB膜成膜情况,发现对叔丁基杯芳烃和对烯丙基杯[4]芳烃都可以得到稳定的LB膜,杯环大小可以影响成膜的平均分子占有面积。不同取代基的杯芳烃识别金属铊离子的性能不同,叔丁基基本没有特别的响应,烯丙基有较好的响应,这应归因于电极表面烯丙基对铊离子的吸附或络合作用。     

双呋喃甲醛丙二胺席夫碱铜(Ⅱ)络合物为载体的选择性碘离子电极的研究

以易于制备的3种二醋酸双(呋喃甲醛)缩1,3-丙二胺铜(Ⅱ)、钴(Ⅱ)、锰(Ⅱ)金属络合物为载体制备了阴离子选择性电极,发现以二醋酸双(呋喃甲醛)缩1,3—丙二胺Ca(Ⅱ）[Cu(Cu（Ⅱ）—BFADP]络合物为载体的PVC膜电极能明显改善对I^-的响应。采用紫外光谱分析技术和交流阻抗技术研究了电极对I^-响应机理,并将电极初步应用于药品分析,结果令人满意。     

基于无序介孔碳的全固态自支撑聚合物膜铅离子选择性微型电极

将无序介孔碳材料填充到尖端直径约150 μm的毛细玻璃管内,利用其多孔结构将铅离子选择性敏感 膜吸附于电极尖端内部,制备了基于无序介孔碳的全固态自支撑聚合物膜铅离子选择性微型电极（Pb2+ －ISμE）。 采用循环伏安法（CV）和电化学阻抗法对所制备电极的电化学性质进行表征,并考察了其电位响应性能。结果 表明,基于无序介孔碳的微型电极具有微电极所特有的“S”型循环伏安曲线,且由于电极材料的多孔性表现 出较大的双电层电容特性,所构建的Pb2+ －ISμE测定Pb2+ 的线性范围为1. 0 × 10－7 ～1. 0 × 10－4 mol/L,响应斜率 为（28. 9 ± 0. 5）mV/dec,检出限为 4. 0 × 10－8 mol/L。该 Pb2+ －ISμE 表现出良好的选择性、稳定性和重复性, 并成功应用于海岸带沉积物加标孔隙水中Pb2+ 的测定。该文为微型电极的制备提供了一种简单、便捷的方法, 并为微环境或微量样品中离子的测定提供了一种有效的检测手段。     

Poly(vinyl chloride) membrane cesium ion-selective electrodes based on lipophilic calix[6]arene tetraester derivatives

New lipophilic tetraesters of calix[6]arene and calix[6]diquinone are investigated as cesium ion-selective ionophores in poly(vinyl chloride) membrane electrodes. For an ion-selective electrode based on calix[6]arene tetraester I, the linear response is 1x10(-6)-1x10(-1) M of Cs(+) concentrations. The selectivity coefficients for cesium ion over alkali, alkaline earth and ammonium ions are determined. The detection limit (log a (Cs (+))=-6.31) and the selectivity coefficient (log k (Cs (+),Rb (+))(pot )=-1.88) are obtained for polymeric membrane electrode containing calix[6]arene tetraester I.     

Selective electrodes for silver based on polymeric membranes containing cali

Silver ion-selective electrodes were prepared with polymeric membranes based on two calix[4]arene derivatives functionalized by two hydroxy and two benzothiazolylthioethoxy groups. The electrodes all gave a good Nernstian response of 58mV decade(-1) for silver in the activity range 5 x 10(-6)-10(-1) M, the limits of detection reached 10(-5.8) M and exhibited high selectivity towards alkali, alkaline earth and some transition metal ions. The electrode was used as indicator electrode in titrations of Ag+ with Cl- ion.     

Cesium-ion selective electrodes based on calix[4]arene dibenzocrown ethers

Four calix[4]arene dibenzocrown ether compounds have been prepared and evaluated as Cs(+)-selective ligands in solvent polymeric membrane electrodes. The ionophores include 25,27-bis(1-propyloxy)calix[4]arene dibenzocrown-6 1, 25,27-bis(1-alkyloxy)calix[4]arene dibenzocrown-7s 2 and 3, and 25,27-bis(1-propyloxy)calix[4]arene dibenzocrown-8 4. For an ion-selective electrode (ISE) based on 1, the linear response concentration range is 1x10(-1) to 1x10(-6) M of Cs(+). Potentiometric selectivities of ISEs based on 1-4 for Cs(+) over other alkali metal cations, alkaline earth metal cations, and NH(4)(+) have been assessed. For 1-ISE, a remarkably high Cs(+)/Na(+) selectivity was observed, the selectivity coefficient (K(Cs,Na)(Pot)) being ca. 10(-5). As the size of crown ether ring is enlarged from crown-6 (1) to crown-7 (2 and 3) to crown-8 (4), the Cs(+) selectivity over other alkali metal cations, such as Na(+) and K(+), is reduced successively. Effects of membrane composition and pH in the aqueous solution upon the electrode properties are also discussed.     

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.     

Hydrogen ion-selective poly(vinyl chloride) membrane electrode based on a calix[4]arene.

A hydrogen ion-selective poly(vinyl chloride) membrane electrode was constructed using 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetracyanomethoxycalix[4]arene as a neutral carrier. The electrode showed an apparent Nernstian response in the 2-11.5 pH range with a slope of 54.0 +/- 0.2 mV/pH at 20 +/- degrees C. This electrode showed a rapid response of the emf to changes in the pH, high ion selectivity with respect to lithium, sodium and potassium, and characteristics similar to those reported for the conventional pH glass membrane electrode. It can be used as a potentiometric indicator electrode in hydrofluoric acid solutions. The effects of iodide, thiocyanate, perchlorate and bromide on the characteristics of the electrode were also considered.     

钳状杯[4]芳烃为探针的固态PVC膜汞离子选择性电极

全固膜选择性电极(All solid-state selective electrode,ASSE)综合晶体电极和膜电极的优点,具有线性范围宽、检测限低,能真实地体现膜性能等特点,ASSE主要有涂线电极(Coated wire electrode,CWE)、填充固体电解质或配合物的膜电极和电沉积型聚合物膜电极等。     

Calix[4]Arenes in the partial cone conformation as ionophores in silver ion-selective electrodes

Two calix[4]arene derivatives, in the partial cone conformation, with sulfur-containing functionalities, were tested as neutral carrier ionophores in potentiometric silver-selective electrodes of conventional membrane and membrane-coated glassy carbon electrode types. Comparison with a calix[4]arene in the cone conformation was made. The membranes were prepared using either 2-nitrophenyl octyl ether or bis(ethylhexyl)sebacate as plasticizers and potassium tetrakis(p-chlorophenyl)borate as the lipophilic salt in a poly(vinyl chloride) matrix. Both calix[4]arenes yielded electrodes of good sensitivity (approx. 47 mV dec⁻¹) in the range 10⁻⁴–10⁻¹ M and excellent selectivity [log K_Ag,_MH+ < −1.5] of transition, alkali and heavy metal cations, including sodium, mercury(II) and lead(II) cations. Temperature effects and reproducibility of response were determined and the interfering effects of mercury(II) and lead (II) ions on the membranes were noted. The partial cone conformation allows improved selectivity over certain cations relative to calix[4]arenes in the cone conformation.     

Silver(I) ion-selective membrane based on Schiff base-p-tert-butylcalix[4]arene

A PVC membrane electrode for silver(I) ion based on Schiff base-p-tert-butylcalix[4]arene is reported. The electrode works well over a wide range of concentration (1.0 x 10(-5)-1.0 x 10(-1) mol dm-3) with a Nernstian slope of 59.7 mV per decade. The electrode shows a fast response time of 20 s and operates in the pH range 1.0-5.6. The sensor can be used for more than 6 months without any divergence in the potential. The selectivity of the electrode was studied and it was found that the electrode exhibits good selectivity for silver ion over some alkali, alkaline earth and transition metal ions. The silver ion-selective electrode was used as an indicator electrode for the potentiometric titration of silver ion in solution using a standard solution of sodium chloride; a sharp potential change occurs at the end-point. The applicability of the sensor to silver(I) ion measurement in water samples spiked with silver nitrate is illustrated.     

Molecular design of calixarene-based ion-selective electrodes

In order to obtain insights into relationships between the calix[4]arene structure and the ion selectivity in the electrode system, 20 ionophoric calix[4]arenes were synthesized and their ion selectivity (with Na⁺ as a standard) estimated. Among these ionophoric calix[4]arenes, 25,26,27,28-tetrakis[(ethoxycarbonyl)methoxy]-p-t-octylcalix[4]arene afforded the highest logK _NA,M ^pot value (–3.1) in the presence of 2-fluorophenyl-2-nitrophenylether (10) as the best of 13 plasticizers. This is the first example in which the Na⁺/K⁺ selectivity exceeds a factor of 10³ in the electrode system based on the neutral carrier. The high Na⁺ selectivity is attributed to modification of the upper rim which ostensibly has no relation with the component of the cavity. This paper demonstrates the potential relationships between the unique structure of the calix[4]arene-based ligands and selectivity performance for the design of ion-selective electrodes.     

Studies on the Synthesis and Property of A New Podand-armed Calix[4]arene Derivative

Pendant groups such as esters, amides, carboxylic acids, etc. have been grafted at thelower rim of call-c[41arene to produce a variety of novel ionophores'. The call-c[4]areneswith different functional groups have showed coordination diversity for alkali metalcanons2. In this paper we described the synthesis of a new calixarene derivative withpodand-armed functional group and the property as ionophore and extractant for cesiumIOn.25, 26, 27, 28-Tetrakis[2-(o-methoxyphenoxy) 3 wassynthesized f…