二氮杂四烯基金属配合物中性载体高选择性水杨酸根离子电极的研究

首次研究了基于二氮杂四烯基钴（Ⅱ）金属配合物{3,3′-[1,2-亚乙基（亚氨 基次甲基）]二－2,4－戊二酮基合钴（Ⅱ）}[Co(Ⅱ）-EBIBP]为中性载体的阴离 子选择性电极。该电极对水杨酸根（Sal^-)呈现出优良的电位响应性能和选择性, 且呈现出反Hofmeister序列行为,其选择性次序为Sal^->>I^->SCN^->NO2^- >SO4^2->NO3^->ClO4^->Br^->Cl^-。采用交流阻抗技术和光谱分析技术研究了电极 的响应机理。结果表明,配合物中心金属原子的结构以及载体本身的结构与电极的 响应行为之间有非常密切的构效关系。并将电极用于药品分析,其结果令人满意。     

双安息香缩三乙四胺双核钴硫氰酸根的离子电极研究

季铵盐型阴离子选择性电极由于其电位选择性往往表现出Hofmeister顺序,故使其应用受到限制,因此,研究呈现反Hofmeister行为的阴离子选择性电极已成为离子电极研究领域中重要的研究方向之一。近年来,人们研制出了以金属配合物为中性载体且呈现反Hofmeister行为的阴离子选择电极,本实验室也分别研究了以Schiff碱金属配合物及二氮杂四烯基金属配合物为载体的碘离子和水杨酸根离子电极,但上述电极多数是以单核金属配合物为载体,以双核金属配合物作为载体的电极则很少。     

苯甲醛丙氨酸金属配合物中性载体水杨酸根离子电极的研究

首次研究了基于苯甲醛丙氨酸合钴(Ⅱ)金属配合物[Co(Ⅱ) BBAA]为中性载体的PVC膜电极。该电极对水杨酸根(Sal-)具有优良的电位响应性能和->选择性并呈现出反Hofmeister选择性行为,其选择性次序为Sal->ClO42->SO42-。在pH5.0的磷酸盐缓->NO2->Br->Cl->SO3SCN->I->NO3冲体系中,电极电位呈现近能斯特响应,线性响应范围为3.2×10-5～1.0×10-1mol L,斜率为-56.4mV dec(20℃),检测下限为9.0×10-6mol L。采用交流阻抗技术和紫外可见光谱技术研究了电极的响应机理,结果表明配合物中心金属原子的结构以及载体本身的结构与电极的响应行为之间有非常密切的构效关系。电极可用于药品分析。     

新型Schiff碱双核铜(Ⅱ)配合物为载体的水杨酸根离子电极的研究

研究了5-溴水杨醛缩三乙烯四胺双核铜(Ⅱ)配合物为载体的高选择性水杨酸根离子中性膜电极。该电极对水杨酸根离子(Sal-)具有优良的电位响应特性并呈现出反Hofmeister选择性行为,其选择性次序为:Sal-ClO4-SCN-I-NO3-Br-SO42-Ac-NO2-Cl-SO23-。电极在pH=5.0的磷酸盐缓冲体系中,与Sal-在4.0×10-6～1.0×10-1mol/L浓度范围内呈近能斯特响应,斜率为58.0mV/dec(28℃),检出限为1.0×10-6mol/L。采用紫外可见光谱技术研究了电极响应机理。将该电极应用于药品分析,结果令人满意。     

新型高选择性水杨酸根离子电极的研究

报道了基于乙酰丙酮缩二亚丙基三胺合钴(Ⅱ)(Co(Ⅱ)-BAEDDPA)为载体的溶剂聚合膜阴离子敏感电极,该电极对水杨酸根离子(Sal-)具有高的电位选择性和灵敏度,且呈现反Hofm e ister选择性行为,其选择性序列为Sal->C lO4->SCN->I->B r->NO2->NO3->SO32->C l->SO42-。该电极电位对水杨酸根离子呈近能斯特响应,其线性范围为2.0×10-6~1.0×10-1mol/L Sal-;斜率为-68.8 mV/dec;检出限为6.0×10-7mol/L Sal-。采用交流阻抗和光谱分析技术研究了电极的响应机理,并将电极用于药品分析,结果令人满意。     

基于酞菁铜衍生物为载体的电极对水杨酸根的选择性电位响应

本文以2,9,16,23-四硝基酞菁铜(II) (Cu(II)TNPc) 和2,9,16,23-四氨基酞菁铜(II) (Cu(II)TAPc) 为载体制备PVC聚合膜,构建了水杨酸根选择性电极,并探讨了该电极的选择性响应性能。研究了增塑剂的性质、载体的含量及阴、阳离子添加剂对电极电位响应的影响。结果表明,基于Cu(II)TNPc为载体的PVC膜电极对水杨酸根 (Sal－) 呈现出优先选择性电位响应。具有最佳电位响应的电极的膜组成是：(w/w) 3.0% Cu(II)TNPc,67.0% o-NPOE,29.5% PVC和0.5% NaTPB。基于该组成的电极的线性响应范围为1.0×10－1－9.0×10－7 mol·L－1,检测下限为7.2×10－7 mol·L-1,斜率为－59.8±0.5 mV/decade;其响应快速,稳定性好,适宜的pH范围是3.0－7.0。并成功运用于了实际样品中水杨酸含量的测定,获得令人满意的结果。     

基于双核三苄基甲醇锡(Ⅳ)对苯二甲酸酯配合物为中性载体的硫氰酸根电极的研究

研究了双核三苄基甲醇锡(Ⅳ)对苯二甲酸酯配合物［Sn(Ⅳ)-BTMTT］为中性载体的PVC膜阴离子选择性电极。这类电极对硫氰酸根离子呈现出优良的电位响应性能和选择性,并呈现反Hofmeister序列行为。其选择性序列为:SCN-＞I-＞Ac-＞－NO＞2－2NO＞－4ClO＞Cl-＞3－4SO,该电极在pH＝3.0的磷酸盐缓冲体系中对SCN-在0.1～8×10-5mol／L浓度范围内呈超能斯特响应,斜率为-77.3mV／dec,检出限为4.0×10-5mol／L。采用交流阻抗及紫外光谱研究了阴离子与载体的作用机理。该电极具有响应快、重现性好、制备简单等优点。将该电极用于废水分析,结果令人满意。     

新型镍配合物中性载体高选择性水杨酸根离子电极的研究

首次研究了基于苯甲醛丙氨酸合镍(Ⅱ)金属配合物[Ni(Ⅱ) -BBAA]为中性载体的PVC膜电极。该电极对水杨酸根(Sal -)具有优良的电位响应性能和选择性并呈现出反Hofmeister选择性行为 ,其选择性次序为Sal->ClO-4>SCN->I-> -2NO> 3-NO>Br->Cl->SO32- >SO42-。在pH5.0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2.2×10 -5～1.0×10 -1mol/L,斜率为 -55.8mV/dec(20℃) ,检出限为8.0×10-6 mol/L。采用交流阻抗技术和紫外可见光谱技术研究了电极的响应机理 ,结果表明配合物中心金属原子的结构以及载体本身的结构与电极的响应行为之间有非常密切的构效关系。该电极具有响应快、重现性好、检出限低、制备简单等优点。将电极用于药品分析 ,其结果令人满意     

新型异双四齿双席夫碱铜(Ⅱ)配合物为中性载体的高选择性硫氰酸根离子选择电极的研究

研究了用乙二胺与乙酰丙酮、水杨醛反应合成的一种异双四齿席夫碱铜(Ⅱ)配合物[Cu(Ⅱ)-L]为中性载体的PVC膜电极,该电极对硫氰酸根离子(SCN-)具有优良的电位响应特性并呈现出反Hofmeister选择性行为,其选择性次序为:SCN->Sal->ClO4->I->Br->NO3->Cl->NO2->SO32->SO42->H2PO4-。电极在pH 5.0的磷酸盐缓冲体系中,对SCN-在1.0×10-1~2.0×10-6mol/L浓度范围内呈近能斯特响应,斜率为-57.8 mV/dec(25℃),检出限为1.0×10-6mol/L。利用交流阻抗和紫外可见光谱初步研究了阴离子与载体的作用机理,结果表明配合物中心金属原子的结构以及载体本身的结构与电极的响应行为之间有非常密切的构效关系。将电极初步应用于实际样品废水中,结果与HPLC法相符合。     

基于硫氮杂冠醚离子载体的高选择性聚合物膜汞离子选择性电极

以硫氮杂冠醚化合物为离子载体,制备了一种高选择性聚合物膜汞离子选择性电极.通过对电极膜的组成及活化条件进行优化,电极在3.0×10-8～1.0×10-4 mol/L的范围内对汞离子呈能斯特响应,响应斜率为31.2 mV/dec,检出限为2.0×10-8 mol/L.该电极对大多数常见的金属离子具有良好的选择性,并可作为指示电极用于电位滴定.     

以单环有机锡配合物为载体的水杨酸根阴离子选择电极的研究

Two new cyclic pentacoordinative organotin(Ⅳ) complexes, 2,4-dihydroxyacetophenone tribenzyltin(HAPTBT) and 2,4-dihydroxyacetophenone triphenyltin(HAPTPT) were synthesized and used as anion ionophore for PVC membrane electrode. The new electrodes exhibit specificity selectivity for salicylate. The electrode based on HAPTBT as a neutral carrier displays a highly potentiometric response to salicylate and an anti-Hofmeister selectivity sequence in the following order: Sal^- ＞ SCN^- ＞ I^- ＞ NO₂^- ＞ Br^- ＞ Cl^- ＞ ClO₄^- ＞ NO₃^- ＞ SO₄^2-. The electrode has the advantages of fast response, stability and reproducibility, simplicity. The response mechanism is discussed in view of UV spectroscopy technique. The results show that there are close relationship between the potentiometric response characteristics and structure of organotin(Ⅳ) complexes. The electrode was applied to medicine analysis with satisfactory results.     

Pentacoordinate organotin complexes as neutral carriers for salicylate-selective PVC membrane electrodes

Selectivity properties are established for three new electrodes prepared by incorporating three pentacoordinate organotin(IV) complexes, mono(2,4-pentanedionato-o,o') tri(phenylmethyl)tin (DMTBS), mono(benzoylacetonato-o,o') tri(phenylmethyl)tin (MPTBS) and mono(dibenzoylmethanato-o,o') tri(phenylmethyl)tin (DPTBS) into plasticized PVC membranes. These electrodes exhibit linear response to salicylate and an anti-Hofmeister selectivity pattern with high specificity for salicylate over many common anions. The results show that the potentiometric response characteristics are related to the structure of organic ligands. The detection limit and the slope of the electrodes based on these pentacoordinate organotin complexes exhibit a tendency to decrease as the substituent in organic ligands changes from a methyl group to a phenyl group. Electrodes prepared with DMTBS have the best detection limit and the highest degree of selectivity and sensitivity for salicylate. The response mechanism is also investigated by use of a.c. impedance and i.r. spectroscopic techniques.     

Effects of ion-carrier substituents on the potentiometric-response characteristics in anion-selective membrane electrodes based on iron porphyrins.

The potentiometric response characteristics with respect to salicylate anion of several membrane electrodes based on iron(III) tetraphenylporphyrin chloride (FeTPPCl) and derivatives with electrophilic and nucleophilic substituents, incorporated into plasticized polyvinylchloride (PVC) membranes were investigated. Complexes tetraphenyl porphyrin iron(III) chloride (FeTPPCl; A), tetrakis (4-methoxyphenyl) porphyrin iron(III) chloride (Fe(TOCH3PP)Cl; B), tetrakis (2,6-dichlorophenyl) porphyrin iron(III) chloride (Fe(TDClPP)Cl; C), tetrakis (4-nitrophenyl) porphyrin iron(III) chloride (Fe(TNO2PP)Cl; D), and tetrakis (pentafluorophenyl) porphyrin iron(III) chloride (Fe(TPFPP)Cl; E) were used as anion carriers in the membrane electrodes. The sensitivity, working range, detection limit, response mechanism, and selectivity of the membrane sensor toward interference shows a considerable dependence on the type of carrier substituent and the pH value of the sample solution. Potentiometric investigations in solutions of various pH show that the carrier complex containing fluoro substituents (E), which have very strong electron-accepting properties and a high ability to form hydrogen bonds, is capable of serving as a positively charged ionophore. Some other ionophores are capable of serving as both charged and neutral carriers under different conditions. The electrodes prepared in this work show super-Nernstian slopes with respect to salicylate concentration, which tend to a Nernstian response (slope near to -59 mV decade-1) upon an increase of the pH of the test solution. The results of UV/Vis absorption spectroscopy are used for interpretation of the formation of an oxene complex between salicylate and iron porphyrins.     

Potentiometric membrane sensors for the selective determination of pyridoxine hydrochloride (vitamin B6) in some pharmaceutical formulations

The construction and general performance characteristics of two novel potentiometric PVC membrane sensors responsive to the pyridoxine hydrochloride known as vitamin B6 (VB6) are described. These sensors are based on the use of the ion-association complexes of the pyridoxine cation with phosphomolybdate, and phosphotungstate counter anions as ion pair in a plasticized PVC matrix. The electrodes show a stable, near-Nernstian response for 6x10(-5)-1x10(-2) M VB6 at 25 degrees C over the pH range 2-4 with a cationic slope of 54.0+/-0.5 and 54.5+/-0.4 per concentration decade for pyridoxine-phosphomolybdate and pyridoxine-phosphotungstate respectively. The two electrodes have the same lower detection limit (4x10(-5) M) and the response times are 45-60 and 30-45 s in the same order for both. Selectivity coefficients for VB6 relative to a number of interfering substances were investigated. There is negligible interference from many cations, some vitamins and pharmaceutical excipients. Direct potentiometric determination of 15-2000 microg/ml pyridoxine shows an average recovery of 98.0% and 99.0% with relative standard deviation 1.5% and 1.2% at 100.0 microg/ml for pyridoxine-phosphomolybdate and pyridoxine-phosphotungstate electrodes, respectively. The determination of VB6 in some pharmaceutical preparations using the proposed electrodes gave an average recovery of 98.0 and 99.0% of the nominal value and a mean standard deviation of 1.1% and 0.9% (n=10) for pyridoxine-phosphomolybdate and pyridoxine-phosphotungstate electrodes, respectively. The results compare favorably with data obtained by the British Pharmacopoeia method.     

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.     

Phenothiazine Drug Poly(vinyl chloride) Matrix Membrane Electrodes and Their Use in Pharmaceutical Analysis

The construction and performance characteristics of ion-selective membrane electrodes for phenothiazine drugs based on their ion-pair complexes with tetraphenylborate and dinonylnaphthalenesulfonate in a poly(vinyl chloride) matrix are described. The electrodes show a near-Nernstian response over various ranges depending on the nature of the phenothiazine drug. The selectivity of these electrodes to a number of amino acids, alkaloids, neurotransmitters, quaternary ammonium compounds, and other drugs or pharmaceutical excipients is reported. The standard additions method and potentiometric titrations are used to determine the phenothiazine drugs in pharmaceutical preparations with satisfactory results.     

Salicylate-Selective PVC Membrane Electrodes Based on Tribenzyltin(IV) Phenolates as Neutral Carriers

ABSTRACT

A series of tribenzyltin(IV) phenolates were synthesized and used as anion ionophores for PVC membrane electrodes; these novel electrodes exhibit a linear response towards salicylate and an anti-Hofmeister selectivity pattern with high specificity for salicylate over many common anions. The results show that the behavior of the electrodes is considerably influenced by the structures of the carriers and the experimental conditions. Electrodes based on tribenzyltin(IV) p-nitrophenolate possess the best potentiometnc response characteristics and show a linear log[Sal^?] vs. EMF response over the concentration range 0.1–3.98×10^?6 mol.L^?1 in phosphate buffer solutions of pH 5.38 with a detection limit of 2.51×10^?6 mol.L^?1 and a slope of -57.05 mV per decade. The response mechanism was also investigated by use of a.c. impedance and anion transport across liquid membranes. The electrodes were applied to the determination of salicylate in urine samples with satisfactory results.     

Coated film electrodes

Summary The construction of coated-film electrodes is described. It is shown that they are miniaturizable, inexpensive, simple sensors for various cations and anions. They are similar to the coated-wire electrodes, but instead of a metal wire an extremely thin conductive metal layer manufactured in thin-film technology is used. Potassium and sodium electrodes studied so far show excellent electrode properties, i. e. near Nernst response over a wide concentration range, sometimes better than commercial ion-selective electrodes. Two film electrodes are used to develop a low cost sensor for the determination of the activity of ions in a simple way by potentiometric difference measurement; this solid-state sensor can be applied to biomedical measurements, especially for blood analysis.

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Filmelektroden

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Dedicated to Prof. Dr. G. Tölg on the occasion of his 60th birthday     

Hydrophobic ionic liquids in plasticized membranes of ion-selective eletctrodes

Ionic liquids with substituted imidazole, pyridine, and pyrrolidine cations and hydrophobic anions are studied as ionophores of PVC membranes of ion-selective electrodes plasticized with 2-nitrophenyloctyl ether. These membranes show a response to hydrophobic organic cations. In solutions of cationic surfactants, the slope of the electrode function is close to the theoretical one and the limit of detection does not exceed n × 10⁻⁶ M. Ion-selective electrodes for anions are developed using a trioctylmethylammonium salicylate ionic liquid. The electrode on its basis shows a stable potentiometric response to the salicylate anion in a wide range of concentrations and is characterized by good selectivity in the presence of foreign anions.     

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.