溶胶-凝胶膜修饰的碘离子选择性电极

用溶胶-凝胶包埋硝酸银制备了碘离子选择性电极.电极对I-离子在10-1~10-7mol/L浓度范围内呈Nernst响应,斜率为58.321 mV/pI-,检测下限为4.6×10-8mol/L,回收率为97.4%~103.2%.     

溶胶-凝胶膜修饰碳酸根离子选择电极的研究

利用溶胶-凝胶技术包埋电活性物质,制备溶胶-凝胶膜修饰的碳酸根离子选择电极。探索了Sol-Gel膜修饰CO32-选择电极的制备方法、测试条件及共存物的影响。电极的线性范围1.0×10-1~1.0×10-5mol/L,相关系数R2=0.993,检测限8.9×10-6mol/L,响应斜率22.1 mV/pCO3。电极稳定性和重现性良好,用于实际样品测定,回收率95.9%~99.0%。     

溶胶-凝胶基质修饰的镉离子选择性电极

一种以CdS为活性物质,用溶胶 凝胶技术制作的新型镉离子选择性电极。电极的斜率为29mV/decade,线性范围为1.0×10-1～6.0×10-5mol/L,检测下限为4.5×10-5mol/L,适宜的pH3.2～5.9,并对回收率进行了测定。     

溶胶-凝胶法修饰的一次性氯离子选择性电极的研究

溶胶-凝胶法(sol-gel)对固定试剂的种类和数量具有可调性,又具有保持性能稳定的潜在优势;一些小分子离子可以自由进出sol-gel的孔径,使得sol-gel基质内外浓度相等,因而可制备化学电极。本文通过正硅酸乙酯[TEOS]在适宜的酸催化下,水解制得电极材料,采用溶胶．凝胶掺杂技术,成功地修饰了新型氯离子选择性电极,这种电极的线性范围和AgCl-AgS2固态膜电极、     

以聚氯乙烯-双硫腙-铜络合物为载体的长寿命硫氰酸根离子选择电极

报道了以PVG-双硫腙（DTZ）-Cu（Ⅱ）,PVC-DTZ-Cu（Ⅰ）为载体制备了性能良好的SCN-离子电极,其选择性次序为SCN~-》ClO_4~->Sal~-》NO_3~-~Cl~->PO_4~(2-)。16℃时,膜组成为PVC－DTZ-Cu（Ⅰ）：PVC：邻硝基苯基辛醚（o-NPOE）＝12∶22∶66的SCN~-离子电极,在0．02mol/LHCl体系中,在1×10~(-2)~5×10~(－6)mol/LSCN~-浓度范围呈能斯特响应,斜率为58±2mV/dec,检测限为2×10~(-6)mol/L;膜组成为PVC-DTZ-Cu（Ⅱ）∶PVC∶o-NPOE∶四苯硼酸钾（KTPB）为8∶22∶55∶15的电极,在0．01mol/LHAc-NaAc缓冲体系中,在10~(-2)~2×10~(-6)mol/LSCN~-浓度范围呈线性响应,斜率为54∶1mV/dec,检测限为8×10~(－7)mol/L.研究了阴离子与载体作用的机理,表明SCN~-与载体中铜原子直接作用。电极应用于废水中SCN~-的测定,结果令人满意。     

溶胶-凝胶基质修饰的碘离子选择电极

研制了一种用溶胶 -凝胶作为基质 ,进行化学修饰的碘离子选择电极 ,并对溶胶 -凝胶包埋活性敏感物质的条件和电极响应机理进行了优化和探讨 ;电极Nernst响应范围为1.0×10 -1～5.0×10 -7mol/L,斜率为58.0mV/pc ,检出限为1.0×10-7 mol/L;电极制作简单 ,成本低廉 ,易于成批生产和微型化 ,具有可在严酷条件下使用的特点 ;电极用于样品分析 ,结果令人满意     

溶胶凝胶溴离子选择电极的研制与应用

报道了一种以溶胶凝胶为载体的溴离子选择电极。电极信号响应线性范围为1 .0× 1 0 - 1～ 1 .0× 1 0 - 5mol/L,斜率为 5 7m V/pc;检出限为 2 .5× 1 0 - 6 mol/L。该电极响应快 ,体积小 ,稳定性和重现性好。电极用作测定溴离子浓度 ,结果令人满意     

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.     

溶胶-凝胶包埋法制备银离子选择电极的研究

研制了一种用溶胶 凝胶技术包埋电活性物质的银离子选择电极。研究了包埋过程的变量参数及电极的响应机理。电极Nernst响应范围为 1.0× 10 - 1～ 1.0× 10 - 5mol·L- 1,斜率为5 5 .5mV·pc- 1,检出限为 3.1× 10 - 6mol·L- 1。该电极响应快 ,体积小 ,制作简单 ,使用方便 ,具有坚固耐磨 ,可在严酷条件下使用的特点。此研究对进一步研制溶胶 凝胶ISFET化学传感器和生物传感器具有探索意义     

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.     

直接电位法测定工业废水中的硫氰酸根离子

用直接电位法测定了统扑净生产废水和印染厂排放废水中硫氰酸根的浓度。在温度为 1 6℃ ,浓度为 0 .0 2 mol/L HCl的体系中 ,以功能高分子 PVC-双硫腙 -铜 ( I)载体的 SCN-离子电极在 SCN-离子浓度为 1 .0× 1 0 -2 ～ 5× 1 0 -6mol/L时呈能斯特响应 ,斜率为 58± 2 m V/dec,检出限为 2 .0× 1 0 -6mol/L。电极的选择性次序为 :SCN->>Cl O4 -～Sal->>Cl->NO3 ->HPO4 2 ->SO4 2     

二氧化钛溶胶凝胶膜修饰的维生素B6电极

制备了一种以硅钨酸为定域体试剂,用溶胶-凝胶技术制作的新型维生素B6电极,详尽讨论了电极性能的影响因素。电极斜率为58.0 mV/dec,线性范围为1.0×10-2～4.0×10-6mol/L,检测限为2.5×10-6mol/L。该电极易于批量生产和微型化,用于样品分析,结果令人满意。     

Study of beta-cyclodextrin/fluorinated trimethyl ammonium bromide surfactant inclusion complex by fluorinated surfactant ion selective electrode

The construction and performance of a liquid membrane electrode responsive to N-(1,1,2,2-tetrahydroperfluorooctyl)-N,N,N-trimethylammonium bromide (FTABr) and its use for the study of β-cyclodextrin/fluorinated surfactant inclusion complex is described. The electrode is based on the use of tetrahydroperfluorooctyltrimethylammonium-tetraphenylborate ion pair as electro active material in polyvinyl chloride (PVC) matrix plasticized using 2-Nitrophenyl octyl ether (NPOE). The electrode exhibits a fast, stable, reproducible and “Nernstian” response (59 ± 2 mV) for FTABr over the concentration range of 10⁻⁵ to 2 × 10⁻³ mol L⁻¹ at 298 K. The lowest detection limit is 2 × 10⁻⁶ mol L⁻¹ and the response time is around 20-30 s. The validity of the electrode, for detection of fluorinated surfactant ions and hence to carry out electrochemical measurements to study micellization of fluorinated surfactant, is verified by comparing the critical micelle concentration (cmc) value of FTABr obtained by using the electrode, with that obtained by surface tension measurements. Association constant K for β-cyclodextrin/FTABr complex is evaluated from the potentiometric measurements carried out using this electrode and is observed to be ∼1.26 × 10⁵. The results suggest that β-cyclodextrin forms an equimolar association complex with the FTA⁺ surfactant ion.     

Measuring quaternary ammonium cleaning agents with ion selective electrodes

Data for coated-wire, ion selective electrodes (ISEs) are presented for cationic surfactant ions found in common cleaners including benzyldimethyltetradecylammonium, benzyldimethyldodecylammonium, and benzyldimethylhexadecylammonium. The ion exchangers dinonylnaphthalene sulfonic acid, tetraphenyborate, and tetrakis(4-chlorophenyl)borate are examined, showing dinonylnaphthalene sulfonic acid to be the favored species. The ISEs exhibit approximately Nernstian behavior down to the 10⁻⁶ M limit of detection with lifetimes in excess of 50 days when used continuously, and a shelf life of over 100 days. Reaching the upper detection limit at the critical micelle concentration requires use of polymeric-membrane reference electrodes including a new membrane cocktail, which allow response measurements of an order of magnitude higher than the traditional fritted-glass reference electrode. The surfactant ISEs show excellent selectivity over the common metal ions Na⁺, K⁺, Mg²⁺, Ca²⁺, and Cu²⁺ with selectivity coefficients less than 10^−5.3. The ISEs are also selective over the lower molecular weight quaternary ammonium ions tetradecyltrimethylammonium, dodecyltrimethylammonium, benzyldimethyl(2-hydroxyethyl)ammonium, and tetrabutylammonium with selectivity coefficients ranging from 10^−1.7 to 10^−5.5. Use of a single electrode to determine accurately the total cationic surfactant concentration in common cleaning solutions is accomplished with information about concentration dependent interferences and a modified Nikolsky–Eisenman model. Finally, quaternary ammonium surfactants have a deleterious effect on the measurements of pH and common ions like K⁺, Mg²⁺ and Ca²⁺ with polymeric ISEs. This makes it critical to include surfactant electrodes in a detector array when cleaning agents are present.     

Lead-sensitive membrane electrode based on chelating ion exchanger

A new selective membrane electrode for the measurement of lead activities is proposed. The preparation of active components of the membrane is described. The ready made electrode insert was used in which the PVC membrane was replaced by the prepared membrane. Experimental results document the emf response of profile, the selectivity, the detection limit and the effect of the sample media. The prepared electrode was applied for the measurement of the lead concentration in water samples. Activated alumina micro-column was used for the pre-concentration of lead in the analyzed water samples. The obtained results were compared with those determined by atomic absorption spectrometry.     

Chromium(III) ion selective electrode based on glyoxal bis(2-hydroxyanil)

A poly(vinyl chloride) membrane based on glyoxal bis(2-hydroxyanil) as membrane carrier was prepared and investigated as a Cr(III)-selective electrode. The electrode has a linear dynamic range of 3.0×10⁻⁶-1.0×10⁻² mol l⁻¹, with a Nernstian slope of 19.8±0.5 mV per decade and a detection limit of 6.3×10⁻⁷ mol l⁻¹. It has a fast response time of <20 s and can be used for at least 3 months without any considerable divergence in potential. The proposed electrode revealed good sensitivities for Cr(III) over a wide variety of metal ions and could be used in a pH range of 2.7-6.5. Above all, the membrane sensor has been used very successfully for the analysis of some food materials and alloys for the determination of Cr(III) ion.     

Determination of trace thiocyanate with nano-silver coated multi-walled carbon nanotubes modified glassy carbon electrode

Novel nano-silver coated multi-walled carbon nanotube composites were prepared and used to fabricate a modified electrode. The application of the nano-silver coated multi-walled carbon nanotube composites modified electrode for determination of trace thiocyanate is demonstrated for the first time. The influence of substrate, pH and interference of coexisting substances was investigated for response properties of the electrode. There was a linear relationship at the range 2.5 × 10⁻⁹ to 5 × 10⁻⁸ mol L⁻¹ and 5 × 10⁻⁸ to 1 × 10⁻⁶ mol L⁻¹ of thiocyanate with the decrement of anodic DPV peak currents. The limit of detection was 1 × 10⁻⁹ mol L⁻¹(S/N = 3). The constructed electrode showed excellent reproducibility and stability. Actual urine and saliva samples of smoker and non-smoker were analyzed and satisfactory results were obtained. This method provides a new way to construct any electrode for biological and environmental analysis.