Preparation of a new solid state fluoride ion selective electrode and application

A new solid state fluoride ion selective electrode composed of 70% Ag₂S, 10% Cu₂S and 20% CaF₂ has been developed. An analytically useful potential change occurred, from 1 × 10⁻⁶ to 1 × 10⁻¹ M fluoride ion. The slope of the linear portion (1 × 10⁻¹-1 × 10⁻⁵ M) was about 26 ± 2 mV/10-fold concentration changes in fluoride. It was found that pH change between 1 and 8 had no effect on the potential of the electrode. There was no interference of most common cations such as K^+, Na⁺, Ca²⁺ and Mg²⁺ and anions such as Cl⁻, NO₃⁻, SO₄²⁻ and PO₄³⁻. The lifetime of the electrode was more than 2 years, when used at least 4-5 times a day, and the response time was about 60 s.The measurements were made at constant ionic strength (0.1 M NaNO₃) and at room temperature. This electrode has been used for the determination of fluoride ion in Ankara city tap water and in bottled spring water using standard addition method. The validation of the electrode has been made with a commercial fluoride ion selective electrode (Orion) and high consistency was obtained.     

Preparation and application of a new glucose sensor based on iodide ion selective electrode

An electrode for glucose has been prepared by using an iodide selective electrode with the glucose oxidase enzyme. The iodide selective electrode used was prepared from 10% TDMAI and PVC according our previous study. The enzyme was immobilized on the iodide electrode by holding it at pH 7 phosphate buffer for 10 min at room temperature. The H₂O₂ formed from the reaction of glucose was determined from the decrease of iodide concentration that was present in the reaction cell. The iodide concentration was followed from the change of potential of iodide selective electrode. The potential change was linear in the 4×10⁻⁴ to 4×10⁻³ M glucose concentration (75-650 mg glucose/100ml blood) range. The slope of the linear portion was about 79 mV per decade change in glucose concentration. Glucose contents of some blood samples were determined with the new electrode and consistency was obtained with a colorimetric method. The effects of pH, iodide concentration, the amount of enzyme immobilized and the operating temperature were studied. No interference of ascorbic acid, uric acid, iron(III) and Cu(II) was observed. Since the iodide electrode used was not an AgI-Ag₂S electrode, there was no interference of common ions such as chloride present in biological fluids. The slope of the electrode did not change for about 65 days when used 3 times a day.     

Fabrication of new solid state phosphate selective electrodes for environmental monitoring

A highly selective and sensitive phosphate sensor has been fabricated by constructing a crystal disk consisting of variable mixtures of aluminium powder (Al), aluminium phosphate (AlPO₄) and powdered copper (Cu). The membrane sensor exhibits linear potential response in the concentration range of 1.0 × 10⁻¹ to 1.0 × 10⁻⁶ mol L⁻¹. The proposed sensor also exhibits a fast response time of <60 s. Its detection limit is lower than 1.0 × 10⁻⁶ mol L⁻¹. The electrode has a long lifetime and can be stored in air when not in use. The selectivity of the sensor with respect to other common ions is excellent.     

氧氟沙星选择性电极的改进研究及应用

分别以氧氟沙星-磷钼酸与氧氟沙星-四苯硼钠离子缔合物作为电活性物质制备氧氟沙星选择性电极,并系统研究和比较了这两种电极的响应性能。实验表明以磷钼酸-氧氟沙星离子对作为电活性物质,以四苯硼钠作添加剂所制备的氧氟沙星电极呈现了良好的Nernst响应,且其选择性明显提高。用该电极测定了药物中的氧氟沙星。     

涂碳型PVC膜培氟沙星选择电极的研制

报道一种以盐酸培氟沙星与溴汞酸盐生成的分子缔合物为电活性物质的新型涂碳PVC膜培氟沙星选择电极。在pH 1 .5～ 4.5范围内 ,电极对培氟沙星的Nernst响应范围为 1 .0× 1 0 - 2 ～ 5 .0× 1 0 - 5mol/L ,检测限为 4.2× 1 0 - 6mol/L。方法的平均回收率为 98.5 % ,RSD为 1 .0 %     

Preparation and application of selenite ion selective electrode

A new selenite ion selective electrode using 4,6-dibromopiaselenole as active material, PVC as membrane matrix and dibutyl phthalate as plasticizer has been developed. An analytically useful potential change occurs from about 10(-6)-10(-1)M Se(IV), and the slope of the linear portion is -23.6 mV/10-fold change in Se(IV) concentration at a temperature of 21 degrees . The electrode shows fairly good selectivity for selenite ion over other anions and has been used for the successful determination of total selenium in human hair.     

Side effects in measurements of selectivity coefficients of solid state ion selective electrodes

The influence of various factors such as solubility, the oxidation of the membrane, and the contamination of the solution, on the experimental values of the selectivity coefficients of solid state sulphide ion selective electrodes is discussed. A new method for the evaluation of very small selectivity coefficients, based on the addition of reagents forming complexes or insoluble salts with the main ion, is proposed. By means of this method, selectivity coefficients for silver, copper, cadmium and lead ion selective electrodes have been determined, which are in far better agreement with thermodynamic values than those described in the literature.     

Preparation and properties of solid state selenite ion selective electrodes and their applications

A new selenite ion selective electrode using solid salts of Ag(2)Se and Cu(2)S has been developed. Detailed information is provided concerning the composition, working pH and conditioning of the electrode. The change of potential with concentration is found to be linear in the range of 10(-5)-10(-2) M, the slope of the linear portion is 28 mV/10-fold change in selenite concentration. The effect of other ions on selenite response is evaluated and selenium content of anodic slime is determined.     

茜素S选择电极的研制和应用

本文报道了茜素S电极的研制和应用。比较了季铵盐、季鏻盐、碱性染料和邻二氮菲金属配合盐作为活性物质、各种介体溶剂以及活性物质在膜相中的含量对电极性能的影响。以三辛基甲基氯化铵制成的PVC膜型电极对茜素S在2×10~(-4)～5×10~(-7)M浓度范围内呈Nernstian响应,检测下限为2×10~(-7)M。测定了一些阴离子的选择系数,ClO_4~-,CNS~-,I~-以及能与茜素S配合的金属离子有明显干扰。报道了以茜素S电极为指示电极,用EDTA和茜素S为滴定剂滴定钪和稀土的情况。以茜素8电位滴定钪及钴-钐合金中的钐,都获得良好的结果。     

以锑电极作参比电极测定废水中硫化物

提出了以锑电极作为参比电极与Ag2 S电极组成无液接测量电池测定废水中硫化物的新方法。并研究了电极的性能 ,测定条件及干扰物质的影响。方法的线性范围 1 .0× 1 0 - 2 mol/L～ 5 .0× 1 0 - 7mol/L[S2 - ],回收率为 99%～1 0 3%     

双氯芬酸钠在多壁碳纳米管修饰电极上的电化学行为及其应用

应用循环伏安法和线性扫描伏安法研究了双氯芬酸钠在多壁碳纳米管修饰电极上的电化学行为,建立了一种直接测定双氯芬酸钠的电分析方法.在0.1 mol/L HClO4溶液中,双氯芬酸钠的氧化峰电位在0.38 V(vs Ag/AgCl),峰电流与浓度在2.0×10-7 mol/L～7.0 × 10-6 mol/L范围内呈线性关系,开路富集3 min后检出限为9.0×10-8 mol/L.5×10-6 mol/L双氯芬酸钠溶液平行测定10次的相对标准偏差(RSD)为4.5%.已用于扶他林片剂中双氯芬酸钠的测定.     

A selective membrane electrode for iodide ion based on a thiopyrilium ion derivative as a new ionophore

A highly selective electrode for iodide ion based on a thiopyrilium derivative as an excellent ionophore is described. At pH 5.5-8.0, the electrode responds to iodide ion in a linear range from 1.0×10⁻¹ to 8.0×10⁻⁷ M with a slope of 60.2 mV per decade, and a detection limit of 2.0×10⁻⁷ M. Selectivity coefficients determined with the match potential method (MPM) indicate that the interference from inorganic and organic anions is very small. The proposed sensor shows a fast response time of approximately 15 s. It was applied as an indicator electrode in titration of iodide with Ag⁺.     

盐酸依匹斯汀PVC膜电极的研制及应用

以四苯硼酸钠与盐酸依匹斯汀生成的离子缔合物为电活性物质,研制了盐酸依匹斯汀PVC膜选择性电极。在pH 5的HCl-NaOH溶液中,电极的线性范围为6.3×10-7~1.0×10-1mol/L,斜率为49 mV/pC(10℃),检出限为1.89×10-7mol/L。应用此电极测定药物中盐酸依匹斯汀含量,RSD3%,回收率为97.5%~100.2%。     

Direct determination of benzylnitriles using the cyanide ion selective electrode

The response characteristics of the solid state cyanide ion selective electrode towards some benzylnitriles are investigated. In 10M KOH solution, the electrode exhibits nearly Nernstian response over the concentration range of 10^–2 to 10^–4 M of various substituted benzylnitriles with an anionic slope of 53–59 mV/concentration decade. The response time varies from 10 to 20 min depending on both the nature of the substituent group and the concentration of the nitrile compound. Direct potentiometric measurement of some nitrile compounds at the concentration level of 0.01 to 1 mg/ml shows an average recovery of 98.2% and a mean standard deviation of 2.3%. Many nitrogen functional groups do not interfere.     

吡虫啉分子印迹聚合物的合成及固相萃取性能研究

采用分子印迹技术,以丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,在甲醇溶液中合成了吡虫啉分子印迹聚合物,研究了聚合物的吸附性和选择性,用聚合物固相萃取大蒜中吡虫啉残留量。结果表明,聚合物通过离子键和氢键对模板分子产生了印迹效应,对吡虫啉具有明显的选择性。通过优化淋洗和洗脱条件,对大蒜中的残留吡虫啉富集。     

High pressure in solid state chemistry: Combined experimental and modeling approaches for assessing and predicting properties

The thermodynamic pressure parameter has been thoroughly used with mastership by Gérard Demazeau throughout his rich career in solid state chemistry and materials sciences and more recently in biosciences. After a review of such works, focus is made in this topical article on his contribution together with his team in the field of hard materials based on light elements B, C, N with a proposition of a new ultra-hard carbon nitride C₂N on one hand and on the structural transformations under high pressures of perovskite into postperovskite with a change of dimensionality from 3D to 2D and related oxides, regarding the arrangement of octahedra, on the other hand. Investigation and concepts first arising from experimental observables are shown to be aided and accelerated via first principles calculations of energy and energy-related quantities.     

新型平板碳电极的研制与应用

研制了一种新型平板碳电极,用K3Fe(CN)6对电极的性能进行了简单的研究。将该电极用于神经递质多巴胺(DA)的测定,发现在pH 7.0的磷酸盐缓冲介质(PBS)中,多巴胺在该电极上产生一灵敏的氧化峰,峰电流与DA浓度在6.0×10-8~1.0×10-3mol/L范围内呈良好的线性关系,检出限(3σ)为2.0×10-8mol/L。方法可用于人工合成样品的分析。     

基于Ag/AgCl丝双涂膜司帕沙星选择电极的研制与应用

以Ag/AgCl丝为基体依次外涂含0.1 mol/L KCl的琼脂凝胶膜及含四苯硼-司帕沙星缔合物的PVC膜,制备了一种双涂膜司帕沙星选择电极。采用正交设计法,研究了离子缔合物的种类、活性物在膜中的浓度及增塑剂三因素对电极的影响。电极的线性范围为1.0×10-5~1.0×10-3mol/L,检出限为2.4×10-6mol/L,斜率为28.8 mV/decade(16℃),可直接用于司帕沙星片剂的含量测定,回收率为99.6%~101.1%,结果与文献法一致。