四苯硼酸盐PVC膜铯离子选择性电极的研究

四苯硼酸盐为活性物质的PVC膜对金属离子的选择性同溶剂的性质相关。本文考察了以邻硝基苯辛醚(o-NPOE)、邻苯二甲酸二正辛酯(DOP)及癸二酸二丁酯(DBS)为溶剂的四苯硼酸盐PVC膜对金属离子的选择性,比较了四苯硼钠(NaTPB)、四苯硼钾(KTPB)、四苯硼铷(RbTPB)及四苯硼铯(CsTPB)等几种碱金属的四苯硼酸盐为活性物质的膜的电化学性能,研制了以o—NPOE为溶剂,NaTPB为活性物质     

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]。     

新型全固态丁卡因选择电极的研究

改进了以脲醛树脂为框架以KCl为活性物质的全固态Ag/AgCl参比电极。以改进后的Ag/AgCl电极为基体,以丁卡因 四苯硼酸根离子缔合物为活性物质,研制了一种新型全固态丁卡因选择性电极,并对此电极的性质进行了研究。该电极的适用范围为pH3.0～6.5,线性范围为5×10-5～5×10-2mol/L,检测下限为2.2×10-5mol/L。该电极能用于盐酸丁卡因的含量测定。     

用于生理研究的中性载体锂离子选择性液膜微电极的研制

本文报道一个以中性载体ETH1810为活性材料的锂离子选择性液膜微电极,对钠和钾离子的选择性系数分别为-2.0和-2.4(对数值),端径为1μm,内阻为1.2×10~(10)Ω,可用于细胞内外锂离子活度的测定。     

钠离子选择性双管微电极及在生物医学中的适用性

钠离子选择性电极可用来测量体液及体表面钠离子进行疾病的诊断及监测,钠玻璃微电极巳用于研究心肌及神经细胞内钠离子的生理、病理作用^[1-4]。液膜型钠离子选择性微电极制作方便,内阻较小,亦有报导^[5]。本工作采用N,N′-双二苄基-3,6-二氧杂辛二酰胺为活性物质,癸二酸二丁酯为增塑剂研制了一种PVC膜钠离子选择性双管复合型微电极。探讨了该微电极在生物医学测量中的适用性。该微电极性能良好,对K⁺的选择性同文献报道的同类电极^[6]相近,而抗Ca²⁺、Mg²⁺等离子的干扰能力有较大的提高。     

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%。     

铊(I)离子选择性电极的研制及性能测定

研制铊(Ⅰ)离子选择性电极以沉淀膜为多,但性能不理想。最近有报道以双冠醚为活性物质的 PVC 膜铊(Ⅰ)电极性能较好。本文报道了一些以冠醚材料,四苯硼化铊为活性物质的 PVC 膜铊(Ⅰ)电极的研制,其中以4-甲基-二苯并-30-C-10和四苯硼化铊混合物者最好,响应快,再现性好,在1×10~(-2)—5×10~(-6)M 范围内符合 Nernst 关系。从测得的各项电极性能指标看,与双冠醚电极相同或稍优。     

中性载体钠离子选择性微电极的研制

研制了以中性载体(ETH1097)为电活性物质的PVC钠离子选择性微电极。电极尖端直径小至2.5μm,线性响应范围10~(-3)-5×10~(-1)MNa~+,检测下限1.2×10~(-4)M,斜率为58.2mV(25℃).对K~+,Mg~(2+)、Ca~(2+)的选择性系数分别为0.050,6.5×10~(-4)及5.5×10~(-3)。该微电极特别适用于细胞内钠离子活度的测量。实验探讨和比较了癸二酸二丁酯(DBS)和邻苯二甲酸二正辛酯(DOP)为增塑剂的钠微电极的性能。研究了四苯硼钠(NaTPB)和硫氰酸钠(NaSCN)加入膜中后,电极性能的变化。为用于细胞内及临床微量试样中钠离子活度测量,电极采用DBS为增塑剂,并加入适量的NaTPB较宜。     

测定盐酸西布曲明的电位传感器的研制与应用

以四苯硼酸钠与盐酸西布曲明生成的离子缔合物为电活性物质,研制了盐酸西布曲明传感器。试验表明:盐酸西布曲明聚氯乙烯(PVC)膜传感器对盐酸西布曲明具有良好的选择性和电位响应特性。在pH 5的溶液中,电极电位呈现近能斯特响应,线性范围为1.0×10-6～1.0×10-1mol.L-1,斜率为50 mV.pc-1(26℃),检出限(3S/N)为5.62×10-7mol.L-1。将电极用于药物中盐酸西布曲明含量的测定,测得回收率为97.3%～100.2%,测定值的相对标准偏差(n=5)均小于2%。     

LiFePO4单颗粒电化学本征性能的快速精确评测

通常需要将电活性材料与导电剂、粘接剂等辅助物质混合后,制成复合电极来评测材料的电化学性能,但辅助物质和复合电极结构可能影响评测结果的准确性. 由于单颗粒微电极可选取单一颗粒进行测试,无需加入添加剂材料,因此,采用单颗粒微电极评测材料性能可以得到材料的本征性能. 同时,单颗粒微电极还可以实现对材料的快速、精确评测. 本文利用单颗粒微电极方法测试了球形LiFePO4颗粒的循环伏安特性、循环稳定性和动力学性能. 结果表明,单颗粒微电极可以20 mV?s-1的速率快速扫描、精确测试,测得锂离子在该颗粒中的扩散系数约为2.4 ~ 3.2?10-11 cm2?s-1,电化学反应的控制步骤为锂离子的固相扩散控制. 另外,LiFePO4颗粒在该单颗粒微电极构成的电池中表现出良好的循环稳定性. 这些显示了单颗粒微电极在电极材料特性研究中的可行性.     

A New Approach for Decreasing the Detection Limit of Gentamicin Ion‐selective Electrodes by Incorporation of Multiwall Carbon Nanotubes (MWCNTs)/Lipophilic Anionic Additives

Two novel carbon paste electrodes based on gentamicin‐reineckate (GNS‐RN)/multiwall carbon nanotubes (MWCNTs)/sodium tetraphenyl borate (NaTPB) or potassium tetraphenylborate (KTPB) for potentiometric determination of gentamicin sulfate were constructed. Our endeavors of lowering the detection limit for gentamicin ion‐selective electrodes were described. The paper focused on gentamicin carbon paste electrodes based on GNS‐RN as electroactive material, o ‐nitrophenyloctyl ether (o ‐NPOE) as plasticizer and incorporation of MWCNTs and lipophilic anionic additives (NaTPB and KTPB) which lower the detection limit of the electrodes showing best results for determination of gentamicin ion. The characteristics of the electrodes, GNS‐RN+NaTPB+MWCNTs (sensor 1) and GNS‐RN+KTPB+ MWCNTs (sensor 2), were measured, showing favorable features as they provided measurements of the potential with near‐Nernstian slopes of 29.6±0.3 and 29.1±0.3 mV/decade over the concentration range of 1.0×10⁻⁶–1.0×10⁻² mol L⁻¹ and pH ranges 3.0–8.2 and 3.0–8.0 in short response times (6.5 sec). Importantly, the electrodes had low detection limits of 3.0×10⁻⁷and 3.4×10⁻⁷ mol L⁻¹ for the two sensors, respectively. The sensors showed high selectivity for gentamicin ion with respect to a large number of interfering species. The electrodes were successfully applied for the potentiometric determination of GNS ions in pure state, pharmaceutical preparations and human urine with high accuracy and precision. The results of this study were compared with some previously published data using other analytical methods.     

亲脂性盐对中性载体钙离子选择性微电极性能的影响

N,N′-二-(11-(乙氧基羟基)十一烷基)-N,N′-4,5-四甲基-3,6-二(口恶)辛基-1,8-二酰胺(ETH1001)广泛用于制备检测细胞内外钙离子活度的离子选择性微电极。为降低膜电阻和消除被测离子的干扰,多采用四苯硼钠(NaTPB)作为添加剂,但这种电极仍存在一些缺点,曾有报道用其它化合物代替NaTPB作添加剂,但电极选择性并没有提高。     

Copper(II) ion selective electrode based on a newly synthesized Schiff-base chelate

A new Cu (II) ion-selective electrode has been fabricated in poly (vinyl chloride) matrix based on a recently synthesized Schiff-base chelate. The addition of sodium tetraphenylborate (NaTPB) and various plasticizers viz. TBP, TEHP, DOS, and CN have been found to substantially improve the performance of the electrode. The membrane of various compositions of the ionophore (I) were investigated and it was found that the best performance was obtained with the membrane having (I): PVC: NaTPB: CN in the ratio 4: 140: 3: 80 (mg). The electrode exhibits a Nernstian response over a wide concentration range (1.9 × 10⁻⁶–1.0 × 10⁻¹ M) with 30.0 mV/decade of concentration between pH 3.0 and 7.5. The response time of the electrode is about 12 s and it can be used over a period of 3 months without any divergence in potential. The potentiometric selectivity coefficient values as determined by fixed interference method indicate excellent selectivity for Cu²⁺ ions over interfering cations. The electrode has also been used successfully in partially non-aqueous media having a 25% (v/v) methanol, ethanol or acetone content without showing any considerable change in the value of slope or working concentration range. The electrode has been used in the potentiometric titration of Cu²⁺ with EDTA.     

Flow injection potentiometric determination of pancuronium bromide in pharmaceutical preparation and urine samples using modified carbon paste electrodes

Carbon paste electrodes for pancuronium bromide was prepared based on ion association complexes of pancuronium bromide with sodium tetraphenylborate (NaTPB) or ammonium reineckate using dibutyl phthalate as solvent mediator and tetradodecylammonium tetrakis-(4-chlorophenyl)borate (ETH 500) as lipophilic additive. The sensors showed a near-Nernstian slope of 28.1 mV concentration decade(-1) at 25°C within the concentration range 6.31×10(-6)-1.00×10(-2) M in case of pancuronium-tetraphenylborate electrode and 26.6 mV concentration decade(-1) in the concentration range 5.66×10(-5)-1.00×10(-2) M in case of pancuronium-reineckate electrode. The sensors were successfully applied for the potentiometric determination of pancuronium bromide in pharmaceutical preparation and biological fluids in batch and flow injection conditions.     

A selective membrane electrode for lanthanum(III) ion based on a hexaaza macrocycle derivative as ionophore.

We have developed a highly La(III)-selective PVC membrane electrode based on a hexaaza macrocycle, 8,16-dimethyl-6,14-diphenyl-2,3,4:10,11,12-dipyridine-1,3,5,9,11,13-hexaazacyclohexadeca-3,5,8,11,13,16-hexaene [Bzo2Me2Pyo2(16)-hexaeneN6] (I) as membrane carrier, dibutylbutyl phosphonate (DBBP) as solvent mediator and sodium tetraphenylborate (NaTPB) as lipophilic additive. The best performance was given by the membrane of macrocycle I having a composition 10:260:5:120 (I:DBBP:NaTPB:PVC). The electrode exhibits a Nernstian response to La(III) ion in the concentration range 1.0x10(-1)-7.94x10(-7) M with a slope of 19.8+/-0.2 mV/decade of concentration and a detection limit of 5.62x10(-7) M. The response time of the sensor is 12 s and it can be used over a period of 4 months with good reproducibility. The electrode works well over a pH range of 2.5-10.0 and in partially non-aqueous medium with up to 30% organic content. The sensor was also used as an indicator electrode in potentiometric titration of La(III) ions with EDTA and for determining La(III) concentration in real samples.     

Zinc(II)-selective sensors based on dibenzo-24-crown-8 in PVC matrix

Membranes of dibenzo-24-crown-8 (I) as an ion active material in poly(vinylchloride) (PVC) based matrix have been tried for zinc(II)-selective sensors. The effect of anion excluder, sodium tetraphenylborate (NaTPB) and plasticizers, tris(2-ethylhexyl)phosphate (TEP), tributylphosphate (TBP), dibutylphthalate (DBP), dibutyl(butyl)phosphonate (DBBP), 1-chloronaphthalene (CN) and dioctylphthalate (DOP) on the performance of the membrane electrodes has also been studied. It was observed that the membrane having the composition (I): PVC:NaTPB:DOP in the ratio 10:200:2:100 gave the best results with a wide working concentration range of 9.2 × 10⁻⁵ to 1.0 × 10⁻¹ M, Nernstian slope of 29.0 ± 0. 5 mV/decade of activity, fast response time of 12 s and good selectivity over a number of mono-, bi-, and trivalent cations. The sensor works well in a pH range 4.8-6.2 and can be employed for the estimation of zinc ions in partially non-aqueous medium having up to 10% (v/v) methanol, ethanol or acetone content. The practical utility of the sensor has been demonstrated by using it successfully as an indicator electrode in the potentiometric titration of Zn²⁺ with EDTA and also for the determination of Zn²⁺ in a real sample analysis of wastewater.     

Selective removal of Cs and Re by precipitation in a Na<Subscript>2</Subscript>CO<Subscript>3</Subscript>–H<Subscript>2</Subscript>O<Subscript>2</Subscript> solution

The removal of Cs and Re (as a surrogate for Tc) by selective precipitation from the simulated fission products which were co-dissolved with uranium during the oxidative dissolution of spent fuel in a Na₂CO₃–H₂O₂ solution was investigated in this study. The precipitations of Cs and Re were examined by introducing sodium tetraphenylborate (NaTPB) and tetraphenylohosponium chloride (TPPCl), respectively. The precipitation of Cs by NaTPB and that of Re by TPPCl each took place within 5 min, and an increase in temperature up to 50 °C and a stirring speed up to 1000 rpm hardly affected their precipitation rates. The most important factor in the precipitation with NaTPB and TPPCl was found to be a pH of the solution after precipitation. Since Mo tends to co-precipitate with Cs or Re at a lower pH, an effective precipitation with NaTPB and TPPCl was done at pH of above 9 without the co-precipitation of Mo. More than 99% of Cs and Re were precipitated when the initial concentration ratio of NaTPB to Cs was above 1 and when that of TPPCl to Re was above 1. The precipitation of Cs and Re was never affected by the concentration of Na₂CO₃ and H₂O₂, even though they were raised up to 1.5 and 1.0 M, respectively. Precipitation yields of Cs and Re in a Na₂CO₃–H₂O₂ solution were found to be dependent on the concentration ratios of [NaTBP]/[Cs] and [TPPCl]/[Re].     

2,6-bis-methylsulfanyl-[1,3,5]thiadiazine-4-thione as a Ag+-selective ionophore.

A silver ion-selective electrode was prepared with a polymeric membrane incorporating 2,6-bis-methylsulfanyl-[1,3,5]thiadiazine-4-thione as an ionophore, tri-n-butylphosphate (TBP) as a plasticizer and sodium tetraphenylborate (NaTPB) as an additive. The electrode exhibited a near-Nernstian response of 52 mV/decade over a wide linear concentration range of 1.0 x 10(-5) - 1.0 x 10(-1) M with a lower detection limit of 9.77 x 10(-6) M. The electrode exhibited excellent selectivity for silver ion over many of the alkali, alkaline-earth and transition metal ions. The electrode worked well over a wide pH range of 1.77 - 7.13. The response time of the electrode was less than 20 s. The sensor can be applied as indicator electrode for the potentiometric titration of Ag+ ions with Cl- ions.     

Analysis of high-level waste for tetraphenylborate using HPLC

Summary One waste remediation process used at the Savannah River Site was the in-tank precipitation of the beta-emitting ¹³⁷Cs from high-level waste (HLW) using sodium tetraphenylborate (NaTPB) followed by processing the resulting decontaminated filtrate into grout at the Saltstone Production Facility (SPF). A simple method was developed for the monitoring of tetraphenylborate (TPB) in high-level waste (HLW) containing up to 0.38 Ci/gal of ¹³⁷Cs. Separation was achieved by extraction of the high sodium-bearing waste with acetonitrile followed by analysis using reversed-phase high performance liquid chromatography (HPLC). The sample preparation method allowed for the handling of an organic extraction layer that had 94% less acitivity than the HLW sample. The subsequent HPLC analysis of the extraction layer determined the TPB concentration in HLW waste to 0.8 mg/l with a %rsd of 8.     

Wire-coated silver(I) ion-selective electrode based on 2-mercaptobenzothiazole (MBT) ionophore: application to the determination of silver in real samples.

A new wire-coated silver ion-selective electrode with a wider concentration range (10(-7) M - 10(-1) M) was developed using 2-mercaptobenzothiazole (MBT) as a neutral ionophore. An optimum mixture of PVC, ionophore, dioctylphtalate (DOP) as a plasticizer and sodium tetraphenylborate (NaTPB) as an ion-pairing agent was used in preparing the coatings. The effect of various parameters, such as the electrode bed nature, coating composition and solution pH, on the efficiency of the electrode is described. It has been shown that platinum acts as a more suitable bed for electrode preparation, and exhibits a slope of 59.5 +/- 1 mV over the whole range of studied concentrations. The selectivity coefficient of the electrode towards various interfering cations as well as its reproducibility, response time and lifetime of the electrode were estimated. The developed electrode was successfully used for the determination of trace amounts of silver in human hair and photographic waste as real samples and in the potentiometric titration of halides as an indicator electrode.