共查询到20条相似文献,搜索用时 15 毫秒
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《Analytical letters》2012,45(2):43-51
Abstract A solid membrane potassium selective electrode has been developed. The following parameters of the potassium ion electrode were investigated; Nernstian response to potassium ion activity, response time to step changes in potassium ion activity, the effect of pH on potassium response, and the electrode response to other cations. 相似文献
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《Analytical letters》2012,45(5):343-346
Abstract An argentometric potentiometric method for the precise determination of formaldehyde using an iodide -ion electrode is described. Formaldehyde was determined by titrating the iodide-ion generated by the reaction with iodine in an alkaline medium. The accuracy and precision were better than 0.1% under the optimum condition. 相似文献
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《Analytical letters》2012,45(9):457-464
Abstract A new ammonium ion selective electrode has been developed and found to be capable of measuring ammonium ion in the presence of other cations. The electrode's selectivity over other cations is reported as well as its response time to step changes in ammonium ion activity. In addition, blood serum samples have been analyzed for urea content by treatment with urease with no special sample pre-treatment required. 相似文献
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《Analytical letters》2012,45(10):699-708
Abstract A method has been developed for the determination of sodium in alumina using a selective ion electrode. The alumina sample is dissolved in ammonium hydrogen fluoride in platinum crucibles or sintered with boric acid using either platinum, nickel, or zirconium crucibles. Either dissolution technique completely extracts all available sodium. After dissolution, and in the presence of citrate to prevent aluminum hydroxide precipitation, the pH is adjusted to 8.7 with ammonium hydroxide, and the sodium concentration is determined by a sodium selective ion electrode. 相似文献
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《Analytical letters》2012,45(10):523-535
Abstract A new solid-state cadmium ion selective electrode is evaluated. Interference effects are considered and the electrode is used to detect the endpoint in titrations of cadmium ion in water and in dimethylsulfoxide. 相似文献
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研究了氟离子选择电极瞬时电位分析法,其检出限和Nernst响应下限均低于传统电位分析法,空白液切换到试液时瞬时电位达到稳定的峰电位Vp比传统电位法的响应快得多,可以实现小体积试液的快速准确分析;用该法测定了自来水和矿泉水中氟的含量;利用校正曲线的截距和检出限计算了LaF3的溶度积,在0.1mol/L KNO3介质中Ksp(LaF3)=10^-28.45,在0.001mol/L柠檬酸钠+HAc-NaAc缓冲液(pH=5.50,离子强度I=0.10mol/L)介质中溶度积K′sp(LaF3)=10^-26.26;据此,计算得柠檬酸与La^3 络合物的稳定常数K1=10^5.46和K2=10^3.99;用离子水合吉氏自由能ΔGh(F^-,g)解释了不同浓度F^-试液瞬时电位的跃迁时间。 相似文献
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Emad Mohamed Hussien Maha Hegazy Laila Abdel Fattah Hisham Ezzat Abdellatef Mai Abd El-Aziz Heba Mohamed El-Sayed 《Electroanalysis》2022,34(3):494-500
Novel screen-printed electrodes (SPEs) were constructed for the quantitation of nicorandil (NIC) in its pharmaceutical formulations. Different ion-exchangers and plasticizers were investigated, but the optimal potentiometric response was obtained using nicorandil-phosphotungstate (NIC-PTA) ion associate and tricresyl phosphate as a plasticizer. A Nernstian response of 58.80±1 mV/decade was obtained over a concentration range of (1×10−6–1×10−2) M with 1×10−5 M as a detection limit. Sensor morphology was characterized using scanning electron microscopy (SEM). The method was validated for the assay of NIC with high selectivity, accuracy (average recovery=100.54 %), and precision (%RSD≤2). 相似文献
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离子选择性电极电位法测定钼矿石和钨矿石中氟 总被引:2,自引:0,他引:2
采用过氧化钠熔融钼矿石、钨矿石样品,乙二胺四乙酸钠和5-磺基水杨酸混合溶液浸取盐分,将样品溶液静置12h,吸取上层清液,以乙二胺四乙酸钠-硝酸钾组成的混合溶液作为总离子强度缓冲剂,控制溶液pH值为5.1,使用pF-1型氟离子选择电极,以饱和甘汞电极作参比电极测定溶液的平衡电位值。采用标准曲线法测定钼矿石和钨矿石中氟。钼矿石标准物质测定值的相对标准偏差(n=11)为3.36%,经4种国家一级钼矿石、钨矿石标准物质的分析验证,测定结果与标准值吻合。 相似文献
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铜的催化动力学电位法测定 总被引:4,自引:0,他引:4
本文报道了利用碘离子选择电极监测H2O2-KI氧化还原反应体系被Cu(Ⅱ)催化的反应速度,建立了测定Cu(Ⅱ)的催化动力学方法,其线性范围为10-80ng/mL,该法用于铝合金标样中铜的测定,结果非常接近标准样品的标准值,相对标准偏差为0.36%,回收率在98.3%-105.6%之间。 相似文献
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建立了氟离子选择性电极对食品添加剂硫酸钙中氟离子含量的测定方法,通过标准曲线法进行定量,线性相关系数为0.999 1,线性范围为0.2~3.0μg/mL,方法的相对标准偏差为3.2%,加标回收率为97.8%~102.0%,实验结果表明所建立的方法简单、快速、准确,适用于食品级硫酸钙中氟离子含量的测定。 相似文献
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《Analytical letters》2012,45(13):2263-2274
Abstract This paper reports the potentiometric measurement of ascorbic acid in the solution of 0.10 mol/L NaOH-0.1 mol/L NaCl using carbon paste (the mixture of spectroscopic graphite powder and di-iso-octyl phthalate) electrode(room temperature 15°C), with the linear range 7.0 × 10?7 × 4.0 × 10?5mol/L, average response slope 95mV/decade and detection limit 1 × 10?7mol/L. Phenol, sulfite, Mn2+ and so on pose no interference to the measurement of ascorbic acid. This method is characterized by fine selectivity, reproducibility and accuracy. The potential response behavior is caused chiefly by chemisorption of ascorbic acid to the surface of the carbon. Each year yields a number of papers concerning the determination of ascorbic acid by various methods, including gas chromatographymass spectrometry1, capillary electrophoresis2, spectrophotometry3, voltammetry4, titrimetric method5, biosensor6 and so on, Each method has its merits and defects in analyzing different samples. M. Petersson7 worked out the potentiometric sensor for determining ascorbic acid by modifying monolayer of ferrocene upon the surface of half-oxidized platinum electrode with an average response slope 50±8.8mV/decade, but this sensor suffers from inadequate selectivity. In our study, carbon paste electrode (without ionophore) is applied in the determination of ascorbic acid by potentiometry with an average response slope 95mV/decade. This method displays fine selectivity, accuracy, convenience and rapidity of determination. 相似文献
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G. Y. Aguilar Lira G. A. Álvarez Romero T. de J. Licona Sánchez M. E. Páez Hernández C. A. Galán Vidal M. A. Romero Romo 《Electroanalysis》2013,25(6):1519-1527
This work presents the results obtained on the construction of a potentiometric ion‐selective electrode based on a polypyrrole (PPy) selective membrane to quantify the benzoate ion in nonalcoholic beverages. The electrode modification with benzoate (Benz?1) ion doped‐Ppy was carried out under an imposed potential, while the electrosynthesis optimization was undertaken using the modified Simplex method, such that the film’s sensitivity was maximized toward the benzoate ion. The maximum sensitivity recorded was ?52.02±1.55 mV/decade [Benz?1] using a graphite powder‐araldite resin composite electrode. During the modified electrode’s characterization it was found out that the response and drift were relatively short, namely 2 min and 0.4 mV min?1 respectively, within the 7 to 9 pH range, exhibiting a detection limit of 7×10?4 mol L?1 and a quantification range of 3×10?3 at 10?1 mol L?1. Selectivity coefficients were evaluated with the Matched Potential Method obtaining in all cases values much less than 1. The benzoate concentration in commercially available juices and sweetened beverages was evaluated comparing the results obtained with the proposed ion‐selective electrode and those of HPLC, the usually accepted technique. A statistical analysis of the results led to the conclusion that there exists no meaningful difference between the results obtained with both techniques, which shows the usefulness of the ion‐selective electrode to proceed with the quantification in real samples. 相似文献
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《Analytical letters》2012,45(5):423-428
Abstract A liquid membrane soap or surfactant sensitive electrode capable of working throughout the pH range 1–13 has been developed. The active substance of the electrode is the ion-association complex of dodecylbenzene sulphonate with bisdimethylglyoxime-o-phenanthroline-cobaltate(III). The electrode enables soap or surfactant titration depending on the pH. 相似文献
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《Analytical letters》2012,45(17):2928-2936
Abstract A simple, rapid, and reliable potentiometric method is described for determination of ranitidine hydrochloride in pharmaceutical formulations. Experiments were performed to determine the suitability of using a chloride-ion selective electrode for the indirect estimation of ranitidine hydrochloride. The precision and accuracy of the potentiometric method were determined. We found that they not differ significantly. The advantage of the proposed method is the fact that it can be applied without filtration of the drug sample before analysis. 相似文献
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Anjali Upadhyay Ashok Kumar Singh Koteswara Rao Bandi A. K. Jain 《Electroanalysis》2013,25(11):2453-2462
Novel Zn2+ ion‐selective PVC based coated graphite electrodes were fabricated using the ionophores N‐((1H‐indol‐3‐yl)methylene)thiazol‐2‐amine (I1), N‐((1H‐indol‐3‐yl)methyl)‐thiazol‐2‐amine (I2) and 1‐((1H‐indol‐3‐yl)methylene)urea (I3). Their potentiometric performance was examined in dependence of the addition of plasticizers and anion excluders and compared. It is found that the coated graphite electrode with the composition I1:KTpClPB:o‐NPOE:PVC=9 : 1.5 : 51 : 38.5 is the best with respect to the wide working concentration range (4.2×10?8–1.0×10?1 mol L?1), low detection limit (1.6×10?8 mol L?1) and wide pH range of 3.0–8.0. The proposed electrode was successfully applied to quantify Zn2+ in various environmental, biological and medicinal plant samples and used as indicator electrode. 相似文献