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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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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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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
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用石墨粉填充苯乙烯-丙烯腈共聚树脂(AS树脂),挤出成型,制取AS树脂/石墨复合导电材料电极.用红外光谱、循环伏安等手段表征了电极的结构及特性.电极对测定Ag+有较好的选择性、稳定性和再现性,并较一般玻碳电极更易化学修饰 相似文献
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Mohamed A. F. Elmosallamy Mohamed M. Ghoneim Hamada M. A. Killa Amr L. Saber 《Mikrochimica acta》2005,151(1-2):109-113
A potentiometric poly(vinyl chloride) membrane sensor for determination of saccharin is described. It is based on the use of Aliquat 336S-saccharinateion-pair as an electroactive material in plasticized PVC membranes with o-nitrophenyloctylether or dioctylphthalate. The sensor is conditioned for at least two days in 0.1 mol L−1 sodium saccharinate before use. It exhibits fast, stable and Nernstian response for saccharinate ions over the concentration range of 1.0 × 10−1–5.0 × 10−5 mol L−1 and pH range of 4.5–11. The sensor is used for determination of saccharin in some dosage forms. Results with an average recovery of 101% and a mean standard deviation of 0.2% are obtained which is compared favourably with data obtained using the British pharmacopoeia method. The sensor shows reasonable selectivity towards saccharin in presence of many anions and natural sweeteners. 相似文献
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本文概述了聚合物膜离子选择电极的发展、制备、应用等方面的研究情况。分别对固态膜类和液膜类聚合物膜离子选择电极的优缺点和发展前景进行了分析,并讨论了聚合物在膜电极中的作用,以及聚合物的结构对膜电极性能的影响。 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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Electroanalytical Studies of Chromone Based Ionophores for the Selective Determination of Arsenite Ion 下载免费PDF全文
Neha Gupta Ashok Kumar Singh Shubhrajyotsna Bhardwaj Divya Singhal 《Electroanalysis》2015,27(5):1166-1175
Two chemosensors 4H‐1‐benzopyran‐3‐carboxaldehyde, 4‐oxo‐, 3‐(2‐phenylhydrazone), [I1] and 4H‐1‐benzopyran‐3‐carboxaldehyde, 4‐oxo‐, 3‐[2‐(2,4‐dinitrophenyl)hydrazone], [I2] with hydrazone‐NH group as binding site have been shown excellent selectivity for arsenite ion. It is confirmed by the UV‐vis titration that I2 is more selective than I1. The performance of the coated graphite electrode (CGE) was found to be better than polymeric membrane electrode (PME) in terms of linear range of 4.89×10?7–1.0×10?1 mol L?1, low detection limit of 8.31×10?8 mol L?1 and short response time. The proposed sensors were also used to determine the arsenite ion in different water samples. 相似文献
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A novel nano-TiO2 polymer modified glassy carbon (GC) electrode was developed for the determination of an organophosphorous pesticide, fenitrothion (-NO2), in citrate buffer solution. The electrochemical behavior of fenitrothion was characterized by using cyclic voltammetry. An irreversible form, -NO2, was transformed into a reversible redox couple (-NHOH/-NO), and it can be used to determine trace fenitrothion by square wave voltammetry. The experimental parameters, such as film thickness, pH value, accumulation potential and time were optimized. Interestingly, a cyclic voltammetric scan was observed to be more effective than a constant potential for the accumulation of fenitrothion. A linear response over a fenitrothion concentration of 2.5×10–8 to 1.0×10–5M was exhibited, with a detection limit of 1.0×10–8M (S/N=3). The high sensitivity and selectivity of this film electrode was demonstrated by its practical application to the determination of trace amounts of fenitrothion in lake water and apple samples. 相似文献
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《Analytical letters》2012,45(7):425-435
Abstract An analysis of the potentiometric titration curves for the silver-cyanide system indicates two possible approaches to the determination of cyanide ion at low levels. Both involve an indirect measurement of the silver ion in equilibrium with argentocyanide complex. These procedures are considerably more sensitive than the conventional method using a “silver iodide” cyanide responsive electrode. 相似文献
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用电化学还原方法制备了一种锇联吡啶氧化还原聚合物(POs-EA)膜修饰电极,并研究了其在磷酸缓冲溶液中的电化学行为和对肾上腺素的电催化氧化作用. 结果表明,该修饰电极表现出较为可逆的伏安响应并对肾上腺素的电化学氧化具有良好的电催化性能. 与裸金电极相比, POs-EA膜修饰电极大大提高了肾上腺素的峰电流,降低了肾上腺素的氧化峰电位. 初步探讨了该电极上肾上腺素的电催化氧化机理. 通过检测外加电位为0.29 V时的氧化电流对肾上腺素进行检测,结果表明,其氧化电流和肾上腺素的浓度在5×10-8~1×10-5 mol/L范围内呈良好线性关系,检测限可达1.5×10-8 mol/L. 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(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(11):793-798
Abstract A series of anion selective electrodes of the liquid membrane type have been examined with respect to selectivity characteristics. The resulting selectivity data are examined in terms of theory of liquid membrane electrodes and correlations are made with extraction constants. 相似文献
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制备了一种以盐酸地尔硫卓与碘汞酸盐形成的缔合物为电活性物质的聚氯乙烯膜盐酸地尔硫卓选择电极,并对其性能做了测定,结果显示该电极对盐酸地尔硫卓有较好的能斯特响应。盐酸地尔硫卓的线性范围为4.5×10~(-2)~1.0×10~(-4)mol·L~(-1),检出限为3.55×10~(-5)mol·L~(-1)。该电极用于盐酸地尔硫卓片剂的分析,结果与药典法结果相符。 相似文献
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Anjali Upadhyay A. K. Singh A. K. Jain Vinod Kumar Gupta Koteswara Rao Bandi 《Electroanalysis》2012,24(7):1630-1638
Preliminary studies on the two Schiff bases N2‐((3H‐indol‐3‐yl)methylene)‐6‐phenyl‐1,3,5‐triazine‐2,4‐diamine (L1) and N2,N4‐bis((3H‐indol‐3‐yl)methylene)‐6‐phenyl‐1,3,5‐triazine‐2,4‐diamine (L2) have shown that they can act as Sm3+ selective electrodes. The performances of a polymeric membrane electrode and a coated graphite electrode based on L2 were compared and the CGE proved to be better, as it shows a low detection limit of 1.8×10?8 mol L?1, a Nernstian slope of 19.6±0.4 mV decade?1 of activity with a response time of 11 s in the pH range of 3.0–9.0. The CGE was used to determine Sm3+ in medicinal plants and soil samples. It was also used to determine fluoride ions in mouthwash samples and in toothpaste. 相似文献