• Bulletin of the Korean Chemical Society
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• 제33권4호
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• pp.1247-1252
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• 2012

In this paper, a potentiometric sensor based on polyaniline conducting polymer for potentiometric determination of Cr (VI) ions is reported. Polyaniline was synthesized electrochemically (cyclic voltammetry method) onto a micro pencil graphite electrode (0.7 mm diameter) in the presence of HCl and diphenylcarbazide (termed as (PGE/PAni/DPC). Some initial experiments were performed in order to find out the optimized conditions for preparation of the introduced Cr (VI) sensor electrode. The plot of E vs. log [Cr (VI)], showed a linear response in the range from $1.0{\times}10^{-6}$ to $1.0{\times}10^{-1}$ M. High repeatability with the detection limit of $8.0{\times}10^{-7}$ M was obtained.

• Bulletin of the Korean Chemical Society
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• 제29권9호
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• pp.1774-1780
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• 2008

New PVC based polymeric membrane electrodes (PME) and coated glassy carbon electrodes (CGCE) based on synthesized Schiff base complexes of Co(III); [Co(Salen)$(PBu_3)_2$]$ClO_4$, [Co($Me_2$Salen)$(PBu_3)_2$]$ClO_4$, [Co(Salen)$(PBu_3)H_2O$]$ClO_4$; as anion carriers for potentiometric determination of $ClO_4\;^-$were studied. The PME and also CGCE electrodes prepared with [Co(Me2Salen)$(PBu_3)_2$]$ClO_4$ showed excellent response characteristics to perchlorate ions. The electrodes exhibited Nernstian responses to $ClO_4\;^-$ ions over a wide concentration range with low detection limits ($1.0 {\times} 10^{-6}\;mol\;L^{-1}$ for PME and $9.0 {\times} 10^{-7}\;mol\;L^{-1}$ for CGCE). The electrodes possess fast response time, satisfactory reproducibility, appropriate lifetime and, most importantly, good selectivity toward $ClO_4\;^-$ relative to a variety of other common inorganic anions. The potentiometric response of the electrodes is independent of the pH in the pH range 2.5-8.5. The proposed sensors were used in potentiometric determination of perchlorate ions in mineral water and urine samples. The interaction of the ionophore with perchlorate ions was shown by UV/Vis spectroscopy.

• 약학회지
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• 제45권1호
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• pp.29-33
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• 2001

A method for the determination of anionic drug, mefenamate with ion-selective electrode using Fe(II)-1,10-phenanthroline chelate as a counter ion was developed. Benzyl nitrophenyl ether (BNPE) plasticized membrane was more selective and sensitive than the other tested membranes. This membrane electrode exhibits a linear response for 10$^{-2}$ M~5 $\times$ 10$^{-5}$ M of mefenamic acid with a slope of -61.4 mV/dec. in borate buffer solutions (pH 9.0). Potentiometric selectivity measurements revealed negligible interferences from various organic and ionorganic anions. Direct potentiometry and potentiometric titration method of mefenamic acid in capsule preparations are presented and compared.

• 대한화학회지
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• 제20권4호
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• pp.277-279
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• 1976

은 전극을 지시전극으로 하고 표준칼로멜 전극을 기준전극으로 하여 전압플로위회로를 이용하여 수용액에서 2,5-dimercapto-1,3,4-thiadiazole에 의한 구리의 전위차 적정법을 연구하였다. 이 시약은 구리의 전위차 적정 정량에 뛰어나게 이용할 수 있었고 여러가지 가리움제를 사용하여 다른 이온들의 존재하에 대기중에서 미량의 구리를 직접 적정할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2722-2726
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• 2011

Plasticized poly(vinyl chloride), PVCs, with different membrane compositions tested for use in the construction of an ion-selective sensor for the determination dibucaine. A prepared membrane with dioctyl phthalate-PVC and ion-pair of N-(1-naphthyl)ethylenediamine dihydrochloride-tetraphenyl borate had a good potential to acts as a potentiometric sensor for the analysis of dibucaine. A linear relationship was obtained between potential and logC varying between $1.0{\times}10^{-6}$ and $1.0{\times}10^{-2}$ M dibucaine with a good repeatability and reproducibility. The sensor was applied for the determination of the drug in pharmaceuticals and biological fluids such as plasma and urine samples with satisfactory results. The drug electrode has also been used to study the interaction of bovine serum albumin (BSA) with dibucaine. The saturated quantities of dibucaine binding were 13.04, 5.30 and 9.70 mol/mol in 0.01, 0.02 and 0.1% of protein, respectively.

• Carbon letters
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• 제27권
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• pp.50-63
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• 2018

An imprinted potentiometric sensor was developed for direct and selective determination of gabapentin. Sensor is based on carbon paste electrode adapted by graphene oxide that is decorated with silver nanoparticles and mixed with molecularly imprinted polymers nanoparticles using gabapentin as a template molecule. The synthesized nanoparticles were characterized by Fourier transmission infrared spectroscopy, transmission electron microscopy and X-ray diffraction. Under optimal experimental conditions, the studied sensor exhibited high selectivity and sensitivity with LOD of $4.8{\times}10^{-11}mol\;L^{-1}$. It provided a wide linearity range from $1{\times}10^{-10}$ to $1{\times}10^{-3}mol\;L^{-1}$ and high stability for more than 3 mo. The sensor was effectively used for the determination of gabapentin in pharmaceutical tablets and spiked plasma samples.

• 한국식품과학회지
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• 제36권6호
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• pp.885-892
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• 2004

본 실험에서는 성장기용 조제식에 함유된 유지를 대상으로 전위차 적정법 및 뷰렛 적정법에 의한 과산화물가를 측정하고 그 측정불확도를 비교하여 산정하였다. GUM(Guide to the expression of uncertainty in measurement) 및 Draft EURACHEM/CITAC Guide의 이론에 기초하여 측정불확도를 구하였으며, 불확도 인자로서 적정액의 농도, 시료량 및 적정량 등이 작용하였다. 뷰렛적정에 의한 과산화물가 측정값과 확장불확도는 $2.05{\pm}0.17\;meq/kg$ 으로 표현되었으며, 전위차적정에 의한 경우는 $1.96{\pm}0.07\;meq/kg$ 으로 표현되었다. 적정과정에서의 측정불확도가 전체불확도의 대부분을 차지하였으며, 전위차적정법에 의한 측정불확도는 뷰렛적정법에 의한 경우보다 낮게 나타나 과산화물가가 낮은 시료의 측정시에 바람직한 측정방법으로 사료되었다.

• Journal of Electrochemical Science and Technology
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• 제14권1호
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• pp.66-74
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• 2023

In this study, a new potentiometric sensor selective to copper(II) ions was developed and characterized. The developed sensor has a polymeric membrane and contains 4.0% electroactive material (ionophore), 33.0% poly(vinyl chloride) (PVC), 63.0% bis(2-ethylhexyl)sebacate (BEHS) and 1.0% potassium tetrakis(p-chlorophenyl)borate (KTpClPB). This novel copper(II)-selective sensor exhibits a Nernstian response over a wide concentration range from 1.0×10^-6 to 1.0×10^-1 mol L^-1 with a slope of 29.6 (±1.2) mV decade^-1, and a lower detection limit of 8.75×10-7 mol L^-1. The sensor, which was produced economically by synthesizing the ionophore in the laboratory, has a good selectivity and repeatability, fast response time and stable potentiometric behaviour. The potential response of the sensor remains unaffected of pH in the range of 5.0-10.0. Based on the analytical applications of the sensor, we showed that it can be used as an indicator electrode in the quantification of Cu²⁺ ions by potentiometric titration against EDTA, and can also be successfully utilized for the determination of copper(II) ions in different real samples.

• 분석과학
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• 제8권4호
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• pp.691-698
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• 1995

The complexation of platinum and palladium with synthetic polyelectrolytes was studied. The successive and overall stability constants of Pd(II) with PEI and 2PVP were obtained by potentiometric titration. Because of the slow equilibrium time, the potentiometric titrations were performed using the home-made automatic titrator in order to analyze the complexations according to the modified Bjerrum method. The complex formation constant of Pt(IV) with 2PVP, measured by differential pulse polarography, was calculated from the peak currents that were obtained in non-complexing media and in solution containing 2PVP.

• Preventive Nutrition and Food Science
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• 제4권1호
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• pp.79-83
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• 1999

A potentiometric biosensor employing a CO3-2 ion-selective electrode(ISE) and malic enzyme immobilization in al flow injection analysis (FIA) system was constructed. Analytical parameters were optimized for L-malate determination . The CO3-2 -ISE-FIA system was composed of a pump, an injector, a malic enzyme (EC1.1.1.40) reactor, a CO3-2 ion-selective electrode, a pH/mV meter and a recorder. Cofactor NADP was also injected with substrate for theenzyme reaction into the system. Optimized analytical parameters for L-malate determination in the CO3-2 ISE-FIA system were as follows ; flow rate, 14.5ml/hr ; sample injection volume, 100ul; enzyme loading in the reactor, 20 units ; length of the enzyme reactor , 7 cm ; tubing length form the enzyme reactor to the detector as a geometric factor in FIA, 15 cm . The response time for measuring the entire L-malate concentration range (10-2 ~10-5 mol/L ; 4 injections )was <15minutes . In this CO3-2 -ISE-FIA system, the potential differences due to th eformation of CO3-2 by the reaction of malic enzyme on L-malate were correlated to L-malate concentration in the range of 10-2 ~10-5mol/L ; the detection limit was 10-5 mol/L. This potentionmetric CO3-2 ISE--FIA system was found to be useful for L-malate measurement.