• Title/Summary/Keyword: potentiometric sensor

검색결과 66건 처리시간 0.025초

Effect of Surfactants on the Electrochemical Performance of Cation-Selective Membrane Electrodes

  • Oh, Hyun-Joon;Cha, Geun-Sig;Nam, Hak-hyun
    • Bulletin of the Korean Chemical Society
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    • 제24권1호
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    • pp.37-44
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    • 2003
  • We examined the effect of polyether-type nonionic surfactants (Brij 35, Triton X-100, Tween 20 and Tween 80) on the potentiometric properties of sodium-, potassium- and calcium-selective membranes which are prepared with widely used ionophores and four kinds of polymer matrices [poly(vinyl chloride) (PVC), polyurethane (PU), PVC/PU blend, and silicone rubber (SR)]. It was found that the PVC-based membranes, which provide the best performance among all other matrix-based membranes in the absence of nonionic surfactants, exhibited larger change in their potentiometric properties when nonionic surfactants are added to the sample solution. On the other hand, the sodium-selective SR-based membrane with calix[4]arene, potassium-selective PVC/PU- or SR-based membrane with valinomycin, and the calcium-selective SR-based membrane with ETH 1001 provide almost identical analytical performance in the presence and absence of Tween 20 or Tween 80 surfactants. The origin of nonionic surfactants effect was also investigated by interpreting the experimental results obtained with various matrices and ionophores. The results suggest that the nonionic surfactant extracted into the membrane phase unselectively form complexes with the primary and interfering ions, resulting in increased background potential and lower binding ability for the ionophore. Such effects should result in deteriorated detection limits, reduced response slopes and lower selectivity for the primary ions.

A Novel Iron(III) Selective Membrane Electrode Containing a Tripodal Polycatacholamine as Sensor

  • Bera, Rati Kanta;Sahoo, Suban K;Baral, Minati;Kanungo, B.K.
    • Bulletin of the Korean Chemical Society
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    • 제32권10호
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    • pp.3592-3596
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    • 2011
  • A novel poly(vinylchloride)-based membrane sensor using $N^1$,$N^3$,$N^5$-tris(2-(2,3-dihydroxybenzylamino)-ethyl)cyclohexane-1,3,5-tricarboxamide (CYCOENCAT, L) as ionophore has been prepared and explored as $Fe^{3+}$ selective electrode. The membrane electrode composed of ionophore, poly(vinylchloride) and o-nitropheyloctyl ether in the optimum ratio 4:33:63 gave excellent potentiometric response characteristics, and displayed a linear log[$Fe^{3+}$] versus EMF response over a wide concentration range of $1.0{\times}10^{-5}-1.0{\times}10^{-1}$ M with super nernstian slope of 28.0 mV/decade and the detection limit of $8.0{\times}10^{-6}$ M. The proposed ion selective electrode showed fast response time (< 15 s), wide pH range (3.0-7.0), high non-aqueous tolerance (up to 20%) and adequate long life time (120 days). It also exhibited very good selectivity for $Fe^{3+}$ relative to a wide variety of alkali, alkaline earth, transition and heavy metal ions. Further, the analytical applicability of the sensor was tested as an indicator electrode in the potentiometric titration of $Fe^{3+}$ with EDTA.

Fabrication of Potentiometric Sodium-ion Sensor Based on Carbon and Silver Inks and its Electrochemical Characteristics (탄소 및 은 잉크 기반의 전위차 나트륨 이온 센서 제조 및 이의 전기화학적 특성)

  • Kim, Seo Jin;Son, Seon Gyu;Yoon, Jo Hee;Choi, Bong Gill
    • Applied Chemistry for Engineering
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    • 제32권4호
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    • pp.456-460
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    • 2021
  • A potentiometric sodium-ion (Na+) sensor was prepared using a screen-printing process with carbon and silver inks. The two-electrode configuration of the sensor resulted in potential differences in Na+ solutions according to Nernstian equation. The obtained Na+-sensor exhibited an ideal Nernstian sensitivity, fast response time, and low limit of detection. The Nernstian response was stable when the sensor was tested for repeatability and long-term durability. The Na+-selective membrane coated onto the carbon electrode selectively passed sodium ions against interfering ions, indicating an excellent selectivity. The portable Na+-sensor was finally fabricated using a printed circuit system, demonstrating the successful measurements of Na+ concentrations in various real samples.

Sub-Micro Molar Monitoring of La3+ by a Novel Lanthanum PVC-Based Membrane Sensor Based on 3-Hydroxy-N'-(pyridin-2-ylmethylene)-2-naphthohydrazide

  • Ganjali, Mohammad Reza;Norouzi, Parviz;Yousefian, Nasrin;Faridbod, Farnoush;Adib, Mehdi
    • Bulletin of the Korean Chemical Society
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    • 제27권10호
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    • pp.1581-1586
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    • 2006
  • A La (III) ion-selective membrane sensor has been fabricated from poly vinyl chloride (PVC) matrix membrane, containing 3-hydroxy-N'-(pyridin-2-ylmethylene)-2-naphthohydrazide (HPMN) as a neutral carrier, potassium tetrakis (p-chlorophenyl) borate (KTpClPB) as an anionic excluder and ortho-nitrophenyloctyl ether (NPOE) as a plasticizing solvent mediator. The effects of membrane composition and pH as well as the influence of the anionic additive on the response properties were investigated. The sensor with 30% PVC, 62% solvent mediator, 6% ionophore and 2% anionic additive, shows the best potentiometric response characteristics. It displays a Nernstian behavior (19.2 mV per decade) across the range of $1.0{\times}10^{-2}-1.0{\times}10^{-7}$ M. The detection limit of the electrode is $7.0{\times}10^{-8}$ M ($\sim$10 ng/mL) and the response time is 15 s from $1.0{\times}10^{-2}$ up to $1.0{\times}10^{-4} $M and 30 s in the range of $1.0 {\times}10^{-5}-1.0{\times}10^{-7}$ M. The sensor can be used in the pH values of 3.0-9.0 for about seven weeks. The membrane sensor was used as an indicator electrode in the potentiometric titration of lanthanum ions with EDTA. It was successfully applied to the lanthanum determination in some mouth wash preparations.

Development of Voltammetric Urea Sensors Based Poly(3-methylthiophene) film (Poly(3-methylthiophene)막 위에 urease를 고착시킨 Voltammetric Urea Sensor의 개발)

  • 박성호;진준형;홍석인;민남기
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
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    • pp.314-316
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    • 2000
  • Urea is detected as an indicator of renal disease in the human body. For these reasons, many biosensors for urea have been developed based on the enzymatic reaction of urea hydrolysis catalyzed by urease. Potentiometric method is applied reversible reaction system. But urea hydrolysis reaction may not has a reversible reaction mechanism in electrode surface. Therefore we applied to voltammtricmethod to obtain a sensitivity curve. The sensitivity of sensors was 34 ${\mu}$A/decade.

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Simple Iysine sensing system using $CO_{2}$ electrode and enzyme immobilized to CNBr-activated sepharose 4B

  • Kim, Eun-Jung;Koh, Kwang-Nak;Choi, Myung-Sook
    • Journal of Sensor Science and Technology
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    • 제6권6호
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    • pp.437-444
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    • 1997
  • A potentiometric L-lysine-selective sensor is described for the direct determination of lysine. The sensor system is based on a carbon dioxide gas sensing electrode and an L-lysine decarboxylase immobilized to CNBr-activated sepharose 4B. A highly selective L-lysine sensor has been prepared with immobilizing enzyme slurry put into reaction buffer solution. The optimum conditions for the measurement were evaluated by various experiments. This sensor exhibits a linear response to L-lysine concentrations from $10^{-4}M$ to $10^{-1}M$. Response time of this lysine sensor is shorter than 30secs and the immobilized enzyme slurry is stable over one year.

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Novel Triiodide PVC-Based Membrane Sensor Based on a Charge Transfer Complex of Iodine and Bis(2-hydroxyacetophenone)butane-2,3-dihydrazone

  • Ganjali, Mohammad Reza;Norouzi, Parviz;Shirvani Arani, Simindokht;Salavati Niasari, Masoud
    • Bulletin of the Korean Chemical Society
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    • 제26권11호
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    • pp.1738-1742
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    • 2005
  • In this study a novel triiodide ion-selective electrode based on a charge transfer complex of iodine and Bis(2-hydroxyacetophenone)butane-2,3-dihydrazone (ICT), as a membrane carrier was prepared. The electrode has a linear dynamic range between 1.0 ${\times}$ $10^{-2}$ and 5.0 ${\times}$ $10^{-7}$ M, with a Nernstian slope of 58. 99 ${\pm}$ 0.3 mV $decade^{-1}$ and detection limit of 3.0 ${\times}$ $10 ^{-7}$ M. The potentiometric response of the proposed sensor is independent of the pH of the solution in the pH range of 3.0-10.0. The electrode possesses the advantages of short conditioning time, fast response time, and especially, very good selectivity over a large number of common organic and inorganic anions. The electrode can be used for at least 6 months without any considerable divergences in the potentials. It was used as an indicator electrode in potentiometric titration of triiodide ion with thiosulfate.

Novel Silver(I) Ion Selective PVC Membrane Electrode Based on the Schiff Base (N2E,N2'E)-N2,N2'-Bis(Thiophen-2-ylmethylene)-1,1'-Binaphthyl-2,2'-Diamine

  • Jeong, Eunseon;Ahmed, Mohammad Shamsuddin;Jeong, Hae-Sang;Lee, Eun-Hee;Jeon, Seung-Won
    • Bulletin of the Korean Chemical Society
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    • 제32권3호
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    • pp.800-804
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    • 2011
  • A potentiometric sensor based on the Schiff base $(N^2E,N^{2'}E)-N^2,N^{2'}$-bis(thiophen-2-ylmethylene)-1,1'-binaphthl-2,2'-diamine has been synthesized and explored as an ionophore PVC-based membrane sensor selective for the silver ($Ag^+$) ion. Potentiometric investigations indicate a high affinity of this receptor for the silver ion. Seven membranes have been fabricated with different compositions, with the best performance shown by the membrane with an ionophore composition (w/w) of: 1.0 mg, PVC: 33.0 mg, DOA: 66.0 mg in 1.0 mL THF. The sensor worked well within a wide concentration range of $1.0{\times}10^{-2}$ to $1.0{\times}10^{-7}$ M, at pH 5, at room temperature (slope 57.4 mV/dec.), and with a rapid response time of 9 s; the sensor also showed good selectivity towards the silver ion over a huge number of interfering cations, with the highest selectivity coefficient for $Hg^{2+}$ at -3.7. Thus far, the best lower detection limit was $4.0{\times}10^{-8}$ M.