• Title/Summary/Keyword: Nernstian response

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A hydrogen ion-selective membrane electrode based on N,N,N,N-Tetrabenzylethylenediamine as neutral carrier (N,N,N,N-Tetrabenzylethylenediamine 중성운반체를 이용한 수소 이온 선택성 막전극)

  • Jeong, Seong-Suk;Park, Myon-Yong;Chung, Koo-Chun;Cho, Dong-Hoe;Lee, Kyeong-Jae;Kim, Jae-Woo
    • Analytical Science and Technology
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    • v.8 no.2
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    • pp.187-193
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    • 1995
  • A PVC membrane ion-selective electrodes based on N,N,N,N-tetrabenzylethylenediamine as neutral carrier has been prepared by addition of plasticizers such as phthalates and sebacate and liphophillic additives such as NaTPB. The membrane electrodes were investigated to the electric resistance, response range to hydrogen ion and the interfering effect of alkali and alkline earth metals. A electric resistance hardly had on effect of plasticizers. In case of 0.7% NaTPB added to membrane, response of the electrodes were shown the values near to theoretical Nernstian slope and interferences by alkali and alkaline earth metal were few influenced. The performances of pH-selective electrodes were shown linerality to hydrogen ion between pH 2 and 10 in the presense of alkali and alkaline earth ions. Reproducibility and stability tests were shown good results in the same pH range.

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Study on PVC Mixed Silver Iodide Membrane Electrode (PVC 를 섞은 요오드화은 막전극에 관한 연구)

  • Kwon Young-Soon;Kim Jung-Hee;Park Kee-Chae
    • Journal of the Korean Chemical Society
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    • v.20 no.6
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    • pp.486-493
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    • 1976
  • The PVC mixed silver iodide pellet was prepared by means of the Infrared Pellet presser and the pellet was used as an indicating membrane electrode, to measure the potentials for various silver ion activities, ranging from $10^{-1}$ to $10^{-6}$ M. The potential responses to silver ion activities were linear and the slope was much close to Nernstian relation as compared with that of the pure silver iodide pellet membrane electrode and the PVC coated silver iodide pellet membrane electrode. The mechanical property and chemical durability of this electrode were found much better than the others. This electrode did not show significant response to the other except silver ion, but had good response to halide ions, i.e., iodide, chloride, bromide and cyanide ions, in the concentration range $10^{-1}$ to $10^{-6}$ M. This electrode could be used as an indicating electrode in potentiometric titrations of single halide ion and also halide mixture with standard solution of silver nitrate.

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A New PVC-Membrane Electrode Based on a Thia-Substituted Macrocyclic Diamide for Selective Potentiometric Determination of Silver Ion

  • Shamsipur, Mojtaba;Kazemi, Sayed Yahya;Niknam, Khodabaksh;Sharghi, Hashem
    • Bulletin of the Korean Chemical Society
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    • v.23 no.1
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    • pp.53-58
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    • 2002
  • A new PVC-membrane electrode for $Ag^+$ ion based on a thia-substituted macrocyclic diamide has been prepared. The electrode exhibited a Nernstian response for $Ag^+$ over a wide concentration range $(1.7{\times}10^{-6}-1.0{\times}10^{-1}M)$. It has a response time <15 s and can be used for at least 3 months without divergence. The proposed membrane sensor revealed good selectivities for $Ag^+$ over a variety of metal ions and can be used in a pH range 3.0-7.5. It has been used successfully for direct determination of $Ag^+$ in different real samples and, as an indicator electrode, in the titration of silver ion.

Highly Copper(II)-selective PVC Membrane Based on a Schiff Base Complex of N,N'-Bis-pyridin-2-ylmethylene-naphthalene-1,8-diamine as an Ionophore

  • Jeong, Dae-Cheol;Lee, Hyo-Kyoung;Jeon, Seung-Won
    • Bulletin of the Korean Chemical Society
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    • v.27 no.10
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    • pp.1593-1596
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    • 2006
  • The polymeric membrane electrodes based on N,N'-bis-pyridin-2-ylmethylene-naphthalene-1,8-diamine as an ion carrier were prepared and tested for the copper-ion selective electrode. The membrane has a linear dynamic range between $10^{-6}$ and $10^{-2}$ M with a Nernstian slope of 29.6 mV per decade, and its detection limit was $10^{-5.62}$M. The potentiometric response is independent of the pH range of 3-5. The proposed electrode showed good selectivity and response for $Cu^{2+}$ over a wide variety of other metal ions in pH 4.0 buffer solutions.

Nitrate Ion-Selective Membrane Electrode Based on Complex of Ammonia Modified Bakelite A-Ni(II) Nitrate (Bakelite A-Ni(II) 착물의 질산이온 선택성 막전극)

  • Kim, Hwan-Ki;Shin, Doo-Soon
    • Journal of the Korean Chemical Society
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    • v.31 no.3
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    • pp.271-279
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    • 1987
  • A nitrate ion-selective PVC membrane electrode based on ammonia modified bakelite A-Ni$(NO_3)_2$ complex as ion exchanger was prepared. The electrode gave a linear response with a Nernstian slope of 60mV per decade within the concentration range $1{\sim}10^{-4}$ M $KNO_3$ but nonresponse to hydrogen ion and multivalent anions. The selectivity, response time and life time of the electrode were investigated and it was found that the electrode exhibited good selectivity for four univalent anions ($Cl^-,\;Br^-,\;I^-,\;{ClO_4}^-$). Analytical application to the determination of nitrate were also studied.

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Epinephrine-Selective Electrode Based on Lipophilic 1,3-Bisbridged Cofacial-calix[6]crown-5-ether

  • Yeo, Hee-Kyoung;Lee, Hyo-Kyoung;Nam, Kye-Chun;Jeon, Seung-Won
    • Bulletin of the Korean Chemical Society
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    • v.25 no.3
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    • pp.361-364
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    • 2004
  • The potentiometric response of electrode no. 4 based on 1,3-bisbridged cofacial-calix[6]crown-5-ether (IV) gave a sub-Nernstian (45.0 mV/decade) response and the best detection limit (-log $a_{ep}$ = 4.73) towards epinephrine. The responses are decreasing in the order of epinephrine > $K^+$, dopamine > $NH_4^+$ > norepinephrine > $Na^+$. It is remarkable that the proposed electrode shows the reasonable selectivity to epinephrine against other catecholamine neurotransmitters (dopamine and norepinephrine) as well as alkali metal ions.

Ferricyanide-Sensing Electrodes

  • Ihn, Gwon-Shik
    • Bulletin of the Korean Chemical Society
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    • v.7 no.1
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    • pp.36-38
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    • 1986
  • The Ferricyanide-sensing electrodes were prepared with $Ag_2S\;and\;Ag_3Fe(CN)_6$ (mole ratio 3:1-7:1). The 5:1 $(Ag_2S:Ag_3Fe(CN)_6)$ composition is superior to others in terms of potentiometric response, rapidity of response and reproducibility. Testing was done over the concentration range $10^{-1}M{\sim}10^{-6}M\; Fe(CN)_6^{3-}$ at pH 6.8 with constant ionic strength. The concentration-potential curve was linear and coincided with the Nernstian slope (19.7 mV/decade). Interfering ions were $I^-,\;Br^-,\; SCN^-\;and\;Fe(CN)_6^{4-}$ and the life time of this electrode was 3 weeks. This electrode could be used as the indicator electrode for measuring the ferricyanide and ferrocyanide.

A PVC Liquid Membrane Electrodes for the Determination of Norfloxacin (PVC 액체막 전극을 이용한 Norfloxacin의 정량)

  • 김동오;남수자;문현숙;정문모;허문회;김대병;안문규
    • YAKHAK HOEJI
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    • v.44 no.5
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    • pp.406-410
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    • 2000
  • The present method is to describe a potentiometric norfloxacin electrode system characterized by a membrane, based on the use of norfloxacin (NF) complex with ion-association reagents. These complexes were dissolved in DMSO, DMF acetonitrile or acetone and dispersed in plasticized poly(vinyl chloride) matrix. The picric acid complex electrode exhibited near-Nernstian response for NF in acetate buffer solution (pH 4.0) with a slope of 53.03 mV/decade. And linear response over the range of 10$^{-5}$ to 10$^{-3}$M solution of NE. The ingredients in tablet, capsule and biological important organic acids were not interfere.

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The Potentiometric Studies on the Effects of Various Functional Groups in Disiloxane as an Anion-Selective Ionophore

  • Jung, Hyo-Jin;Lee, Myong-Euy;Lim, Chae-Yun;Paeng, Ki-Jung
    • Bulletin of the Korean Chemical Society
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    • v.26 no.1
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    • pp.57-62
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    • 2005
  • The potentiometric responses for various anions are investigated with membrane electrode (membrane 1) based on 1,3-diethyl-1,3-dihydroxy-1,3-bis(2-dimethylaminomethyl ferrocenyl) disiloxane. The nitrate ion-selective electrode based on compound 1 gave a good Nernstian response of 58.18 mV per decade for nitrate with the detection limit of −e5.66 of log [NO3−e]. Compound 1 has all those functional groups and the other two compounds have less functional group of ferrocenyl or ferrocenyl and hydroxide, respectively. Even though, potentiometric response to anions was excellent at pH 5, the selectivity pattern for all three membrane electrode based on series of disiloxane is almost like Hofmeister sequence at pH 5. However, the membrane electrode 1-3 exhibited very different response to anions at pH 7. In this pH, NH2 is not protonated and ionophore may act as neutral carrier. Hydrogen bond may enhance the responsibility to hydrogen acceptors and intramolecular electro-active site may increase the permeability of analyte to ionophore in membrane.

The Potentiometric Performance of Mercury (II) Ion-Selective Electrode Based on Tetracycline Antibiotics

  • Baek, Jong-Gyu;Rhee Paeng, In-Sook
    • Journal of the Korean Electrochemical Society
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    • v.11 no.1
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    • pp.59-63
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    • 2008
  • Poly (vinylchloride) (PVC) membrane electrodes based on neutral carrier, tetracycline was prepared as an active sensor for Hg(II) ion, and tested in different contents of the potassium tetrakis (4-chlorophenyl) borate (KTpClPB) as lipophilic salt. Bis (2-ethylhexyl) sebacate (DOS), bis(l-butylpentyl) adipate (BBPA), 2-nitrophenyl octyl ether (NPOE) and dibutyl phthalate (DBP) were used as diverse plasticizing solvent mediators. This electrode shows excellent potentiometric response characteristics and display good linearity with log $[Hg^{+2}]$ versus EMF response, over a range of concentrations between $10^{-7}$ and $10^{-3}M$. With 30.8mV/decade Nernstian slope, the detection limit was $6.9{\times}10^{-9}M$ and the response time was less than 20s. The proposed electrode yields very good selectivity for mercury (II) ion over many cations such as alkali, alkaline earth, transition and heavy metal ions. And it shows a very stable potential values in a wide pH range. This reliable electrode prepared was kept at least a month without considerable alteration in their response to Hg (II) ion.