• Title, Summary, Keyword: ion-selective electrode

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Silicone Rubber Blended with Polyurethane as the Matrix for Ion-Selective Membrane Electrodes

  • Lee, Hyun Jung;Rho, Kyung Lae;Kim, Chang Yong;Oh, Bong Kyun;Cha, Geun Sig;Nam, Hakhyun
    • Analytical Science and Technology
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    • v.8 no.4
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    • pp.623-630
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    • 1995
  • Silicone rubber-based sodium-selective membranes are developed for solid-state ion sensors. It was shown that the potetiometric performance of SR-based membranes are greatly dependent on the type of neutral carriers employed; among the three ionophores, N,N,N',N'-tetracyclohexyl-1,2-phenylenedioxydiacetamide (ETH 2120), bis[(12-crown-4)methyl]dodecylmethylmalonate (D12C4DMM) and monensin methyl ester (MME), examined, only ETH 2120 was compatible with the SR-based matrix. Addition of about 20 wt% plasticizer to the SR-based matrix provided the resulting membranes with potentiometric properties essentially equivalent to those of the corresponding PVC-based membranes. Owing to the strong adhesive strength of SR-based membranes, the CWEs coated \vith those membranes exhibited long lifetime with conventional electrode-like performance. Blending of PU into the SR matrix increased the lifetime of CWEs from two weeks to one month.

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Construction of Carbon Paste Coated Wire Ion-Selective Electrode for Chloride and Its Application to Environmental Water Analysis

  • Yong-Kyun Lee;Soo Kil Rhim;Kyu-Ja Whang
    • Bulletin of the Korean Chemical Society
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    • v.10 no.6
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    • pp.485-488
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    • 1989
  • A carbon paste coated-wire ion-selective electrode for chloride (carbon chloride-CWE) was constructed using epoxy resin, ion-exchanger and carbon powder as a polymer membrane. Its utility, the composition of a polymer membrane, the response characteristics, and the selectivity were examined and applied to the environmental water analysis. The carbon chloride-CWE was prepared using a silver wire, which was covered with silver chloride and then coated with epoxy resin into which chloride ion-exchanger and carbon powder were previously incorporated in advance. The response of the carbon chloride-CWE was Nernstian for $1.0{\times}10^{-2}-2{\times}10^{-5}$ M chloride and the useful pH range from $10^{-2} M Cl- to 10^{-4} M Cl^-$ was 3.0-9.0. Furthermore, the selectivity of chloride over iodide, bromide, and cyanide was much improved compared with those for a solid state epoxy body chloride electrode and a liquid membrane chloride electrode. The carbon chloride-CWE was applied to determine Cl^-$ in tap and ground water. The obtained results were in good agreement with those by the established methods such as spectrophotometric or other chloride-selective electrode methods.

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Lead(II)-selective Polymeric Electrode Using a Schiff Base Complex of N,N'-Bis-thiophene-2-ylmethylene-ethane-1,2-diamine as an Ion Carrier

  • Jeong, Tae-Jun;Jeong, Dae-Cheol;Lee, Hyo-Kyoung;Jeon, Seung-Won
    • Bulletin of the Korean Chemical Society
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    • v.26 no.8
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    • pp.1219-1224
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    • 2005
  • We prepared lead ion-selective PVC membranes that were based on N,N'-bis-thiophene-2-ylmethylene-ethane-1,2-diamine as a membrane carrier. The membrane electrode has a linear dynamic range between 1.0 ${\times}$ $10^{-5}$ and 1.0 ${\times}$ $10^{-1}$ M with a Nernstian slope of 29.79 mV per decade, and its detection limit was 2.04 ${\times}$ $10^{-6}$ M at room temperature. The potentiometric response is independent of the pH of the solution in the pH range of 5-7. The proposed electrode revealed good selectivity and response for $Pb^{2+}$ over a wide variety of other metal ions in pH 5.0 buffer solutions, and there was good reproducibility of the base line on the subsequent measurements. The membrane electrode has a relatively fast response time, satisfactory reproducibility and a relatively long life time.

Application of a. Strip Ion-Selective Electrode Sensor for Hydroponic Nutrient Solution Analysis - NO3 Analysis - (양액의 영양분 분석을 위한 Strip형 이온선택성전극 센서 의 응용 -NO3 이온 분석 -)

  • 김기영
    • Journal of Biosystems Engineering
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    • v.28 no.4
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    • pp.335-342
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    • 2003
  • A simple disposable thick-film potentiometric strip has been developed and evaluated for hydroponics application. The strip consisted of low ion-selective electrodes (ISE) fabricated by screen-printing technology. The electrochemical responses of ion sensors for nitrate, ammonium, potassium, and magnesium were measured with specially designed 16-channel low voltage signal transducers. The analytical characteristics of the sensors were comparable with those of conventional ISE sensors. The thick-film sensors exhibit linear relationships over five concentration decades. The concentration of N $O_3$ - ion in standard solution can be determined by direct potentiometric measurements without any conditioning before measurements. However, measurement of $K^{+}$, N $H_4$$^{+}$, and $Mg^{2+}$ ionic concentrations in nutrient solutions seems not feasible.

Pilymeric Membrane Sodium Ion-Selective Electrodes Based on Calix[4}arene Triesters

  • Kim, Yun Deok;Jeong, Hae Sang;Gang, Seong Ok;Nam, Gye Cheon;Jeon, Seung Won
    • Bulletin of the Korean Chemical Society
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    • v.22 no.4
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    • pp.405-408
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    • 2001
  • New lipophilic triesters of calix[4]arene and calix[4]quinone are investigated as sodium ion-selective ionophores in poly(vinyl chloride) membrane electrodes. For an ion selective electrode based on calix[4]arene triester I, the linear response is 1 ${\times}$10-3.5 to 1 ${\times}$ 10-1 M of Na+ concentrations. The selectivity coefficients for sodium ion over alkali metal and ammonium ions are determined. The detection limit (logaNa+ = -4.50) and the selectivity coefficient (logKNa+,K+pot = -1.86) are obtained for polymeric membrane electrode containing calix[4]arene triester I.

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Polymeric Lead(II)-selective Electrode Based on N,N'-Bis-thiophen-2-ylmethylene-pyridine-2,6-diamine as an Ion Carrier

  • Kim, Hee-Cheol;Lee, Hyo-Kyoung;Choi, A-Young;Jeon, Seung-Won
    • Bulletin of the Korean Chemical Society
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    • v.28 no.4
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    • pp.538-542
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    • 2007
  • Polymeric electrodes for lead ion based on N,N'-bis-thiophen-2-ylmethylene-pyridine-2,6-diamine as an ion carrier were prepared. The membrane electrode (m-3) containing o-NPOE as a plasticizer and 50 mol% additive of ionophore gives an excellent Nernstian response (29.59 mV/decade) and the limit of detection of ?log a (M) = 5.74 to Pb2+ in Pb(NO3)2 solution at room temperature. The prepared electrode provided good sensitivity and outstanding selectivity and response for Pb2+ over a wide variety of other metal ions in pH 7.0 buffer solutions. The good sensitivity and selectivity towards lead ion are attributed to the strong complexation of lead ion to N,N'-bis-thiophen-2-ylmethylene-pyridine-2,6-diamine which has geometrically the proper cavity to coordinate to the ligand.

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.

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.

Surface Renewable Hydrogen Ion-Selective Polymeric Composite Electrode Containing Iridium Oxide

  • Quan, Hongmei;Kim, Won;Chung, Koo-Chun;Park, Jong-Man
    • Bulletin of the Korean Chemical Society
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    • v.26 no.10
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    • pp.1565-1568
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    • 2005
  • A surface renewable pH electrode was prepared by utilizing composite electrode technique. Iridium oxide micro-fine particles was prepared by hydrolysis of $(NH_4)_2IrCl_6$ at elevated temperature. The iridium oxide particles were mixed with well-dispersed carbon black and then filtered. The mixture was suspended in DMF containing PVC as a binder. The mixture was precipitated rapidly by adding large amount of water. The precipitate was ground and pressure-molded to iridium oxide composite electrode material. The electrode showed linear response between pH 1-13 with 50 to 60 mV/pH slope. The electrode maintained the pH response without appreciable slope drift for 170 days if stored in deionized water. The electrode surface can be renewed reproducibly by simple grinding process whenever contaminated or deactivated.

Comparison of Selective Removal of Nitrate Ion in Constant Voltage and Constant Current Operation in Capacitive Deionization (축전식 탈염에서 정전압과 정전류 운전에 따른 질산 이온의 선택적 제거율 비교)

  • Choi, Jae-Hwan;Kim, Hyun-Ki
    • Korean Chemical Engineering Research
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    • v.53 no.3
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    • pp.269-275
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    • 2015
  • The adsorption characteristics of ions were evaluated for the nitrate-selective carbon electrode (NSCE) in accordance with power supply methods. The NSCE was fabricated by coating the surface of a carbon electrode with anion-exchange resin powders with high selectivity for the nitrate ion. Capacitive deionization (CDI) experiments were performed on a mixed solution of nitrate and chloride ion in constant voltage (CV) and constant current (CC) modes. The number of total adsorbed ions in CV mode was 15% greater than that in CC mode. The mole fraction of adsorbed nitrate ion showed the maximum 58%, though the mole fraction was 26% in the mixed solution. This indicates that the fabricated NSCE is highly effective for the selective adsorption of nitrate ions. The mole fraction of adsorbed nitrate was nearly constant value of 55-58% during the adsorption period in CC mode. In the case of CV mode, however, the values increased from the initial 30% to 58% at the end of adsorption. We confirmed that the current supplied to cell is important factor to determine the selective removal of nitrate.