• 제목/요약/키워드: Nernstian response

검색결과 79건 처리시간 0.023초

Thallium(I)-Selective Electrodes Based on Calix[4]pyrroles

  • 박경순;정성욱;이심성;김재상
    • Bulletin of the Korean Chemical Society
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    • 제21권9호
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    • pp.909-912
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    • 2000
  • Thallium(I) selective electrodes based on meso-alkyl substituted calix[4]pyrroles such as, meso-octamethyl-calix[4]pyrrole (L1), meso-octaethylcalix[4]pyrrole (L2) and meso-tetraspirocyclohexylcalix[4]pyrrole (L3) as sensor molecules have been pre pared and tested. The conditioned electrode (E4) incorporating L3gave best results with a wide working concentration range of 10-5.5 ~10-1 M near-Nernstian slope of 56.0 mV/decade of activity and detection limit of 10-6.0 M. This electrode exhibited a fast response time of 30 s and high selectivity over Na+ , K+ and other metal ions with only Ag+ interfering. The electrode works well in the pH range 2.0-11.0 and can be successfully employed for the determination of Tl+.This proposed electrode was also used as an indicator electrode in potentiometric titration of Tl+.

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.

A New Cone Shaped Asymmetrically Substituted Calix[4]arene as an ExcellentIonophore in Construction of Ag(I) ion-Selective Membrane Electrode

  • Ganjali, Mohammad Reza;Babaei, Leila Hajiagha;Taghvaei-Ganjali, Saeed;Modjallal, Atoosa;Sahmsipur, Mojtaba;Hosseini, Morteza;Javanbakht, Mehran
    • Bulletin of the Korean Chemical Society
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    • 제25권2호
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    • pp.177-181
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    • 2004
  • A PVC membrane electrode for silver ion based on a new cone shaped calix[4]arene (CASCA) as membrane carrier was prepared. The electrode exhibits a Nernstian response for $Ag^+$ over a wide concentration range ($1.0{\times}10^{-1}-8.0{\times}10^{-6}$M) with a slope of 58.2 {\pm}$ 0.5 mV per decade. The limit of detection of the sensor is $5.0{\times}10^{-6}$M. The sensor has a very fast response time (~5 s) in the concentration range of ${\leq}=1.0{\times}10^{-3}$ M, and a useful working pH range of 4.0-9.5. The proposed sensor displays excellent discriminating ability toward $Ag^+$ ion with respect to common alkali, alkaline earth, transition and heavy metal ions. It was used as an indicator electrode in potentiometric titration of $Ag^+$ with EDTA and in direct determination of silver ion in wastewater of silver electroplating.

Highly Selective Liquid Membrane Sensor Based on 1,3,5-Triphenylpyrylium Perchlorate for Quick Monitoring of Sulfate Ions

  • Ganjali, Mohammad Reza;Ghorbani, Maryam;Daftari, Azadeh;Norouzi, Parviz;Pirelahi, Hooshang;Dargahani, Hossein Daryanavard
    • Bulletin of the Korean Chemical Society
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    • 제25권2호
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    • pp.172-176
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    • 2004
  • A highly selective membrane electrode based on1,3,5-triphenylpyrylium perchlorate (TPPP) is presented. The proposed electrode shows very good selectivity for sulfate ions over a wide variety of common inorganic and organic anions. The sensor displays a nice Nernstian slope of -29.7 mV per decade. The working concentration ranges of the electrode is 1.0{\times}10^{-1}-6.3{\times}10^{-6} $M with a detection limit of $4.0{\times}10^{-6}$ M (480 ng per mL). The response time of the sensor in whole concentration ranges is very short (< 6 s). The response of the sensor is independent on the pH range of 2.5-9.5. The best performance was obtained with a membrane composition of 32% PVC, 59% benzyl acetate, 5% TPPP and 4% hexadecyltrimethylammonium bromide. It was successfully used as an indicator electrode for titration of sulfate ions with barium ions. The electrode was also applied for determination of salbutamol sulfate and paramomycine sulfate.

질산이온 선택성 피복선 전극의 제작 및 환경분석에의 응용 (Preparation of Coated-Wire Nitrate Ion Selective Electrode and its Application for Environmental Analysis)

  • 李龍根;金昌圭;朴廷泰;金京燮;黃圭子
    • 한국대기환경학회지
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    • 제1권1호
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    • pp.99-107
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    • 1985
  • A coated wire ion selective electrode for nitrate (nitrate-CWE_ was constructed using epoxy resin, ion exchanger and plasticizer as a polymer membrane. It's stility, the composition of a polymer membrane, the response characteristics, the selectivity were examined and applied to the environmental analysis. The nitrate-CWE was prepared using a copper wire, wihch was coated with epoxy resin being incorporated with the nitrate ion exchanger and plasticizer. The best composition of the polymer membrane for the nitrate-CWE was obtained by mixing epoxy resin, ion exchanger and plasticizer in the ratio of 2:1:0.4. The potential (56.3$\pm$0.5 mV) of stick form nitrate-CWE in this composition was close to that (59.2 mV) of Nernstian response. The detection limit for nitrate ion were found to the about $6 \times 10^{-5}M$ and the useful pH was 2.5 $\sim$ 10.3. Furthermore, the selectivity of iodide and perchrorate for the nitrage-CWE was also much improved compared with that for a liquid membrane nitrate electrode. The nitrate-CWE was used to determind $NO_x$ in stack gas. The results were in good agreement with those obtained either by electrode method or by the improved NEDA method within a relative error of 4.0%.

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UO22+ Ion-Selective Membrane Electrode Based on a Naphthol-Derivative Schiff's Base 2,2'-[1,2-Ethandiyl bis(nitriloethylidene)]bis(1-naphthalene)

  • Shamsipur, Mojtaba;Saeidi, Mahboubeh;Yari, Abdullah;Yaganeh-Faal, Ali;Mashhadizadeh, Mohammad Hossein;Azimi, Gholamhasan;Naeimi, Hossein;Sharghi, Hashem
    • Bulletin of the Korean Chemical Society
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    • 제25권5호
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    • pp.629-633
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    • 2004
  • A new PVC membrane electrode for $UO_2^{2+}$ ion based on 2,2'-[1,2-ethanediyl bis (nitriloethylidene)]bis(1-naphthalene) as a suitable ionophore was prepared. The electrode exhibites a Nernstian response for $UO_2^{2+}$ ion over a wide concentration range ($1.0{\times}10^{-1}-1.0{\times}10^{-7}$M) with a slope of 28.5 ${\pm}$ 0.8 mV/decade. The limit of detection is $7.0{\times}10^{-8}$M. The electrode has a response time of < 20 s and a useful working pH range of 3-4. The proposed membrane sensor shows good discriminating abilities towards $UO_2^{2+}$ ion with regard to several alkali, alkaline earth transition and heavy metal ions. It was successfully used to the recovery of uranyl ion from, tap water and, as an indicator electrode, in potentiometric titration of $UO_2^{2+}$ ion with Piroxycam.

폐수중 티오시안산이온을 측정하기 위한 계면활성제를 이용한 고분자 막전극 (The Polymer Membrane Electrode by Surfactants for Measuring Continuously Thiocyanate Ion in Wastewater)

  • 최종석;안형환;강안수;우인성;황명환
    • 한국안전학회지
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    • 제6권4호
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    • pp.13-20
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    • 1991
  • Ion-selective electrode responsive to the thiocynate ion prepared by using the quaternary ammonium salts as a active material and PVC as a membrane matrix. The effect of chemical structure and composition of active material, and the membrane thickness on the linear response. the detection limit, and Nernstian slope of the electrode studied. Under the above optimum conditions of membrane, the effect of pH and the selectivity coefficients to various interfering anions were compared and investigated. It was concluded that the functions of thiocynate ion-selective electrode(ISE) were closely related to the chemical structure of the quaternary ammonium salts. The linear response, and the detection limit of the electrode potential increased with the increase of the carbon chain length of the alkyl group in the quaternary ammonium salts in the ascending order of Aliquat 336T, TOAT, TDAT, and TDDAT. The optimum membrane thickness was 0.3mm. The electrode characteristics was better with the decrease of the concentration of active material, and the best concentration was 3 weight percent. The membrane potential was independent of the pH variation in the region from pH 2 to 12. The order of the selectivity coefficients is as follows:Cl $O_4$$^{[-10]}$$I^{[-10]}$ >N $O_3$$^{[-10]}$ >B $r^{[-10]}$$F^{[-10]}$ >C $l^{[-10]}$ >O $A_{c}$ $^{[-10]}$ 〓S $O_4$$^{2-}$.

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Sol-gel 법을 이용한 이성분 금속산화물 ($IrO_2-RuO_2$) pH 센서 (Binary Metal Oxide ($IrO_2-RuO_2$) pH Sensor Prepared by Sol-gel Method)

  • 이정란;오세림;한원식;홍태기
    • 한국응용과학기술학회지
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    • 제31권2호
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    • pp.190-196
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    • 2014
  • The sol-gel method was used to prepare binary metal oxide ($IrO_2-RuO_2$) pH sensor. The electrodes that mole percent compositions (mol%) of $IrO_2$ and RuO2 were 70:30 and 30:70 were selected. The characterizations of Nernstian response over pH range, response rate, interference on alkaline metals and reproducibility were investigated. Also the electroanalytical properties of these electrodes were evaluated in comparison with a commercial glass pH electrode. The composition of $IrO_2:RuO_2$ 70:30 mol% was chosen as better electrode formulation. The electrode was not susceptible to the action of interfering ions such as $Li^+$, $Na^+$ and $K^+$.

이온운반물을 사용치 않은 이온 선택성 막의 특성 (Response Characteristics of Ligand Free PVC Membranes)

  • 김영학;이지연;정문모;김은정;허문희;안문규
    • 분석과학
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    • 제10권6호
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    • pp.453-458
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    • 1997
  • poly(vinyl chloride)와 가소제만으로 된 막을 제조하여 몇 가지 염기성 의약품에 대한 감응 특성을 조사하여 보았다. 감응막을 초기의 전위값으로 빨리 되돌리기 위하여 황산으로 처리하였다. chlorpromazine을 정량할 때 2-nitrophenyl octyl ether을 사용한 막에서 $10^{-6}{\sim}10^{-3}M$, dioctyl PhenylPhosphnate, isododecyl phenylphosphate, dioctyl maleate 등의 경우 $10^{-6}{\sim}10^{-2}M$까지의 직선성 검량선을 얻을 수 있었고, 항생제, 당, 그리고 1급 아민화합물에 대한 감응선은 적게 나타났다.

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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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    • 제28권4호
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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.