• Bulletin of the Korean Chemical Society
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• 제35권11호
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• pp.3175-3180
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• 2014

A potentiometric sensor based on the 1-benzyl-3-(4-nitrophenyl) thio-urea was synthesized and tested as an ionophore in PVC based membrane sensor towards $SCN^-$ ions. This membrane exhibits a linear stable response over a wide concentration range ($1.0{\times}10^{-5}$ to $1.0{\times}10^{-2}M$) with a slope of -59.2 mV/dec., a detection limit of ${\log}[SCN^-]=-5.05$, and a selectivity coefficient for thiocyanate against perchlorate anion of ${\log}K^{pot}_{SCN^-j}=-0.133$. The selectivity series of the membrane is as follows: $SCN^-$ > $ClO_4{^-}$ > $I^-$ > $NO_3{^-}$ > $HSO_3{^-}$ > $Cl^-$ > $HSO_4{^-}$ > $F^-$ > $CH_3COO^-$ > $HCO_3{^-}$ > $Br^-$ > $H_2PO_4{^-}$ > $SO{_3}^{2-}$ > $SO{_4}^{2-}$ > $CO{_3}^{2-}$. The proposed electrode showed good selectivity and a good response for the $SCN^-$ ion over a wide variety of other anions in pH 6.0 buffer solutions and has a fast response time of about < 5s. The influences of the membrane by pH, ionophore, and plasticizer were studied.

• Bulletin of the Korean Chemical Society
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• 제27권12호
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• pp.1985-1988
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• 2006

The polymeric membrane electrodes based on urea derivative as an ionophore were prepared and studied for the iodide-ion selective electrode. This membrane exhibits a linear stable response over a wide concentration range ($1.0\;{\times}\;10^{-5}\sim1.0\;{\times}\;10^{-2}$) with a slope of -57.7 mV/decade, a detection limit of log[$I^-$] = -5.63, and a selectivity coefficient for iodide against perchlorate anion (log$K^{pot}_{I^-,j}$ = -1.42). The selectivity series of the membrane gives the follow as $I^-$ > $SCN^-$, $Sal^-$ > $ClO_4^-$ > $NO_3^-$ > $Br^-$ > $NO_2^-$ > $Cl^-$ > $F^-$. The proposed electrode showed good selectivity and response for iodide anion over a wide variety of other anions in pH 5.0 buffer solutions.

• 한국안전학회지
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• 제10권4호
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• pp.47-59
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• 1995

The perchlorate, thiocyanate, and nitrate ion-selective PVC membrance electrode for measuring hazardous anion in waste water were developed by incorporating the quaternary ammonium salts as active material. Ion-selective characteristics in waste water were studied by the useful pH range, the selective coefficients to various interfering anions, and the stability of electrode potential. DBP was best as a plasticizer. The effect of the membrane thickness on the electrode characteristics was improved with decreasing the membrane thickness, but below the optimum membrane thickness the electrode exhibited an inverse trend. The electrode potential of perchlorate, thiocyanate, and nitrate electrode with TDDA, as active material, was stable within the pH range 4-11, 3-12, and 4-10 repectively. And the long-term potential stability of these electrodes were 3.0, 3.5, and 3.5 months respectively. The order of the selectivity coefficients was as shown below ; $ClO_4{^-}$ > $SCN^-$ > $I^-$ > $NO_3{^-}$ > $Br^-$ > $CN^-$ > $F^-$ > $Cl^-$ > $Ac^-$ > $H_2PO_4{^-}$, $SO_4{^-}$.

• 한국전기전자재료학회논문지
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• 제11권4호
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• pp.298-305
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• 1998

The PVC membrane electrode for measuring perchlorate ion was developed by incorporating various quaternary ammonium sallts. The effect of chemical structure, the content of active material, the kind of plasticizers, and the membrane thickness on the electrode characteristic such as the linear response range and Nernstian slope of the electrode were studied. It was obtained that the effect of the chemical structure of an active material on the electrode characteristics was improved with increasing the alkyl chain length of the quarternary ammonium salts in the ascending order of Aliquat 336P, TOAP, TDAP, and TDDAP. The optimum membrane composition was 9.09wt% of TDDAP, 30.3wt% of PVC, and 60.6wt% of plasticizer(DBP). And the optimum membrane thickness was 0.45mm at this composition. Under the above condition, the linear response range was $10^{-1}~1.2\times10^{-6}$M, and the detection limit was $5.1\times10^{-7}$M with the Nernstian slope of 57mV/decade of activity of perchlorate ion. The electrode potential was stable within the pH range from 4 to 11. The selectivity coefficient was as shown below: $SCN^->I^-NO_3^->Br^->ClO_3^->F^->Cl^->SO_4^{2-}$

• Bulletin of the Korean Chemical Society
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• 제25권10호
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• pp.1484-1488
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• 2004

The thiocyanate-selective PVC membrane electrodes based on 5,10,15,20-tetrakis(2,4,6-trimethylphenyl)-porphyrinatomanganese(III) chloride [Mn(TMP)Cl] and 5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrinatomanganese(III) chloride $[Mn(Cl_8TPP)Cl]$ as ion carriers were investigated. The effect of ionophores, membrane compositions, plasticizers, and solution pHs on the response characteristics were studied. The Mn(TMP)Cl as an ionophore shows the best potentiometric sensitivity with a slope of -58.7 mV/decade and a detection limit of $log[SCN^-]$ = -6.90, and selectivity for thiocyanate over strong hydrophobic interfering anions such as ${ClO_4}^-$ and salicylate. The potentiometric response is affected by the electronic effect of the substituents and solution pHs. The presence of substituents with electron donating and more liphophilic characters around the ligated metal center produces an improved response toward $SCN^-$.

• Bulletin of the Korean Chemical Society
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• 제31권6호
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• pp.1601-1608
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• 2010

A scandium(III) porphyrin-based fluoride-selective potentiometric sensor and its application in the analysis of hydrofluoric acid is described. Scandium(III) octaethylporphyrin, an ionophore recently developed for the optical fluoride sensor, was employed as a host molecule for the selective binding with fluoride in the plasticized PVC membrane. Nernstian response for $F^-$ between $10^{-4.6}$ to $10^{-1}$ M was observed at a glycine-phosphate buffer (pH 3.0). The selectivity pattern was observed as $F^-$, salicylate $\gg$ $SCN^-$ > $Cl^-$, $Br^-$, $NO_3{^-}$, $ClO_4{^-}$, which is consistent with the binding constant data measured in the plasticized PVC membrane based on a sandwich membrane method. This highly selective and reversible fluoride-sensitive electrode was employed for the analysis of hydrofluoric acid (HF). A disposable differential-type HF sensor was fabricated on the screen-printed electrode and demonstrated its ability to detect the neutral HF in the acidic solution.

• 멤브레인
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• 제3권3호
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• pp.126-135
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• 1993

감응물질로 제4급 암모늄염을 사용하여 PVC를 지지체로 과염소산이온의 농도 $10^{-6}M$까지 측정가능한 이온 선택성 전극을 제작하였다. 감응물질의 화학적 구조와 함량, 가소제의 종류 및 막 두께에 따른 선형응답 범위와 Nernst의 기울기 등 전극특성을 검토하여, 최적 막조건을 구한 다음 측정가능 pH범위와 여러 방해이온에 대한 선택계수를 비교 검토하였다. 과염소산 이온선택성 전극에서 감응물질의 화학적 구조 즉, 알킬기의 탄소고리수가 증가할수록 선형응답 범위 등 전극 특성은 Aliquat 336P, TOAP, TDAP 및 TDDAP의 순서로 좋아졌다. 가소제는 DBP가 가장 좋았고, 감응물질의 양은 최적 함량 이상에서 적을수록 좋았다. 최적 막 조성은 TDDAP 9.09, PVC 30.3 및 DBP 60.61wt%이었고, 막두께 0.45mm이었다. 이 조건에서 선형응답 범위 $10^{-1}~1.2 {\times} 10^{-6}M$, 검출한계 $5.1{\times}10^{-7}M$ 및 Nernst기울기 $57mV/pClO_4$이었다. 막전위는 pH 4~11 범위에서 pH의 영향을 받지 않았으며, 선택계수 서열은 다음과 같았다. $SCN^->I^->NO_3^->Br^->ClO_3^->F^->Cl^->SO_4^{2-}$

• 대한화학회지
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• 제41권12호
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• pp.653-660
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• 1997

Tetradecyltrimethylammonium chloride(TDTMACl)을 첨가한 실리콘러버-지지체 전극막은 생체시료중 염화이온의 측정시 보다 향상된 전기화학적 특성을 나타내기 위하여 사용되었다. 이때 최적화된 전극막의 조성비는 95.4 wt% 실리콘러버, 4.6 wt% TDTMACl이며 이 전극막의 pH 감응성은 pH 6-10 영역에서 무시할 수 있었다. 이들 전극막들의 염화이온에 대해 감응기울기는 10-300 mM 영역에서 -3.75 mV/decade로 이론적인 Nernstian 감응기울기에는 못 미쳤으나 살리실레이트 이온 등 다른 음이온에 대한 선택성은 매우 우수하였다: KpotCl,NO3=1.3, KpotCl,I=2.0, KpotCl,Sal=0.8, KpotCl,SCN=2.0, KpotCl,ClO4=0.8. 또한 실리콘러버-지지체 전극막은 PVC-지지체 전국막에 비해 고체상 전극표면에 대한 접착력이 우수하므로 CWE형 고체상 전극에 도입되었을 때 향상된 전극수명을 나타내었다. 이들 고체상 전극들은 35일까지 염화이온에 대한 감응기울기나 살리실레이트 이온에 대한 감응성에 변화없이 우수하게 작동함을 알 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제30권10호
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• pp.2303-2308
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• 2009

A thiocyanate poly(vinyl chloride) (PVC) membrane electrode based on [1,2-bis(diphenylphosphino)ethane]dihalopalladium( II), [(dppe)$PdX_2$, X = Cl ($L^1$), X = I ($L^2$)] as active sensor has been developed. The diiodopalladium complex, [(dppe)$PdI_2](L^2$) displays an anti-Hofmeister selectivity sequence: $SCN^-\;>\;I^-\;>\;{ClO_4}^-\;>\;Sal^-\;>\;Br^-\;>\;{NO_2}^-\;>\;{HPO_4}^-\;>\;AcO^-\;>\;{NO_3}^-\;>\;{H_2PO_4}^-\;>\;{CO_3}^{2-}$. The electrode exhibits a Nernstian response (-59.8 mV/decade) over a wide linear concentration range of thiocyanate ($(1.0\;{\times}\;10^{-1}\;to\;5.0\;{\times}\;10^{-6}$ M), low detection limit ($(1.1\;{\times}\;10^{-6}$ M), fast response $(t_{90%}$ = 24 s), and applicability over a wide pH range (3.5∼11). Addition of anionic sites, potassium tetrakis[p-chlorophenyl] borate (KTpClPB) is shown to improve potentiometric anion selectivity, suggesting that the palladium complex may operate as a partially charged carrier-type ionophore within the polymer membrane phase. The reaction mechanism is discussed with respect to UV-Vis and IR spectroscopy. Application of the electrode to the potentiometric titration of thiocyanate ion with silver nitrate is reported.

• 분석과학
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• 제10권6호
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• pp.427-432
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• 1997

도데실황산나트륨(SDS)이 수식된 유리탄소전극에 의해 철(III) 이온의 정량분석이 선택성 있게 제안되었다. 이것은 SDS와 $Fe^{3+}$의 정전기적 인력으로 착물이 형성되는 데 근거한 것이다. 철(III) 이온의 정량분석은 시차펄스전압전류법(DPV)에 의해 하였고, 그 정량분석을 위한 $(DS^-)_n-Fe^{3+}$의 환원 피크는 +0.466(${\pm}0.002$)volt (vs. Ag/AgCl)였다. 철(III) 이온의 정랑분석을 위한 검량선은 $0.50{\times}10^{-5}{\sim}10{\times}10^{-5}mol/L$의 농도 범위에서 얻었으며, 검출한계는 $0.14{\times}10^{-5}mol/L$였다. $Cu^{2+}$, $Ni^{2+}$, $Co^{2+}$, $Pb^{2+}$, $Zn^{2+}$ 및 $Mn^{2+}$는 철(III) 이온의 정량에 거의 영향을 미치지 않으나, $CN^- $ 및 $SCN^-$은 철(III) 이온의 정량을 크게 방해하였다.