• 대한화학회지
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• 제20권3호
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• pp.206-211
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• 1976

비수용액 에틸렌디아민 중에서 산-알칼리의 전위차 중화 적정 이론을 고찰하여 실험한 결과 이론과 잘 일치하였다.

• Journal of Electrochemical Science and Technology
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• 제2권3호
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• pp.143-145
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• 2011

Metal-binding antibiotics are very attractive choices as cation selective ionophores. The ability of tetracycline (TC) antibiotics to bind to metal ions has obtained much attention. TCs exhibit the potentiometric performance changes for various cations dependant on several experiment conditions. In this report, we investigated the potentiometric performance changes of TC as the modification of TC's possible metal binding site. We found that the selectivity alter with the blocking main binding site of ionophores for cations. And, additionally it is possible to control the selectivity of sensors with chemical modification of ionophores.

• Bulletin of the Korean Chemical Society
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• 제33권4호
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• pp.1247-1252
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• 2012

In this paper, a potentiometric sensor based on polyaniline conducting polymer for potentiometric determination of Cr (VI) ions is reported. Polyaniline was synthesized electrochemically (cyclic voltammetry method) onto a micro pencil graphite electrode (0.7 mm diameter) in the presence of HCl and diphenylcarbazide (termed as (PGE/PAni/DPC). Some initial experiments were performed in order to find out the optimized conditions for preparation of the introduced Cr (VI) sensor electrode. The plot of E vs. log [Cr (VI)], showed a linear response in the range from $1.0{\times}10^{-6}$ to $1.0{\times}10^{-1}$ M. High repeatability with the detection limit of $8.0{\times}10^{-7}$ M was obtained.

• Bulletin of the Korean Chemical Society
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• 제26권1호
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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.

• Bulletin of the Korean Chemical Society
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• 제29권9호
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• pp.1774-1780
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• 2008

New PVC based polymeric membrane electrodes (PME) and coated glassy carbon electrodes (CGCE) based on synthesized Schiff base complexes of Co(III); [Co(Salen)$(PBu_3)_2$]$ClO_4$, [Co($Me_2$Salen)$(PBu_3)_2$]$ClO_4$, [Co(Salen)$(PBu_3)H_2O$]$ClO_4$; as anion carriers for potentiometric determination of $ClO_4\;^-$were studied. The PME and also CGCE electrodes prepared with [Co(Me2Salen)$(PBu_3)_2$]$ClO_4$ showed excellent response characteristics to perchlorate ions. The electrodes exhibited Nernstian responses to $ClO_4\;^-$ ions over a wide concentration range with low detection limits ($1.0 {\times} 10^{-6}\;mol\;L^{-1}$ for PME and $9.0 {\times} 10^{-7}\;mol\;L^{-1}$ for CGCE). The electrodes possess fast response time, satisfactory reproducibility, appropriate lifetime and, most importantly, good selectivity toward $ClO_4\;^-$ relative to a variety of other common inorganic anions. The potentiometric response of the electrodes is independent of the pH in the pH range 2.5-8.5. The proposed sensors were used in potentiometric determination of perchlorate ions in mineral water and urine samples. The interaction of the ionophore with perchlorate ions was shown by UV/Vis spectroscopy.

• Bulletin of the Korean Chemical Society
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• 제20권5호
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• pp.581-586
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• 1999

A series of polyethers containing the thiazole or oxazole subcyclic moiety have been synthesized. Reaction of 2-aryl-4-hydroxymethylthiazole with tetra- and pentaethylene glycol di-p-tosylate in THF provided corresponding α,ω-bis[2'-aryl-4'-methylthiazole]polyethylene glycol in good yields. Similar treatment of 2-phenyl-4-hydroxymethyloxazole 7 and 2-phenyl-5-hydroxymethyloxazole 8 with tetraethylene glycol di-p-tosylate yielded the corresponding 1,13-bis [2'-phenyl-4'-methyloxazole]tetraethylene glycol 16 and 1,13-bis[2'-phenyl-5'-methyloxazole]tetraethylene glycol 17 in 69 and 43% yields in respectively. The potentiometric properties of PVC-based ion selective membranes containing 66 wt% o-nitrophenyloctyl ether (NPOE) and 4 wt% polyethers 9-17 have been examined. The membranes containing thiazole and oxazole polyether derivatives exhibited high selectivity toward silver (I) ion. It was observed that the response slopes of the electrodes to silver ion vary with the length of polyether chain linking two thiazole subcyclic moiety. Potentiometric data suggest that the number of ether units, CH2OCH2, for phenylthiazole derivatives be greater than 5 to result in near-Nernstian response. However, the response behaviors of the membrane electrodes based on phenyloxazole podands 16 and 17, which have different orientation, were correspondingly similar to those of the electrodes based on phenylthiazole podands 9 and 10. On the other hand, the ISEs based on thiazole polyether derivatives with different terminal substituents, e.g., phenyl 10, naphtyl 14, and thienyl 15, except that with pyridyl 12, exhibited little difference in their potentiometric properties.

• 한국식품과학회지
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• 제36권6호
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• pp.885-892
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• 2004

본 실험에서는 성장기용 조제식에 함유된 유지를 대상으로 전위차 적정법 및 뷰렛 적정법에 의한 과산화물가를 측정하고 그 측정불확도를 비교하여 산정하였다. GUM(Guide to the expression of uncertainty in measurement) 및 Draft EURACHEM/CITAC Guide의 이론에 기초하여 측정불확도를 구하였으며, 불확도 인자로서 적정액의 농도, 시료량 및 적정량 등이 작용하였다. 뷰렛적정에 의한 과산화물가 측정값과 확장불확도는 $2.05{\pm}0.17\;meq/kg$ 으로 표현되었으며, 전위차적정에 의한 경우는 $1.96{\pm}0.07\;meq/kg$ 으로 표현되었다. 적정과정에서의 측정불확도가 전체불확도의 대부분을 차지하였으며, 전위차적정법에 의한 측정불확도는 뷰렛적정법에 의한 경우보다 낮게 나타나 과산화물가가 낮은 시료의 측정시에 바람직한 측정방법으로 사료되었다.

• Journal of Microbiology and Biotechnology
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• 제14권4호
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• pp.698-706
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• 2004

$\beta$-Lactam antibiotics such as penicillin G, amoxicillin, and ampicillin were determined by a potentiometric biosensor system which exploited penicillinase immobilized on Immobilon cellulose nitrate membrane and a flat-bottomed pH electrode-as the biological component and transducer. The optimum reaction buffer for maximum sensitivity was found as 2 mM of sodium phosphate buffer (pH 7.2). The detection limit of the biosensor could be extended to 1 $\mu{M}$ of the analytes by increasing the enzyme loading for immobilization to 100 units/$m\ell$. The model samples spiked with each of the standard penicillins were measured for their biosensor responses and HPLC peak area, resulting in the relative responses of 82.1-103.5% and 79.5-106.1% for the biosensor method along with HPLC analysis, respectively. This result showed a good precision of the current biosensor method for screening the penicillin compounds.

• 분석과학
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• 제8권4호
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• pp.691-698
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• 1995

The complexation of platinum and palladium with synthetic polyelectrolytes was studied. The successive and overall stability constants of Pd(II) with PEI and 2PVP were obtained by potentiometric titration. Because of the slow equilibrium time, the potentiometric titrations were performed using the home-made automatic titrator in order to analyze the complexations according to the modified Bjerrum method. The complex formation constant of Pt(IV) with 2PVP, measured by differential pulse polarography, was calculated from the peak currents that were obtained in non-complexing media and in solution containing 2PVP.

• 약학회지
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• 제45권1호
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• pp.29-33
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• 2001

A method for the determination of anionic drug, mefenamate with ion-selective electrode using Fe(II)-1,10-phenanthroline chelate as a counter ion was developed. Benzyl nitrophenyl ether (BNPE) plasticized membrane was more selective and sensitive than the other tested membranes. This membrane electrode exhibits a linear response for 10$^{-2}$ M~5 $\times$ 10$^{-5}$ M of mefenamic acid with a slope of -61.4 mV/dec. in borate buffer solutions (pH 9.0). Potentiometric selectivity measurements revealed negligible interferences from various organic and ionorganic anions. Direct potentiometry and potentiometric titration method of mefenamic acid in capsule preparations are presented and compared.