• 제목/요약/키워드: Potentiometric

검색결과 239건 처리시간 0.02초

Potentiometric studies on Ternary Complexes of Some Heavy Metal lons Containing N-(2-Acetamido)-iminodiacetic and Amino Acids

  • Mahmoud, Mohamed Rafat;Maher Mohamed Ahmed -Hamed;Ahmed, Iman Tawfik
    • Archives of Pharmacal Research
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    • 제16권1호
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    • pp.78-81
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    • 1993
  • Solution equilibria of the thmary systems $UO_2(II)$, La(III), Ce(III)-N-(2-acetamido)-iminodiacetic acid and dicarboxylic amino acids are studied potentiometrically. The formation of 1:1:1 mixed ligand complexes are inferred from the potentiometric titration curves. The formation constants of the different binary and thmary complexes in such system are evaluated at t=$24\pm{0.1}^\circ{C}\;and\;\mu=0.1\;mol\;dm^{-3}(kNO_3)$. It is deduced that the temary complex is more stable than the corresponding binary amino acid anion complex. Moreover, the order og stability of the binary or temary complexes in terms of nature of amino acid and metal ion is investigated and discussed.

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Investigation of Simple Electrochemical Conditions for Generation of Ozonized Water

  • Tanaka, Mutsumi;Kim, Han-Joo;Kim, Tae-Il;Park, Soo-Gil
    • 전기화학회지
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    • 제11권3호
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    • pp.135-140
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    • 2008
  • An electrochemical generation of ozonized water was investigated by using ${\beta}-PbO_2$ as an anode and tap water as an anolyte. According to the potentiometric ozone detection which utilizes potential differences arisen from a chemical reaction of ozone and iodide, increasing tendency of ozone concentration on electrolysis time could be observed to show the maximum value of 8 ppm at an electrolysis time of 10 min. Ozone could be generated promptly even at an electrolysis time of 10 sec., suggesting great advantages of this electrochemical process in terms of simplicity and readiness that might be applied directly to practical uses including medical and/ or food industries. Influences of electrolysis on the properties and surface conditions of a $PbO_2$ electrode were also discussed from the results of cyclic voltammetry, scanning electron microscope, and X-ray diffractometer.

폴리톨루이딘 합성 및 전기화학적 특성분석

  • 박수범;이성주;김은옥
    • 대한화학회지
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    • 제46권3호
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    • pp.225-228
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    • 2002
  • 폴리아닐린에 전자주게기(-CH3)를 치환하여 전자효과(electronic effect) 와 입체장애효과(steric effect)를 확인하기 위하여 폴리아닐린 유도체인 폴리톨루이딘(POT)1을 화학적 및 전기화학적으로 합성한 결과 입체장애효과가 더 우세하였다. 순환전압 전류법(Cyclic Voltammetry)과 전위차벗김 분석법(Constant Current Potentiometric Stripping Analysis)을 사용한 결과 POT의 IP는 4.95eV, EA는 3,24eV, Eg는 1.71eV임을 확인하였다.

8-Hydroxyquinoline 誘導體에 關한 硏究 5-Acetyl-8-Hydroxyquinoline의 酸解離定數 (Study of 8-Hydroxyquinoline Derivatives. The Acid Dissociation Constants of 5-Acetyl-8-Hydroxyquinoline)

  • 이동형
    • 대한화학회지
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    • 제9권1호
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    • pp.33-36
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    • 1965
  • 5-Acetyl-8-hydroxyquinoline 의 酸解離定數를 $25^{\circ}C({\mu}$=0.1)에서 分光光度法과 pH滴定法에 依하여 測定하였다. 두 方法에 의하여 얻은 $pK_1$은 近似하게 一致하였으며 pK값은 8-hydroxyquinoline의 該當 pK값보다 작다. 그것은 acetyl group의 芳香族環에 대한 電子吸引性에 基因한 結果라고 생각한다.

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Potentiometric Sensor for the Determination of Dibucaine in Pharmaceutical Preparations and Electrochemical Study of the Drug with BSA

  • Ensafi, Ali A.;Allafchian, A.R.
    • Bulletin of the Korean Chemical Society
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    • 제32권8호
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    • pp.2722-2726
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    • 2011
  • Plasticized poly(vinyl chloride), PVCs, with different membrane compositions tested for use in the construction of an ion-selective sensor for the determination dibucaine. A prepared membrane with dioctyl phthalate-PVC and ion-pair of N-(1-naphthyl)ethylenediamine dihydrochloride-tetraphenyl borate had a good potential to acts as a potentiometric sensor for the analysis of dibucaine. A linear relationship was obtained between potential and logC varying between $1.0{\times}10^{-6}$ and $1.0{\times}10^{-2}$ M dibucaine with a good repeatability and reproducibility. The sensor was applied for the determination of the drug in pharmaceuticals and biological fluids such as plasma and urine samples with satisfactory results. The drug electrode has also been used to study the interaction of bovine serum albumin (BSA) with dibucaine. The saturated quantities of dibucaine binding were 13.04, 5.30 and 9.70 mol/mol in 0.01, 0.02 and 0.1% of protein, respectively.

IEEE 1451.4를 이용한 전자혀 시스템의 표준화 방안 (The way to standardize electronic tongue system using IEEE 1451.4)

  • 김동진;김정도;변형기;함유경;한동원
    • 센서학회지
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    • 제14권6호
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    • pp.444-454
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    • 2005
  • The IEEE 1451.4 standards defines an architectural model for interfacing smart transducers for sensors & actuators. This standard allows analogue transducers to communicate their identification and calibration data in a digital format. A digital format is called the TEDS (transducer electronic data sheet). However, the standard template TEDS of IEEE 1451.4 do not supports sensors to use in electronic tongue system, such as arrayed-potentiometric and voltametric sensors. In this paper, a solution to standardize sensors for E-Tongue (electronic tongue) and electronic tongue systems is presented.

전위차 부식촉진법을 이용한 철근 콘크리트의 내부식성 예측을 위한 실험 연구 (An Experimental Study on the Prediction of Corrosion Resistance of Reinforced Concrete Using Accelerated Potentiometric Corrosion Test)

  • 오병환;조윤구;차수원;정원기
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1996년도 봄 학술발표회 논문집
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    • pp.71-76
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    • 1996
  • Recently, large scale concrete structures exposed to severe environment are increasingly built in various locations. The corrosion may affect severely the durability and service life of such a concrete structure. It is, therefore, necessary to develop durable concrete to enhance the corrosion resistance. The corrosion resistance of concrete can be identified through accelerated corrosion test. The purpose of the present paper is, therefore, to devise a reasonable and accurate method to predict the amount of corrosion of reinforcing steels. The proposed method which is basically based on the concept of Faraday's Law, determines the corroded amount of a re-bar according to accelerated corrosion time. The corrosion is accelerated by employing the potentiometric corrosion test arrangement. The effects of admixtures in concrete including fly ash and silica fume have been also studied to explore the relative corrosion resistance of concrete.

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Evaluation of Two Types of Biosensors for Immunoassay of Botulinum Toxin

  • Choi, Ki-Bong;Seo, Won-Jun;Cha, Seung-Hee;Choi, Jung-Do
    • BMB Reports
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    • 제31권1호
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    • pp.101-105
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    • 1998
  • Immunoassay of botulinum toxin (BTX) B type was investigated using two typed of biosensors: light addressable potentiometric sensor (LAPS) and surface plasmon resonance (SPR) sensor. Urease-tagged and immuno-filtration capture method have been used for LAPS. Tag-free and direct binding real-time detection method have been used for SPR sensor. The detection limit of sandwich assay format with LAPS was 10 ng/ml, which was the lowest among methods tested. SPR has the advantage of being more convenient because tag-free direct binding assay can be used and reaction time was reduced, regardless of low sensitivity. This result shows that sandwich assay format with LAPS can be used as an alternative method of BTX mouse bioassay which is known as the most sensitive method for the detection of BTX.

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Characterization of Functional Groups of Protonated Sargassum polycystum Biomass Capable of Binding Protons and Metal Ions

  • Yun, Yeoung-Sang
    • Journal of Microbiology and Biotechnology
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    • 제14권1호
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    • pp.29-34
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    • 2004
  • Biosorption technology is recognized as an economically feasible alternative for the removal and/or recovery of metal ions from industrial wastewater sources. However, the structure of biosorbents is quite complex when compared with synthetic ion-exchange resins, which makes it difficult to quantify the ion-binding sites. Accordingly, this report describes a well-defined method to characterize the pK values and numbers of biomass functional groups from potentiometric titration data. When the proposed method was applied to Sargassum polycystum biomass as a model biosorbent, it was found that the biomass contained three types of functional groups. In addition, the carboxyl group (pK=$3.7{\pm}0.09$) was found to be the major binding sites ($2.57{\pm}0.06 mmol/g$) for positively-charged heavy-metal ions.