• 제목/요약/키워드: Electrochemical Determination

검색결과 199건 처리시간 0.024초

니켈(II)-거대고리 착물과 폴리 우레탄으로 변성한 이중 전극에서 에피네피린의 전기화학적 정량 (Electrochemical Determination of Epinephrine Using Doubly Modified Electrodes with Ni(II)-Macrocyclic Complex and Polyuretane)

  • ;조형화;권수경;이상학;배준웅
    • 전기화학회지
    • /
    • 제10권3호
    • /
    • pp.190-195
    • /
    • 2007
  • 본 연구는 뇨 속에 있는 에피네피린을 선택적으로 정량하기 위한 새로운 전기화학적 센서를 제작하고 그 특성을 연구한 것이다. 전극의 제작은 유리질 탄소전극에 촉매능이 있는 니켈(II)거대고리 착물을 전착시킨 후, 그 위에 생체적합성이 좋으며 음의 하전을 띤 polyuretane benzyl L-glutamate(PUBLG)로 막을 입힌 이중 폴리머 전극이다. 이 전극은 뇨 속에 있는 많은 방해물질에 대하여 좋은 선택성을 보였으며, 우수한 장기 안정성을 보였다. 최적 실험조건하에서 이 전극을 이용한 에피네피린의 정량범위는 $8.0\;{\times}\;10^{-7}\;M$에서 $2.0\;{\times}\;10^{-4}\;M$이고, 검출한계는 $1.0\;{\times}\;10^{-7}\;M$이다. 완충용액으로 5 배 희석한 뇨 시료에서 에피네피린의 회수율은 6 회 측정에서 $101.5({\pm}3.2)%$ 이었다.

Electrochemical Behaviors of Hydroquinone on a Carbon Paste Electrode with Ionic Liquid as Binder

  • Sun, Wei;Jiang, Qiang;Yang, Maoxia;Jiao, Kui
    • Bulletin of the Korean Chemical Society
    • /
    • 제29권5호
    • /
    • pp.915-920
    • /
    • 2008
  • In this paper the electrochemical behaviors of hydroquinone ($H_2Q$) were investigated on a carbon paste electrode using room temperature ionic liquid N-butylpyridinium hexafluorophosphate ($BPPF_6$) as binder (ILCPE) and further applied to $H_2Q$ determination. In pH 2.5 phosphate buffer solution (PBS), the electrochemical response of H2Q was greatly improved on the IL-CPE with a pair of well-defined quasi-reversible redox peaks appeared, which was attributed to the electrocatalytic activity of IL-CPE to the $H_2Q$. The redox peak potentials were located at 0.340 V (Epa) and 0.240 V (Epc) (vs. the saturated calomel electrode, SCE), respectively. The formal potential ($E^0$') was calculated as 0.290 V and the peak-to-peak separation (${\Delta}E_p$) was 0.100 V. The electrochemical parameters of $H_2Q$ on the IL-CPE were further calculated by cyclic voltammetry. Under the selected conditions the anodic peak current was linear with $H_2Q$ concentration over the range from $5.0\;{{\times}}\;10^{-6}$ to $5.0\;{\times}\;10^{-3}\;mol\;L^{-1}$ with the detection limit as $2.5\;{\times}\;10^{-6}\;mol\;L^{-1}$ (3$\sigma$ ) by cyclic voltammetry. The proposed method was successful applied to determination of $H_2Q$ content in a synthetic wastewater sample without the interferences of commonly coexisting substances.

Estimation of Energetic and Charge Transfer Properties of Iridium(III) Bis(2-phenylpyridinato-N,C2')acetylacetonate by Electrochemical Methods

  • Cha, Joeun;Ko, Eun-Song;Shin, Ik-Soo
    • Journal of Electrochemical Science and Technology
    • /
    • 제8권2호
    • /
    • pp.96-100
    • /
    • 2017
  • Iridium(III) bis(2-phenylpyridinato-$N,C^{2^{\prime}}$)acetylacetonate ($(ppy)_2Ir(acac)$), a green dopant used in organic light-emitting devices (OLEDs), was subjected to electrochemical characterization to estimate its formal oxidation potential ($E^{o^{\prime}}$), HOMO energy level ($E_{HOMO}$), electron transfer rate constant ($k^{o^{\prime}}$), and diffusion coefficient ($D_o$). The employed combination of voltammetric methods, i.e., cyclic voltammetry (CV), chronocoulometry (CC), and the Nicholson method, provided meaningful insights into the electron transfer kinetics of $(ppy)_2Ir(acac)$, allowing the determination of $k^{o^{\prime}}$ and $D_o$. The quasi-reversible oxidation of $(ppy)_2Ir(acac)$ furnished information on $E^{o^{\prime}}$ and $E_{HOMO}$, allowing the latter parameter to be easily estimated by electrochemical methods without relying on expensive and complex ultraviolet photoemission spectroscopic (UPS) measurements.

A Novel Sensor Based on Electropolymerization Poly(safranine) Film Electrode for Voltammetric Determination of 4-Nitrophenol

  • Liu, Xing-Yuan
    • Bulletin of the Korean Chemical Society
    • /
    • 제31권5호
    • /
    • pp.1182-1186
    • /
    • 2010
  • A novel poly(safranine)-modified electrode has been constructed for the determination of 4-nitrophenol (4-NP) in natural water sample. The electrochemical behavior of poly(safranine) film electrode and its electrocatalytic activity toward 4-NP were studied in detail by cyclic voltammetry (CV) and adsorptive linear stripping voltammetry (LSV). All experimental parameters were optimized and LSV was proposed for its determination. In optimal working conditions, the reduction current of 4-NP at this poly(safranine)-modified electrode exhibited a good linear relationship with 4-NP concentration in the range of $8.0{\times}10^{-8}$ to $4.0{\times}10^{-5}mol\;L^{-1}$. The detection limit was $3.0{\times}10^{-8}mol\;L^{-1}$. The high sensitivity and selectivity of the sensor were demonstrated by its practical application for the determination of trace amounts of 4-NP in natural water and fruit samples.

Alizarin Red S modified electrochemical sensors for the detection of aluminum ion

  • Chang, Seung-Cheol
    • 센서학회지
    • /
    • 제19권6호
    • /
    • pp.421-427
    • /
    • 2010
  • Alizarin Red S modified screen printed carbon electrodes were developed for the electrochemical detection of aluminum ion. The electrodes developed use screen-printed carbon electrodes(SPCEs) coupled with chemical modification with an organic chelator, Alizarin Red S(ARS), for aluminum ion detection in aqueous solution. For sensor fabrication ARS was directly immobilized on the surface of SPCEs using PVA-SbQ(The poly(vinyl alcohol) bearing stryrylpyridinium groups). Aluminum concentrations were indirectly estimated by amperometric determination of the non-complexed ARS immobilized on the electrodes, after its complexation with aluminum. The sensitivity of the sensor developed was $3.8\;nA{\mu}M^{-1}cm^{-2}$ and the detection limit for aluminum was $25\;{\mu}M$.