• Bulletin of the Korean Chemical Society
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• 제30권7호
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• pp.1470-1474
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• 2009

Thermal and photochemistry of methyl iodide ($CH_3I)\;adsorbed\;on\;D_2O$ ice film on Cu(111) at 100 K were studied using temperature-programmed desorption (TPD) time-of-flight mass spectrometry (TOF-MS), X-ray and ultraviolet photoelectron spectroscopies. On the basis of TPD, multilayer and monolayer $CH_3I$ molecules desorb from $D_2O$ ice layer at 120 and 130 K, respectively. Photo-irradiation at 100 K exhibits dramatic changes in the TPD and I $3d_{5/2}\;XPS\;of\;CH_3I$ on ice film, due to a dramatic dissociation of $CH_3I$. The dissociation is likely activated by solvated electrons transferred from the metal substrate during photo-irradiation. No other photo-initiated reaction products were found within our instrumental detection limit. During photo-irradiation, the $CH_3I$, $CH_3$ and I could be trapped (or solvated) in ice film by rearrangement (and self-diffusion) of water molecules. A newly appeared parent molecular desorption peak at 145 K is attributed to trapped $CH_3I$. In addition, the $CH_3$ and I may diffuse through ice and chemisorb on Cu(111), indicated by TPD and I $d_{5/2}$ XPS taken with photo-irradiation time, respectively. No molecular ejection was found during photo-irradiation at 100 K. The work functions for $CH_3I/Cu(111),\;D_2O/Cu(111)\;and\;CH_3I/D_2$O/Cu(111) were all measured to be about 3.9 eV, 1.0 eV downward shift from that of clean Cu(111).

• Bulletin of the Korean Chemical Society
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• 제32권9호
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• pp.3400-3404
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• 2011

A new rhodamine B-coumarin conjugate (1) capable of recognizing both $Cu^{2+}$ and $Fe^{3+}$ using two different detection modes have been designed and synthesized. The metal ion induced optical changes of 1 were investigated in $CH_3CN-H_2O$ (1:1, v/v, HEPES 50 mM, pH = 7.0) solution. Sensor 1 exhibits selective colorimetric recognition of $Cu^{2+}$ and fluorescent recognition of $Fe^{3+}$ with UV-vis and fluorescence spectroscopy, respectively. Moreover, both of the $Cu^{2+}$ and $Fe^{3+}$ recognition processes are observed to be barely interfered by other coexisting metal ions.

• Bulletin of the Korean Chemical Society
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• 제34권1호
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• pp.159-163
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• 2013

A new Rhodamine B hydrazide hydrazone 1 has been synthesized and investigated as a colorimetric and fluorescent "off-on" sensor for the recognition of $Cu^{2+}$ in $CH_3CN/H_2O$ (1:1, v/v, HEPES 10 mM, pH = 7.0) solution. Sensor 1 displayed highly selective, sensitive and rapid recognition behavior toward $Cu^{2+}$ among a range of biologically and environmentally important metal ions. Sensor 1 bind $Cu^{2+}$ via a 1:1 stoichiometry with an association constant of $1.92{\times}10^6\;M^{-1}$, and the detection limit is evaluated to be $7.96{\times}10^{-8}\;M$. The $Cu^{2+}$ recognition event is reversible and is barely interfered by other coexisting metal ions.

• 분석과학
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• 제25권3호
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• pp.171-177
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• 2012

Luminol-$H_2O_2$-Cu(II) 시스템을 이용한 화학발광법을 사용하여 방향족 아미노산인 트립토판, 타이로신 및 페닐알라닌의 정량분석을 하였다. 세 종류의 방향족 아미노산(트립토판, 타이로신, 페닐알라닌)을 luminol-$H_2O_2$-Cu(II) 시스템에 첨가하였을 때 아미노산이 존재하지 않을 때보다 화학발광세기가 더욱 증가하는 현상을 관찰하였으며, 이러한 현상을 이용하여 각 방향족 아미노산을 정량분석 하였다. 방향족 아미노산의 최적분석 조건을 조사하기 위하여, Cu(II) 이온 촉매에 의한 루미놀과 과산화수소의 화학발광반응에 미치는 아미노산의 반응속도론적 영향을 조사하였고 과산화수소와 Cu(II) 이온의 농도 그리고 pH와 완충용액의 영향을 조사하였다. 루미놀 화학발광 시스템의 최적 분석조건 하에서 수용액 중의 방향족 아미노산 정량분석을 위해 얻은 검정곡선에서 직선성이 성립하는 농도 범위는 각각 트립토판은 $1.0{\times}10^{-6}{\sim}2.0{\times}10^{-5}\;M$, 타이로신은 $1.0{\times}10^{-6}{\sim}2.0{\times}10^{-5}\;M$ 그리고 페닐알라닌은 $2.0{\times}10^{-6}{\sim}2.0{\times}10^{-5}\;M$이었으며, 이 구간에서 각 아미노산에 대한 상대표준편차(n = 4)는 순차적으로 3.21%, 2.64% 그리고 2.48%이었다. 그리고 각 아미노산의 검출한계($3{\sigma}/s$)는 트립토판 $6.8{\times}10^{-7}\;M$, 타이로신 $5.7{\times}10^{-7}\;M$, 페닐알라닌 $9.6{\times}10^{-7}\;M$이었다.

• Bulletin of the Korean Chemical Society
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• 제34권8호
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• pp.2256-2260
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• 2013

A new quinoline-based acylhydrazone (1) has been synthesized and applied as a fluorescent probe. Probe 1 exhibits high selectivity and sensitivity to $Cu^{2+}$ with fluorescence "ON-OFF" behavior in HEPES buffered (1‰ DMSO, HEPES 20 mM, pH = 7.4) solution. The on-site generated 1-$Cu^{2+}$ complex displays excellent selectivity to sulfide ions with fluorescence "OFF-ON" performance through copper displacement approach.

• Bulletin of the Korean Chemical Society
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• 제15권1호
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• pp.23-25
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• 1994

A simple analytical method that allows direct monitoring of small amount of CO$_2$ in a CO$_2$ discharge tube which utilizes the optoacoustic detection technique is described. The dependence of the optoacoustic signal on the mole fraction of CO$_2$ was shown that the system responded linearly to the amount of CO$_2$ present in the miniature discharge cavity equipped with Cu electrodes. It was also found that fraction of dissociated CO$_2$ varied from 14 to 37% of the initial concentration which depended on the current and the pressure in the tube. This simple and easy detection method has proven to possess the practical advantages over the conventional systems for the study of CO$_2$ laser electrodes.

• 대한핵의학회지
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• 제34권4호
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• pp.336-343
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• 2000

목적: $[^{201}Tl]$TICI주사액의 제조과정에서 안정동위원소인 $^{201}Tl$ 및 Cu, Pb의 중금속을 함유할 가능성이 있어 이러한 이물질을 확인하기 위한 방법으로 방사성 물질의 대기오염을 일으키지 않는 폴라로그래피의 분석 조건을 설정하고자 하였다. 대상 및 방법: 원자력병원에서 생산하고 있는 $[^{201}Tl]$-TlCl 주사액에 포함될 수 있는 중금속을 대상으로 하였다. 극미량의 중금속을 측정하기 위한 방법으로 BAS-50W 폴라로그래피를 이용하였고, 여기에 사용된 3 전극계는 작업전극인 DME, 기준전극인 Ag/AgCl 그리고 보조전극인 백금선을 이용하였다. 신속하고 재현성있는 분석을 위한 조건으로 기기의 분석 모드, 각 모드에 적합한 전극, 지지전해질, 석출시간 등의 치적 조건을 설정하였다. 결과: 폴라로그래피의 모드는 OSWSV 방법이 재현성과 감도면에서 가장 우수하였고, 작업전극은 DME와 Au 전극을 비교 실험한 결과 재현성 면에서 DME가 보다 좋은 결과를 보였다. 지지전해질은 염기성인 0.50 M KOH 용액, 산성인 1.0 M $HNO_3$, 용액, 중 성인 pH 7 phosphate 완충용액을 비교 실험하여 pH 7 phosphate 완충용액이 $Tl^+$과 $Cu^{2+}$를 분석하는데 가장 적합함을 확인하였다. 이를 바탕으로 중금속을 측정한 결과 $Tl^+$은 -450 mV, $Cu^{2+}$는 -50 mV에서 각각의 피크가 나타났고, 석출시간을 45초로 하였을 때 $Tl^+$의 경우 y=2.05E-$9{\chi}$+5.66E-9이고 $Cu^{2+}$의 경우는 y=1.23E-$8{\chi}$+1.23E-6의 선형 관계식을 얻었다. 결론: 이 방법에 의한 Tl과 Cu의 검출한계는 약 0.05 ppm이다. 이 방법을 현재 원자력병원에서 생산하고 있는 $[^{201}Tl]$TICl 주사액의 정도관리에 도입하여 중금속을 측정한 결과 약전에서 규정하고 있는 2 ppm 미만임을 확인하였고, 그 결과는 재현성, 정확도, 감도 및 간편성에서 모두 만족할 수 있었다. 이 방법은 $[^{201}Tl]$TlCl 주사액 뿐만 아니라 $^{67}Ga$ 주사액 및 기타 방사성의약품과 중금속 분석에도 응용할 수 있다.

• Bulletin of the Korean Chemical Society
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• 제27권9호
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• pp.1439-1444
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• 2006

A $Cu^{2+}$ ion-selective membrane microelectrode has been fabricated from poly vinyl chloride (PVC) matrix membrane containing a new symmetrical hexadentate Schiff,s base 2-{1-(E)-2-((Z)-2-{(E)-2-[(Z)-1-(2-hydroxyphenyl)ethylidene]hydrazono}-1-methylpropylidene)hydrazono]ethyl}phenol (HDNOS) as a neutral carrier, Potassium tetrakis(4-chlorophenyl) borate (KTpClPB) as an anionic excluder and o-nitrophenyloctyl ether (NPOE) as a plasticizing solvent mediator. The microelectrode displays linear potential response in the concentration range of $1.0\;{\times}\;10^{-5}-1.0\;{\times}\;10^{-11}$ M of $Cu^{2+}$. The microelectrode exhibits a nice Nernstian slope of 25.9 ${\pm}$ 0.3 mV $decade^{-1}$ in the pH range of 3.1-8.1. The sensor has a relatively short response time in whole concentration ranges ($\sim$5 s). The detection limit of proposed sensor is $5.0\;{\times}\;10^{-12}$ M (320 pg/L), and it can be used over a period of eight weeks. The practical utility of the sensor has been demonstrated by using it as an indicator electrode in the potentiometric titration of $Cu^{2+}$ with EDTA. The proposed membrane electrode was used for the direct determining of $Cu^{2+}$ content in black and red pepper, and in waste water samples.

• Bulletin of the Korean Chemical Society
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• 제26권6호
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• pp.882-886
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• 2005

Copper(II) ion-selective PVC membrane electrode based on 2-mercaptobenzoxazole as a new ionophore and o-nitrophenyl octyl ether (o-NPOE) as plasticizer is proposed. This electrode revealed good selectivity for $Cu^{2+}$ over a wide variety of other metal ions. Effects of experimental parameters such as membrane composition, nature and amount of plasticizer, and concentration of internal solution on the potential response of $Cu^{2+}$ sensor were investigated. The electrode exhibits good response for $Cu^{2+}$ in a wide linear range of 5.0 ${\times}$ 10−.6-1.6 ${\times}$ $10^{-2}$ mol/L with a slope of 29.2 ${\pm}$ 2.0 mV/decade. The response time of the sensor is less than 10 s, and the detection limit is 2.0 ${\times}$ $10^{-6}$ mol/L. The electrode response was stable in pH range of 4-6. The lifetime of the electrode was about 2 months. The electrode revealed comparatively good selectivities with respect to many alkali, alkaline earth, and transition metal ions.

• Journal of Electrochemical Science and Technology
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• 제9권3호
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• pp.169-175
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• 2018

Cu-Salen complex was prepared and attached into chitosan (Cs) polymer backbone. Nanocomposite of the synthesized polymer was prepared with functionalized carbon nano-particles (Cs-Cu-sal/C) to modify the electrode surface. The surface morphology of (Cs-Cu-sal/C) nanocomposite film showed a homogeneous distribution of carbon nanoparticles within the polymeric matrix. The cyclic voltammogram of the modified electrode exhibited a redox behavior at -0.1 V vs. Ag/AgCl (3 M KCl) in 0.1 M PB (pH 7) and showed an excellent hydrogen peroxide reduction activity. The Cs-Cu-sal/C electrode displays a linear response from $5{\times}10^{-6}$ to $5{\times}10^{-4}M$, with a correlation coefficient of 0.993 and detection limit of $0.9{\mu}M$ (at S/N = 3). The sensitivity of the electrode was found to be $0.356{\mu}A\;{\mu}M^{-1}\;cm^{-2}$.