• Bulletin of the Korean Chemical Society
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• 제29권2호
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• pp.352-356
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• 2008

An analytical method has been developed for measuring chlorostyrenes in fish tissue sample. Extraction of chlorostyrenes from fish tissue was carried out by ultrasonication using acetone/n-hexane (5:2, v/v) mixture. Most of the lipids in the extract were eliminated by freezing-lipid filtration, prior to solid-phase extraction (SPE) cleanup. During freezing-lipid filtration, about 90% of the lipids extracted from the fish samples were easily removed without any significant losses of chlorostyrenes. For purification, SPE using Florisil was used for the rapid and effective cleanup. Quantification was performed using gas chromatography-mass spectrometry in the selected ion monitoring mode. Spiking experiments were carried out to determine the recovery, precision, and limits of detection (LODs) of the method. The overall recovery was above 80% in the spiked fish tissue sample at 10 and 100 ng/g levels, respectively. The detection limits for chlorostyrenes were ranged from 0.05 to 0.1 ng/g. This developed method is demonstrated to give efficient recoveries and LODs for detecting chlorostyrenes spiked into fish tissue with high lipid content.

• 대한방사성의약품학회지
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• 제2권2호
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• pp.84-95
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• 2016

Considerably increasing interest in using the theranostic isotopes/ isotope pairs of radiometals like $^{44/47}Sc$ and $^{64/67}Cu$ for diagnosis and/or therapeutic applications in the nuclear medicine procedures necessitates its reliable production and supply. Separation and purification of no-carrier-added (NCA) isotopes from macro quantitates of the irradiated target matrix along with other impurities is a cardinal procedure amongst several other steps involved in its production. Multitudinous methods including but not limited to liquid-liquid (solvent) extraction, extraction chromatography (EXC), ion exchange, electrodeposition and sublimation are routinely applied either solitarily or in combination for the separation and purification of radioisotopes depending on their production routes, radioisotope of interest and impurities involved. However, application of EXC though has shown promises towards the numerous separation techniques have not received much attention as far as its application prospects in the field of nuclear medicine are concerned. Advances in the recent past for application of the EXC resins in separation and purification of the several medically important radioisotopes at ultra-high purity have shown promising behavior with respect to their operation simplicity, acidic and radiolytic stability, separation efficiencies and speedy procedures with the enhanced and excellent extraction abilities. In this mini review we will be talking about the recent developments in the application and the use of EXC techniques for the separation and purification of $^{44/47}Sc$ and $^{64/67}Cu$ for medical applications. Furthermore, we will also discuss the scientific and practical aspects of EXC in the view of separation of the NCA trace amount of radionuclides.

• 분석과학
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• 제6권1호
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• pp.131-139
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• 1993

아연광 중 미량으로 존재하는 갈륨 및 인듐을 유도결합 플라스마 원자방출분광법(ICP-AES)으로 분석할 때 간섭하는 아연 및 다른 이온들과 특히 Fe(III) 이온으로부터 이들을 분리하는 방법에 대해 연구하였다. 갈륨과 인듐을 tributyl phosphate(TBP)로 용매추출하였는데 이때 영향을 주는 산농도, 다른 이온들의 간섭, 수용액상/유기상의 비율, TBP의 농도 및 탈거율 등에 대하여 조사하였다. 갈륨과 인듐이 함유되어 있는 아연광을 녹인 5N 염산용액에서 100% TBP로 추출하여 아연 및 기타 간섭이온들로부터 분리하였으며, 이때 철(III)이온은 hydroxylamine hydrochloride를 사용하여 Fe(II)로 환원시켜 coetraction되는 것을 방지하였다. 유기상으로부터 갈륨과 인듐의 탈거는 0.02N 염산용액으로 역추출하여 이루어졌으며 이 용액을 ICP-AES로 측정하여 이들을 정량하였다. 전체적으로 추출률이 95% 이상으로 정량적이었다.

• Bulletin of the Korean Chemical Society
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• 제29권7호
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• pp.1327-1331
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• 2008

Novel $CO_2$-soluble 8-hydroxyquinoline (8-HQ) chelating agents were synthesized and evaluated for solubility and metal ion extraction ability in supercritical $CO_2\;(Sc-CO_2)$. Among them, secondary amide-containing 8- HQ derivatives cannot be dispersed well into Sc-$CO_2$, but tertiary amide-containing derivatives can dissolve completely in Sc-$CO_2$ even at low CO2 pressures, perhaps owing to the predominant intermolecular interaction between the chelating agent and the $CO_2$ molecule. Based on 8-HQ chelating agent solubility data, we investigated the extraction of metal ions ($Co^{2+}$, $Cu^{2+}$, $Sr^{2+}$, $Cd^{2+}$, and $Zn^{2+}$) using two highly $CO_2$-soluble 8-HQ derivatives (4d, 4e) in Sc-$CO_2$. The extraction efficiency of tertiary amide-containing 8-HQ ligands, both fluorinated and non-fluorinated forms, was dramatically increased in the presence of diethyl amine (organic base). We suggest that diethyl amine could play an important synergistic role in the stronger metal binding ability of 8-HQ through an in situ deprotonation reaction in Sc-$CO_2$ medium.

• 자원리싸이클링
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• 제12권1호
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• pp.25-32
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• 2003

도금폐수로부터 철, 구리, 아연 및 니켈 등 중금속을 분리ㆍ회수하기 위한 용매추출시 추출제의 종류 및 평형 pH에 따른 각 금속의 분리효과를 조사하였다. 실험결과 아연은 추출제로 PC-88A가 가장 효과적이며, pH 2.5에서 100% 추출할 수 있다. 구리와 니켈은 LIX 84를 사용하여 추출하면 각각 pH2에서 100% 그리고 pH4～5에서 90% 이상 추출할 수 있다. 한편, 중금속이 혼재한산ㆍ알칼리계 도금폐수에 대한 용매추출에서는 먼저 3가 철을 지방산인 20％의 Naphthenic acid나 10％의 Versatic acid-10로 pH2∼2.5 부근에서 분리ㆍ회수하고, 그 다음에 3%의 LIX 84를 사용하여 pH2에서 구리를 용매추출하여 분리하고 난 후 20% PC-88A 로 pH2.5∼3에서 아연을 용매추출하여 회수하면 수상에 니켈만이 잔류하여 각각의 금속분리가 가능하다.

• 한국식품영양과학회지
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• 제22권4호
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• pp.500-509
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• 1993

Pectins present in the primary cell walls and middle lamellae of plant cell walls are extracted by water, cheating agents, acid or alkali solutions. However, some neutral contaminating components are extracted in conjunction with pectins during the extraction process. Thus, the accurate characterization of physi-cochemical properties of pectins necessitates to get rid of the impurities. In this review, dialysis, alcohol precipitation, ion exchange chromatography and metal precipitation were compared as procedures to purify the pectin extracts. In addition, the chemical methods to analyze pectins are discussed in terms of three major chemical constituents, i.e., anhydrogalacturonic acid, methoxyl groups and neutral sugars.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전기물성,응용부문
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• pp.204-206
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• 2003

Electron beam generator of cold cathode type has been developed for industrial application, for example, waste water cleaning, flue gas cleaning, and pasteurization etc. The operational principle is based on the emission of secondary electrons from cold cathode when ions in the plasma hit the cathode, which are accelerated toward exit window by the gradient of an electric potential. The characteristics of secondary electron emission are studied by comparing total cathode current with ion current.

• Bulletin of the Korean Chemical Society
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• 제31권11호
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• pp.3395-3398
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• 2010

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2005년도 춘계학술발표회
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• pp.175-176
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• 2005

• 약학회지
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• 제8권4호
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• pp.96-99
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• 1964

In the previous study, the composition ratios of the Cu-sulfa drugs complexes determined by gravimetric and solvent extraction method reported. In this paper, the continuous variations method has been used to know whether the complexes are simple complexes or chelates, and to recertify the composition ratios of the complexes at pH 7-8. It has been certified that the ratio of $Cu^{+2}$ ion to sulfa drugs in 1:2 from the result of this experiment.