• Bulletin of the Korean Chemical Society
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• 제22권5호
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• pp.503-506
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• 2001

Separation of lithium isotopes was investigated by chemical ion exchange with a hydrous manganese(IV) oxide ion exchanger using an elution chromatography. The capacity of manganese(IV) oxide ion exchanger was 0.5 meq/g. One molar CH3COO Na solution was used as an eluent. The heavier isotope of lithium was enriched in the solution phase, while the lighter isotope was enriched in the ion exchanger phase. The separation factor was calculated according to the method of Glueckauf from the elution curve and isotopic assays. The single stage separation factor of lithium isotope pair fractionation was 1.021.

• Bulletin of the Korean Chemical Society
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• 제29권7호
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• pp.1295-1296
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• 2008

• 한국광과학회:학술대회논문집
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• 한국광과학회 1996년도 학술대회지
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• pp.32-32
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• 1996

• Bulletin of the Korean Chemical Society
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• 제19권11호
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• pp.1249-1252
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• 1998

• 대한화학회지
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• 제30권3호
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• pp.312-319
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• 1986

알킬 처리된 실리카(ODS)칼럼을 정지상으로하여 역상에서의 이온-쌍 크로마토그래피 법으로 방향족 카르복시산들의 크기 인자를 조사하고 분리하는데 반대 이온으로 브롬화 도데실트리메틸암모늄(DTAB)을 사용하였다. 시료의 크기 인자는 반대 이온의 농도, 메탄올의 농도, 전해질의 종류 및 농도, 시료 분자에 붙어 있는 다른 작용기의 종류 및 위치등에 따라 영향을 받았다. 최적 조건하에서 몇 가지 혼합 시료를 분리할 수 있었다.

• 공업화학
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• 제3권1호
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• pp.100-110
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• 1992

수용액에서 amlne류와 arylsulfonyl carbamate류를 반응시켜 다음과 같은 arylsulfonyl urea유도체들을 좋은 수율로 쉽게 합성할 수 있다 : 1) N-Arylsulfonyl-N'-arylurea 유도체, 2) N-Arylsulfonyl-N'-alkyl urea 유도체, 3) N-Arylsulfonyl-N'-heterocyclic urea 유도체. Arylsulfonyl urea의 합성에 관한 반응메카니즘은, 먼저 산-염기 반응에 의해 ion-pair형태가 만들어지고, 그 다음 사면체형 중간체를 형성하는 친핵성첨가반응, 그리고 산촉매에 의한 alkoxide ion과 양성자의 제거반응에 따라 일어난다.

• Archives of Pharmacal Research
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• 제19권5호
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• pp.396-399
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• 1996

High-performance liquid chromatographic method with UV detecction was developed for the determination of theophylline and its metabolites in human urine using ${beta}$-hydroxyethyl theophylline$({beta} -HET)$ as an internal standard. For extraction of urine sample, quality control sample and xanthine-free blank urine were mixed with decylamine (ion-paring reagent) and ${beta}$-HET. After saturation with ammonium sulfate, the mixture was then extracted with organic solvent at pH values of 4.0-4.5. All separations were performed with ion-pair chromatography using decylamine as an ion-pairing reagent and 3mM sodium acetate buffered mobile phase (pH 4.0) containing 1% (v/v) acetonitrile and 0.75 mM decylamine. The detection limits of theophylline, 1, 3-DMU, 1-MU, 3-MX and 1-MX in human urine were 0.17, 0.17, 0.39, 0.19 and 0.19 ${\mu}g$/ml, based on a signal-to-noise ratios of 3.0. The mean intraday coefficients of variation (C.V.s) of each compound on nine replicates were lower than 2.0%, while mean interday C.V.s on three days were lower than 1.6%. All separations were finished within 40miutes.

• 분석과학
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• 제12권3호
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• pp.203-208
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• 1999

살리실산 및 그 유도체들의 이온쌍 고성능 액체크로마토그래피 용리거동을 이동상 중 이온쌍 시약(tetrabutylammonium chloride, TBACl)의 농도를 변화시키면서 용량인자, k'를 측정함으로서 고찰하였다. 이동상의 pH 및 TBACl의 농도가 증가함에 따라 시료들의 k'는 증가하였다. 살리실산 정량의 최적 이동상 조건은 pH 7.2에서 20 mM TBACl을 함유한 메탄올 용액($MeOH:H_2O$ 30:70), p-아미노살리실산(PAS)은 40 mM TBACl을 함유한 메탄올 용액($MeOH:H_2O$ 20:80) 이었다. 머무름 거동의 관찰로부터 발견한 최적 조건에서 몇 가지 유도체들을 분리하였으며 아울러 아스피린과 결핵 치료제 중 살리실산 유도체들의 함량을 조사하였다.

• Journal of Magnetics
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• 제20권4호
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• pp.366-370
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• 2015

New ion beam etcher (IBE) using a magnetized inductively coupled plasma (M-ICP) has been developed. The magnetic flux density distributions inside the upper chamber, where the plasma is generated by inductive coupling, were successfully optimized by arranging a pair of circular coils very carefully. More importantly, the proposed M-ICP IBE exhibits higher etch rate than ICP.

• Archives of Pharmacal Research
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• 제9권2호
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• pp.111-114
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• 1986

Bretylium tosylate is a quaternary ammonium compound used for the treatment of ventricular fibrilation in humans. It is advantageous to other cationic compound in the study of biliary excretion in that negligible amount is bound to plasma protein and metabolite is not likely is to be formed. Some researchers reported that the formation of ion-pair complex caused to increase the lipothilicity of cationic compound. The partition of bretylium between water and organic phase was increased with the addition of sodium taurodeoxycholate. Also sensitive gas chromatographical assay procedure using flame ionization detector was studied. This procedure can detect as low as 0.1 mg/ml using 0.1 ml biological sample, but contamination by previous injection is the major problem of this method.