• 한국세라믹학회지
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• 제47권6호
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• pp.485-490
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• 2010

In our previous studies, continuous SiC fiber-reinforced SiC-matrix composites ($SiC_f$/SiC) had been fabricated by two different slurry infiltration methods: vacuum infiltration and electrophoretic deposition (EPD). 12 wt% of $Al_2O_3-Y_2O_3$-MgO with respect to SiC powder was used as additives for liquid-phase assisted sintering. After hot pressing at $1750^{\circ}C$ under 20 MPa for 2 h in Ar atmosphere, a high composite density could be achieved for both cases, whereas the problems such as large grain size and non-uniform distribution of liquid phase were observed, which was resulted in the relatively poor mechanical properties of composites. Therefore, efforts have been made to reduce the grain growth during the sintering, including the optimization for hot pressing condition and utilization of spark plasma sintering using a SiC monolith. Based on the results, spark plasma sintering was found to be effective method in decreasing the amount of sintering additive, time and grain growth, which will be explained in comparison to the results of hot pressing in this paper.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.395.3-396
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• 2002

A simple, rapid and reliable high performance liquid chromatography (HPLC) method has been developed for the measurement of lansoprazole in human plasma, and the application of pharmacokinetic study has been evaluated. Omeprazole was used as an internal standard. After adding methyl tert-butyl ether, samples were stored at －7$0^{\circ}C$. The extracts were easily obtained only with pouring the organic phase. The mobile phase was prepared using acetonitrile and water at the volume ratio of 38:62. (omitted)

• 마이크로전자및패키징학회지
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• 제12권3호
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• pp.235-241
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• 2005

Incorporation of solid electrodes frequently involves plasma-based processing. The effect of plasma can influence the physical characteristics, depending on the magnitude in plasma. The undesired feature of plasma-induced damage should be prevented in characterizing the ultra-thin materials, such as ultra-thin films and organic monolayers. The current work at first proves the applicability of a liquid phase electrode in the electrical/dielectric properties through comparative work using Al and Hg on ultrathin $Al_2O_3$ films deposited through atomic layer deposition at low temperature: Two types of metals such as Aluminum (Al) and mercury (Hg) were used as electrodes in $Al_2O_3$ thin films in order to investigate the effect of electrode preparation on the current-voltage characteristics and impedance features as a function of thickness in $Al_2O_3$ film thickness. The success of Hg in $Al_2O_3$ thin films is applied to the AC and DC characterization of the organic monolayers obtained using the Langmuir-Blodgett method. From the DC current-voltage characteristics, the diode-like response is found to originate from the bulk response of the organic materials, evidenced by the fact and the capacitance is inversely related to the absolute thickness of organic layers.

• Archives of Pharmacal Research
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• 제22권1호
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• pp.86-88
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• 1999

An advance d and sensitive high-performance liquid chromatographic (HPLC) method for determination of omeparzole in human plasma has been developed. After omeprazole was extracted from plasma with diethylether, the organic phase was transferred to another tube and trapped back with 0.1 N NaOH solution. The alkaline aqueous layer was injected into a reversed-phase C8 column. Lansoprazole was used as an internal standard. The mobile phase consisted of 30% of acetonitrile and 70% of 0.2 M $ KH_{2}PO_{4}$, pH 7.0. Recoveries of the analytes and internal standard were >75.48%. The coefficients of variation of intra- and inter-day assay were <5.78 and 4.59% for plasma samples. The detection limit in plasma was 2 ng/ml. The clinical applicability of this assay method was evaluated by determining plasma concentration-time courses of the respective analytes in 24 healthy volunteers after oral administration 40 mg of omeprazole. The present assay is considered to be simple, accurate, economical and suitable for the study of the kinetic disposition of omeprazole in the body.

• 분석과학
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• 제19권3호
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• pp.239-243
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• 2006

본 연구는 LLE(liquid-liquid extraction) 전처리 방법과 HPLC/UV를 이용하여 혈장에서 이트라코나졸을 정량 분석하는 방법을 연구하였다. 이트라코나졸과 내부표준물질(펠로디핀)을 디에틸에테르로 추출하고 C18 컬럼을 이용하여 분리한 후 UV 검출기를 통하여 254 nm에서 검출하였다. 이동상은 10 mM 아세트산 암모늄 완충액(pH 7) :아세토나이트릴(35:65, v/v) 혼합용액을 사용하였으며, 유속은 0.2 mL/min.으로 하였다. 정량범위는 2~1,000 ng/mL 이며, 상관관계($R^2$)는 0.9991로 좋은 직선성을 보였다. 정량한계는 2 ng/mL, 재현성은 변동계수가 10.8 이하, 정확도는 97.2~108.2% 였다. 이 분석방법은 혈장 중의 약물 정량 및 약물의 약동력학에 유용함을 보여주었다.

• Korean Chemical Engineering Research
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• 제49권3호
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• pp.271-276
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• 2011

대면적 대기압 플라즈마 반응 장비를 플라즈마-용액 시스템에 적용하여 액상 내부에 잠입된 폴리프로필렌(PP) 필름의 표면손상 없이 관능기 도입 가능성을 탐색하였다. 액상으로 1-butyl-3-methylimidazolium tetrafluoroborate: $[BMIM]^{+}[BF_{4}]^{-}$ 이온성 액체 수용액을 사용한 경우, 안정적으로 플라즈마를 발생시킬 수 있었다. PP 필름의 플라즈마 처리 결과, PP 표면에 다양한 산소 함유 관능기들이 도입되었음을 확인할 수 있었다. 플라즈마 처리 후 PP의 표면 자유에너지는 처리시간, 전압의 증가에 따라서 증가하며, 1.5M 이온성 액체 수용액 농도에서 가장 큰 값을 나타내었다. ATR-FTIR 분석 결과, 다양한 카르보닐 기(1,726 $cm^{-1}$, 1,643 $cm^{-1}$)와 하이드록시 기$(3,100{\sim}3,500\;cm^{-1})$의 흡광도가 증가하였고, XPS 분석은 ATR-FTIR 분석 결과를 뒷받침하여 주었다.

• 한국임상약학회지
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• 제10권1호
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• pp.38-41
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• 2000

A high-performance liquid chromatographic method with fluorometric detection was evaluated for analysis of ofloxacin in plasma. Biological fluids (plasma, $200\;{\mu}L$) were prepared for assay by protein precipitation with chlorofurm. The detection of ofloxacin and triamterene as an internal standard were performed at 358 nm for excitation and 495 nm for emission. The HPLC separation was carried out on Ultrasphere ODS column (4.6 mm${\times}25\;cm,\;5\;{\mu} m$) with acetonitrile $(45\%)$-phosphoric acid $(1.5\%)\;containing\;0.3\%$ sodium laurylsulfate as the mobile phase. The flow-rate was 1.0 mL/min. The calibration graphs were linear from 3.0 to 80 ng/mL with r=0.998. The minimal detectable concentration in plasma was 1.5 ng/mL. The proposed technique is reproducible, selective, reliable and sensitive.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.220.1-220.1
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• 2003

A sensitive and selective liquid chromatographic method for the determination of carvedilol in human plasma was developed and validated. Analytes were separated on a XTerra C18 column with acetonitrile-methanol-30 mM KH$_2$PO$_4$ (pH 2.5) (20 : 20 : 60, v/v/v), as mobile phase. One mL plasma were pipetted into glass tubes and spiked with 0.05 mL of internal standard solution. After adding 7 mL of diethyl ether, the plasma sample was then shacked for 15 min. A centrifuged upper layer was back-extracted with 150 uL of 0.05 M sulfuric acid. (omitted)

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.401.3-402
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• 2002

Enalapril (ENP) maleate is effective drug for the treatment of renivascular hypertension and heart failure. ENP acts as inhibitor of the enzyme angiotensin-convertase (ACE-inhibitor) and metabolized to enalaprilat (ENPT), which is the active metabolite that is really responsible for the therapeutic action. In the present study, a sensitive and rapid liquid chromatography/ electrospray ion trap tandem mass spectrometry (LC/MS/MS) method combined with high-throughput solid phase extraction (SPE) has been developed and validated for the simultaneous quantitative determination of ENP and ENPT in human plasma. (omitted)

• 대한수의학회지
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• 제28권2호
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• pp.321-325
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• 1988

This experiment was carried out to determine the progesterone concentration of bovine plasma by liquid phase double antibody enzyme immunoassay. The optimum conditions of assay-system, double (first and second) antibody and carrier (normal rabbit serum) were investigated. The optimum dilution rate of first antibody, second antibody and normal rabbit serum was $10{\times}10^3$ to $15{\times}10^3$, 20 and $1{\times}10^3$ times, respectively.