• 대한화학회지
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• 제42권2호
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• pp.197-202
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• 1998

1-(2-Pyridylazo)-2-Naphthol (PAN)은 많은 금속이온들과 착색된 착물을 형성함으로 분광시약 또는 금속지시약으로 널리 사용된다. 본 연구는 PAN을 이동상에 첨가하여 Cu(II), Ni(II) , Zn(II), Co(II) , 및 Fe(III)이온들과 착물을 형성시켜 역상 액체크로마토그래피법으로 분리하였다. 이들 금속착물들은 570nm에서 분광광도 검출기로 검출되었고, 이들 금속이온의 머무름을 조사하기 위하여 이동상의 pH, 이온세기 및 유기용매 조성의 변화에 따른 크로마토그램과 용량인자를 측정하였다. 이상의 실험결과에서 얻은 최적조건하에서 금속이온을 분리한 결과 좋은 크로마토그램을 얻었으며, 검출한계(S/N)도 ppb단위까지 검출이 가능함을 알 수 있었다.

• 분석과학
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• 제30권3호
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• pp.154-158
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• 2017

The Korean Pharmacopoeia (KP XI), British Pharmacopoeia (BP 2013) and Japanese Pharmacopoeia contain monographs for the quality control of raw fusidate sodium and its formulations using high performance liquid chromatography (HPLC). However, the assay method for the determination of fusidate sodium in commercial tablets is titration which is less specific than HPLC. In this study, we present an alternative HPLC method for quantitation of fusidate sodium in tablets. Method validation was performed to determine linearity, precision, accuracy, system suitability, and robustness. The linearity of calibration curves in the desired concentration range was high ($r^2=0.9999$), while the RSDs for intra- and inter-day precision were 0.25-0.37 % and 0.11-0.60 %, respectively. Accuracies ranged from 99.46-100.85 %. Since the system suitability, intermediate-precision and robustness of the assay were satisfactory, this method will be a valuable addition to the Korean Pharmacopoeia (KP XI).

• 대한유전성대사질환학회지
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• 제17권2호
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• pp.39-47
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• 2017

Purpose: A sensitive gas chromatography mass spectrometry (GC-MS) method was developed for screening of fatty acid oxidation disorders. Methods: The assay utilized a simple protein precipitation with sulfosalicylic acid followed by tert-butyl dimethylsilyl (TBDMS) derivatization of hydroxyl functional group by N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide (MTBSTFA). Results: Calibration curves of spiked pooled plasma showed a linear relationship in the range of 0.01 ng -2 mg with correlation coefficient value greater than 0.98. Limits of detection (LOD) and limits of quantification (LOQ) were found in the range of 0.9-8.8 ng and 9-88 ng, respectively. Conclusion: The new developed method might be useful for a rapid, sensitive screening of inherited fatty acid oxidation disorders. In addition, the method expected to be one of the alternative method for screening newborns of metabolic disorders in the laboratories where expensive MS/MS is unavailable.

• 대한기계학회논문집B
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• 제30권2호
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• pp.153-160
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• 2006

A technique for measuring surface temperature field in micro scale is newly proposed, which uses temperature-sensitive fluorescent (TSF) dye coated on the surface and is easily implemented with a fluorescence microscope and a CCD camera. The TSF dye is chosen among mixtures of various chemical compositions including rhodamine B as the fluorescent dye to be most sensitive to temperature change. In order to examine the effectiveness of this temperature measurement technique, numerical analysis and experiment on transient conduction heat transfer for two different substrate materials, i. e., silicon and glass, are performed. In the experiment, to accurately measure the temperature with high resolution temperature calibration curves were obtained with very fine spatial units. The experimental results agree qualitatively well with the numerical data in the silicon and glass substrate cases so that the present temperature measurement method proves to be quite reliable. In addition, it is noteworthy that the glass substrate is more appropriate to be used as thermally-insulating locally-heating heater in micro thermal devices. This fact is identified in the temperature measuring experiment on the locally-heating heaters made on the wafer of silicon and glass substrates. Accordingly, this technique is capable of accurate and non-intrusive high-resolution measurement of temperature field in microscale.

• 한국환경과학회지
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• 제13권2호
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• pp.175-180
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• 2004

A prompt gamma-ray neutron activation (PGNA) system was simulated by the Monte Carlo N-Particle transport code (MCNP-4A) to estimate the level at which the scattered photon fluence rate, the absolute efficiency of the HPGe-detector, the volume of the concrete sample and the $^{35}$ /Cl(n, ${\gamma}$) reaction rate in this sample contribute to the count rate in the NaCl concentration measurement. The n- ${\gamma}$ fluence rates at the ST-2 beam tube exit of the HANARO reactor were used as input data, and the GAMMA-X type HPGe detector was modeled to tally 1.1649 MeV ${\gamma}$ -rays emitted from the $^{35}$ Cl(n, ${\gamma}$) reaction in the concrete sample. For three cylindrical concrete samples of 13.8, 46.8 and 157.1 ㎤ volumes, respectively, the relations between the NaCl weight fractions of 0.1, 1, 2 and 5 % in each of the concrete samples and the 1.1 649 MeV pulses created in the HPGe detector model were studied. As a result, it was found that the count rate at the same NaCl concentration nearly depends on the volume of the samples in a simulated condition of the same NaCl concentration samples, and that the linearities of the NaCl concentration calibration curves were reasonable in the narrow range of the NaCl weight fraction.

• 분석과학
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• 제12권2호
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• pp.94-98
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• 1999

Quadrupole Mass Spectrometer를 이용하여 핵연료봉으로부터 포집된 1기업이하 소량의 기체들로부터 그들의 조성과 동위원소비를 구하는 방법을 검토하였다. He, $N_2$, $O_2$, Ar, Kr, Xe의 개별기체와 혼합기체를 이용하여 기체압력과 조성비에 따른 검정곡선의 직선성을 조사하였다. Sample chamber와 analyser chamber 사이에 부착된 molecular leak의 영향을 조사하였으며, 시료와 유사한 조성을 갖는 혼합표준기체로부터 각 기체의 감도를 얻은 후 동일조건에서 시료를 분석하였다. 측정압력 범위에서 Kr과 Xe의 동위원소간 감도차는 크게 나타나지 않았다.

• Toxicological Research
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• 제29권3호
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• pp.203-209
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• 2013

A simple and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantification of ${\varepsilon}$-acetamidocaproic acid (AACA), the primary metabolite of zinc acexamate (ZAC), in rat plasma by using normetanephrine as an internal standard. Sample preparation involved protein precipitation using methanol. Separation was achieved on a Gemini-NX $C_{18}$ column ($150mm{\times}2.0mm$, i.d., 3 ${\mu}m$ particle size) using a mixture of 0.1% formic acid-water : acetonitrile (80 : 20, v/v) as the mobile phase at a flow rate of 200 ${\mu}l/min$. Quantification was performed on a triple quadrupole mass spectrometer employing electrospray ionization and operating in multiple reaction monitoring (MRM) and positive ion mode. The total chromatographic run time was 4.0 min, and the calibration curves of AACA were linear over the concentration range of 20~5000 ng/ml in rat plasma. The coefficient of variation and relative error at four QC levels were ranged from 1.0% to 5.8% and from -8.4% to 6.6%, respectively. The present method was successfully applied for estimating the pharmacokinetic parameters of AACA following intravenous or oral administration of ZAC to rats.

• 소성∙가공
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• 제19권8호
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• pp.494-501
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• 2010

The main objective of this study is to examine the sensitivity of calibration curves of FEA of ring compression test to frictional shear factor. Ring compression test has been investigated by measuring dimensional changes at different positions of ring specimen and they include the changes in internal diameter at the middle and top section of the specimen, outer diameter at the middle and top section, surface expansion at the top surface, respectively. Initial ring geometries employed in analysis maintain a fixed ratio of 6 : 3 : 2, i.e. outer diameter : inner diameter : thickness of the ring specimen, which is generally known as 'standard' specimen. A rigid plastic material for different work-hardening characteristics has been modeled for simulations using rigid-plastic finite element code. Analyses have been performed within a definite range of friction as well as over whole range of friction to show different sensitivities to the interfacial friction for different ranges of friction. The results of investigation in this study have been summarized in terms of a dimensionless gradient. It has been known from the results that the dimensional changes at different positions of ring specimen show different linearity and sensitivity to the frictional condition on the contact surface.

• Carbon letters
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• 제11권3호
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• pp.206-210
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• 2010

Removal of dyes Reactive Blue 221, N Blue RGB and Acid Blue MTR using two different samples of activated carbon by static batch method was studied. Experimental data on optical density of solutions at different concentrations ranging from 10 to 100 mg/L and of solutions after adsorption on activated carbon samples were measured. Calibration curves were plotted and the amount of dye $q_e$ adsorbed was calculated. The data was fitted to Langmuir and Freundlich isotherms for two different carbon samples and different concentration and pH values. Constants were calculated from the slope and intercept values of the isotherms. Coefficient of correlation $R_2$ and Standard Deviation SD were also noted. The data fitted well to the isotherms. Carbon sample $C_1$ showed higher potential to adsorb all the three dyes. Adsorption was higher at lower concentrations. Carbon sample $C_2$ showed better adsorption in acidic pH as compared to in alkaline pH. From the analysis of the data capacity of $C_1$ and $C_2$ to remove the dyes from water have been compared.

• 대한한의학회지
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• 제31권6호
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• pp.8-15
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• 2010

Objectives: We investigated to develop and validate HPLC-PDA methods for simultaneous determination of eight constituents in Galgeun-tang (GGT). Methods: Reverse-phase chromatography using a Gemini C18 column operating at $40^{\circ}C$, and photodiode array (PDA) detection at 230 nm, 254 nm, and 280 nm, were used for quantification of the eight marker components of GGT. The mobile phase using a gradient flow consisted of two solvent systems. Solvent A was 1.0% (v/v) aqueous acetic acid and solvent B was acetonitrile with 1.0% (v/v) acetic acid. Results: Calibration curves were acquired with $r^2$ > 0.9999, and the relative standard deviation (RSD) values (%) for intra- and inter-day precision were less than 3.0%. The recovery rate of each component was in the range of 87.33-101.38%, with an RSD less than 7.0%. The contents of the eight components in GGT were 1.98-12.17 mg/g. Conclusions: The established method will be applied for the quantification of marker components in GGT.