• Bulletin of the Korean Chemical Society
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• 제30권10호
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• pp.2240-2244
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• 2009

A simple high performance liquid chromatographic method was developed to evaluate the quality of Moutan Cortex Radicis based on chromatographic fingerprints that characterize eight pharmacological compounds, namely, gallic acid, paeoniflorin, galloyl paeoniflorin, benzoic acid, quercetin, benzoylpaeoniflorin, paeoniflorigenone, and paeonol. These compounds were identified by their characteristic UV profiles and the mass spectroscopy data, and their contents were determined by HPLC. The chromatographic separation was performed on a $C_{18}$ column by gradient elution with 0.05% formic acid in water and acetonitrile. The methodological validation gave acceptable linearities (r = 0.9996) and recoveries (ranging from 99.4∼103.1%). The limits of detection (LOD) of these compounds ranged from 10 to 30 $\mu$g/mL. The representative chromatographic fingerprints of Moutan Cortex Radicis were obtained by analyzing 20 batches of samples collected from markets in Korea and China. For the efficient evaluation of quality for the commercial Moutan Cortex Radicis it is recommended that the total content of the six characteristic compounds should contain more than a minimum of 2% and that the content of total paeoniflorin and paeonol should exceed a minimum of 1.5% of dry weight of Moutan Cortex Radicis.

• Korean Journal of Food Science and Technology
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• 제26권5호
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• pp.512-519
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• 1994

To investigate the effects of cultivation on the aroma characteristics of essential oil of peppermint (Mentha piperita L.), experimental peppermints were cultivated with different treatments of field mulching, soil fertilization, and harvesting time. Aroma characteristics of the different mint oils were analyzed by gas chromatography (GC) and GC/mass spectrometry (MS)/infrared spectroscopy (IR). Growth of peppermint with vinyl muching was faster in the early stage of cultivation, but became almost same in the harvest date. The higher amounts of rainfall and sunshine hour resulted in the better growth of stem and leaf of the peppermint. Contents of menthone in the essential oils from the peppermint cultivated in 1990 increased as harvest date delayed from late June 25 to late July 26 the same period. In 1991 menthone decreased from June 25 to August 5, but l-menthol increased from June 25 to august 5. The results indicated that the sunshing hour affected biosynthesis of the components. Contents of menthofuran increased significantly from early June to late July. The optimum cutting date resulting best oil production was late July 7 in 1991.

• Proceedings of the Korean Vacuum Society Conference
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.577-577
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• 2013

플라즈마를 이용하는 공정은 반도체 산업에서 박막트랜지스터, 평면 모니터와 LCD 등 다양한 반도체 및 디스플레이 소자를 제작하는데 중요한 기술 중 하나로 발전되어 왔다. 현재 플라즈마 공정 기술을 이용하여 소자의 크기를 수십 나노 이하로 공정함으로써 수율을 향상시킬 수 있었지만, 소자의 미세화는 그 한계점에 봉착하였다. 그러한 이유로 웨이퍼 사이즈의 크기를 대구경화 시킴으로써 이런 문제점을 극복하고자 하였지만, 대구경 웨이퍼 사이즈에 맞는 차세대 대면적 공정 장비와 그에 따른 플라즈마 소스의 개발과 이를 컨트롤 할 수 있는 능력이 매우 절실하게 되었다. 본 연구에서는 대구경 웨이퍼용 플라즈마 소스를 위해 상대적으로 낮은 압력과 고밀도 플라즈마를 발생시킬 수 있는 유도 결합형 플라즈마원을 사용하였다. 하지만 유도 결합형 플라즈마 소스의 경우 대구경화에 따른 안테나의 길이가 길어짐으로써 생기는 정상파 효과를 피할 수가 없게 되었다. 그러한 이유로, 본 연구에서는 정상파 효과를 줄일 수 있는 상대적으로 낮은 주파수를 사용하는 안테나의 형태를 이용하여 실질적인 공정 영역에 있어서의 균일도 문제를 해결하였다. 또한, 플라즈마의 특성조절을 위해 이중주파수를 사용함 으로써 플라즈마 특성 조절을 하였다. 이러한 형태의 이중주파수를 사용하는 플라즈마 소스를 이용하여 10 mTorr의 Ar/CF4 조건에서 양이온 종들을 PSM (Plasma Sampling Mass spectroscopy, HIDEN Inc.)을 통해 에너지를 분석하였다. 이중 주파수에 있어 전력비율에 따라 IEDs (Ion Energy Distributions)는 많은 변화가 관찰되었으며, 인가하는 입력전력에 따라 E-H mode 전이가 일어남을 관찰할 수 있었다.

• Journal of the Korea Organic Resources Recycling Association
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• 제16권4호
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• pp.57-63
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• 2008

The characteristics of the bio-oil produced by the pyrolysis process with pig feces was investigated in this paper. The continuous auger-type reactor produced bio-oil was maintained at the temperature range of 400 to $600^{\circ}C$, which was higher than a typical that in a conventional pyrolysis system. The pig feces was used as the feedstock. The bio-oil and its compositions were characterized by water analysis, heating values, elemental analysis, bio-oil compounds, by Gas Chromatography/Mass Spectrometry (GC/MS), and functional group by $^1H$ NMR spectroscopy. It was found that the maximum bio-oil yields of 21% w.t. was achieved at $550^{\circ}C$. This result suggested that this auger reactor might be a potential technology for livestock waste treatment to produce bio-oil because it is able to be improved to reach higher efficiency of bio-oil production in further study. The pyrolysis system reported herein had low heat transfer into the feedstock in the auger reactor so that it needs improve the heat conduction rate of the system in further study.

• Journal of Korean Society for Atmospheric Environment
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• 제21권4호
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• pp.423-430
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• 2005

This study was investigated with sample digestion techniques and a reliability of the analytical results for a quantitative analysis of a standard reference material ('urban particulate matter', SRM 1648). The metallic elements were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) with closed vessel microwave acid digestion method and atomic absorption spectroscopy (AAS). Quality control of the overall analytical procedures for metallic element determinations of standard reference material were estimated by analysis of a SRM 1648. Three digestion solutions $(type\;1:\;HNO_3,\;type\;2:\;HNO_3\;and\;H2O_2(4'1)\;mixture,\;type\;3:5.55\%\; HNO_3\;and\;16.75\%\;HCI\;mixture)$ were applied to SRM 1648. As a result, three digestion solutions used in this study are completely unable to digest Cr of SRM 1648. Reliability of Cr and As showed some errors in the digestion with digestion solution type (3) due to the influence of chlorides. Type (3) digestion solutions are sufficient to fulfill the digestion of As as well as Se in SRM 1648. ICP-MS results showed the improvement in accurate and precise determination of some trace elements like Cd, V and Pb in SRM 1648. It is important to use the proper digestion solution for each element to qualify analytical precision.

• Journal of Microbiology and Biotechnology
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• 제26권2호
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• pp.248-254
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• 2016

A soil metagenome contains the genomes of all microbes included in a soil sample, including those that cannot be cultured. In this study, soil metagenome libraries were searched for microbial genes exhibiting lipolytic activity and those involved in potential lipid metabolism that could yield valuable products in microorganisms. One of the subclones derived from the original fosmid clone, pELP120, was selected for further analysis. A subclone spanning a 3.3 kb DNA fragment was found to encode for lipase/esterase and contained an additional partial open reading frame encoding a wax ester synthase (WES) motif. Consequently, both pELP120 and the full length of the gene potentially encoding WES were sequenced. To determine if the wes gene encoded a functioning WES protein that produced wax esters, gas chromatography-mass spectroscopy was conducted using ethyl acetate extract from an Escherichia coli strain that expressed the wes gene and was grown with hexadecanol. The ethyl acetate extract from this E. coli strain did indeed produce wax ester compounds of various carbon-chain lengths. DNA sequence analysis of the full-length gene revealed that the gene cluster may be derived from a member of Proteobacteria, whereas the clone does not contain any clear phylogenetic markers. These results suggest that the wes gene discovered in this study encodes a functional protein in E. coli and produces wax esters through a heterologous expression system.

• Journal of Microbiology and Biotechnology
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• 제28권8호
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• pp.1282-1292
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• 2018

The exopolysaccharide (EPS) produced by Bacillus amyloliquefaciens GSBa-1 was isolated and purified by ethanol precipitation, and DEAE-cellulose and Sepharose CL-6B chromatographies. The molecular mass of the purified EPS was determined to be 54 kDa. Monosaccharide analysis showed that the EPS was composed of predominantly glucose, and it was further confirmed by NMR spectroscopy to be ${\alpha}-glucan$ that consisted of a trisaccharide repeating unit with possible presence of two ${\alpha}-(1{\rightarrow}3)$ and one ${\alpha}-(1{\rightarrow}6)$ glucosidic linkages. Microstructural analysis showed that the EPS appeared as ellipsoid or globose with a smooth surface. The EPS had a degradation temperature at $240^{\circ}C$. Furthermore, the EPS had strong DPPH and hydroxyl radical scavenging activities, and moderate superoxidant anion scavenging and metal ion-chelating activities. This is the first characterization of a glucan produced by B. amyloliquefaciens with strong antioxidant activity. The results of this study suggest the potential of the EPS from B. amyloliquefaciens GSBa-1 to serve as a natural antioxidant for application in functional products.

• Korean Journal of Fisheries and Aquatic Sciences
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• 제9권3호
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• pp.203-208
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• 1976

The composition of fatty acids and sterols in the muscle lipid of eel, Anguilla japonicus Temminck & Schlegel was investigated quantitatively by using gas liquid chromatography(GLC) and the sterols separated from unsaponifiable matter by thin-layer chromatography were identified by GLC, infrared spectroscopy, nuclear magnetic resonance and GLC-mass spectrometry respectively. The fatty acids of the muscle lipid consisted of the large amount of C18:1 $(40.98\%)$, $C16:0(23.71\%)$, $C16:1(13.37\%)$ acids, and small amount of $C14:0(7.19\%),\;C18:0(5.55\%),\;C20:1(1.83\%),\;18:2(1.42\%)$ acids, and $C18:3(0.92\%),\;C15:0(0.73\%),\;C14:1(0.50\%)$ acids were smaller, Choleterol$(96.58\%)$ was a major component of the sterol fraction and 24-methylene cholesterol $(3.42\%)$ was also detected as a minor component.

• Journal of the Korean institute of surface engineering
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• 제48권6호
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• pp.322-328
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• 2015

We investigated the diffusion behaviors, electrical properties, microstructures, and composition of In-Ga-Zn-O (IGZO) oxide thin films deposited by radio frequency reactive magnetron sputtering with increasing annealing temperatures. The samples were deposited at room temperature and then annealed at 300, 400, 500, 600 and $700^{\circ}C$ in air ambient for 2 h. According to the results of time-of-flight secondary ion mass spectrometry and X-ray photoelectron spectroscopy, no diffusion of In, Ga, and Zn components were observed at 300, 400, 500, $600^{\circ}C$, but there was a diffusion at $700^{\circ}C$. However, for the sample annealed at $700^{\circ}C$, considerable diffusion occurred. Especially, the concentration of In and Ga components were similar at the IGZO thin film but were decreased near the interface between the IGZO and glass substrate, while the concentration of Zn was decreased at the IGZO thin film and some Zn were partially diffused into the glass substrate. The high-resolution transmission electron microscopy results showed that a phase change at the interface between IGZO film and glass substrate began to occur at $500^{\circ}C$ and an unidentified crystalline phase was observed at the interface between IGZO film and glass substrate due to a rapid change in composition of In, Ga and Zn at $700^{\circ}C$. The best values of electron mobility of $15.5cm^2/V{\cdot}s$ and resistivity of $0.21{\Omega}cm$ were obtained from the sample annealed at $600^{\circ}C$.

• Bulletin of the Korean Chemical Society
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• 제26권7호
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• pp.1044-1050
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• 2005

The reaction of cis-[Cr([14]-decane)($OH_2)_2]^+$ ([14]-decane = rac-5,5,7,12,12,14-hexamethyl-1,4,8,11-teraazacyclotetradecane) with auxiliary ligands {$L_a$ = isothiocyanate ($NCS^-$), azide ($N3^-$) or chloroacetate(caa)} leads to a new cis-[Cr([14]-decane)($NCS)_2]ClO_4{\cdot}H_2O$ (1), cis-[Cr([14]-decane)($N_3)_2]ClO_4$ (2) or cis-[Cr([14]-decane)($caa)_2]ClO_4$ (3). These complexes have been characterized by a combination of elemental analysis, conductivity, IR and Vis spectroscopy, mass spectrometry, and X-ray crystallography. Analysis of the crystal structure of cis-[Cr([14]-decane)($NCS)_2]ClO_4{\cdot}H_2O$ reveals that central chromium(III) has a distorted octahedral coordination environment and two $NCS^-$anions are bonded to the chromium(III) ion via the Ndonor atom in the cis positions. The angle $N_{axial}-Cr-N_{axial}$ deviates by 13$^{\circ}$ from the ideal value of 180$^{\circ}$ for a perfect octahedron. The bond angle N-Cr-N between the Cr(III) ion and the two nitrogen atoms of the isothiocyanate ligands is close to 90$^{\circ}$. The bond lengths of Cr-N between the chromium and $NCS^-$groups are 1.964(5) and 2.000(5) $\AA$. They are shorter than those between chromium and nitrogen atoms of the macrocycle. The IR spectra of 1, 2 and 3 display bands at 2073, 1344 and 1684 $cm^{-1}$ attributed to the $NCS^-$, ${N_3}^-$ and caa groups stretching vibrations, respectively.