• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.6
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• pp.666-674
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• 2019

In the mass spectrum of the mass spectrometer, the spectrum of the low peak adjacent to the spectrum having the high peak value is connected to each other and thus the separation is difficult. This inter-spectral overlap causes degradation of the mass spectral detection performance and resolution. In this paper, we propose a method to improve the mass spectrum detection performance and peak accuracy of residual gas analyzer. The type discrimination according to the characteristics of the ion signal block and the pre-correction for the peak position error can separate and detect the spectrum of the low peak connected to the adjacent spectra. To verify the performance of the proposed method, we compared the proposed method with the conventional method in simulations using actual ion signals obtained from the mass spectrometer under development.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.19 no.1
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• pp.1-19
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• 1993

Gas chromatography serves to separate the mixtures into its components, and mass spectrometer is used to analyzing of unknown compounds. But there are many problems the identification of horn compounds using by GC only. As this reason GC/MS a very powerful analyzing technique. Mass spectrometer consists of 1) inlet stem 2) ion source 3) Bass filter 4) detectors and 5) data system. There are two analyzing modes in the GC/MS, those are scan and SIM(selected ion mom toping) modes. Scan mode is used when analyzing unknown compounds and SIM mode al lows the mass spectrometer to detect specific compound with very high sensitivity. As GC/MS applications for the analysis of cosmetic products, volatile compounds in lotion, earn foundation and hair color, and carbon distribution of fatty acids in soap were performed. Also as a new sample pre-treatment technique, head space sampler/GC/MS introduced in order to analyze the volatile compounds in a toothpaste.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.63.1-63.1
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• 2011

In understanding AGN physics, it is fundamental to determine black hole masses. Based on the gas kinematics of the broad-line region, black hole masses can be derived from the product of the width of the broad emission lines and the continuum/line luminosities. For a sample of 37 intermediate-luminosity AGN at z~0.4, we obtained high quality spectra (S/N~100) using the Low Resolution Imaging Spectrometer(LRIS) at the KECK telescope, in order to calibrate various black hole mass estimators based on the Mg II (2798A), the $H{\beta}$ (4861A), and the $H{\alpha}$ (6563$\bar{A}$) emission lines. Based on our multicomponent fitting analysis, we subtract continuum, FeII emission, and host galaxy starlight, reducing systematic errors in measuring emission line widths. Combining low S/N SDSS spectra with our high S/N keck spectra, we determine a set of ~30 black hole masses of the sample for each emission line. Then by comparing various sets of black hole masses, we internally calibrate each mass estimators and investigate uncertainties and limitations of each mass estimator.

• Defense and Technology
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• no.7 s.281
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• pp.50-59
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• 2002

이 글은 독성 화학물질 테러 발생시 보다 신속하고 정확한 분석을 통해 대응능력을 향상시키고 대비태세를 더욱더 확고히 하기 위해 현재 널리 사용중인 기체분리 질량분석기(GC-MS : Gas Chromato-graph-Mass Spectrometer)와 액체분리 질량분석기의 최적의 분석기법, 미지시료 분석절차를 연구하였다. 독성 화학물질 공격에 대한 미국의 방어 대비책은 1991년 걸프전시 이라크의 화학무기 사용을 저지시키는데 일익을 담당하였다.

• Journal of the Korean Society of Tobacco Science
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• v.8 no.2
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• pp.59-66
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• 1986

The Pyrolytic behavior of glycyrrhizic acid and glycyrrhetini c acid, which are natural flavorants for manufactured cigarettes was observed to find its contribution to the smoke composition. Pyrolyzates of them at 800t were identified using a gas chromatography and a mass spectrometer. According to the analysis of the pyrolytic Products, 43 different compounds were identified Among them the aromatic hydrocarbon compounds were found to be the major products.

• Korean Journal of Pharmacognosy
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• v.44 no.4
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• pp.350-361
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• 2013

Asarum sieboldii has been used for treatment of fever, pain, common cold, and chronic sinusitis in Korea. In this study, we performed quantification analysis of seven major constituents including aristolochic acid I, aristolochic acid II, ${\alpha}$-asarone, ${\beta}$-asarone, elemicin, methyl eugenol, and safrole in the 70% ethanol extract of Asarum sieboldii and its solvent fractions, n-hexane, ethylacetate, n-butanol, and water ones using a ultra-performance liquid chromatography-electrospray ionization-mass spectrometer(UPLC-ESI-MS) and gas chromatography-mass spectrometer(GC-MS). Regression equations of seven components were acquired with $r^2$ values >0.99. The values of limit of detection(LOD) and quantification(LOQ) were 0.1-3.9 ng/mL and 0.3-11.7 mg/mL, respectively. The amount of the seven compounds in Asarum sieboldii were not detected -143.66 mg/g. The established LC-MS/MS and GC-MS methods will be helpful to improve quality control of Asarum sieboldii.

• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1386-1391
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• 1999

The methanol extract of Gardenia jasminoides Ellis showed antimicrobial activity against bacteria and yeasts. The extract was successively purified with solvent fractionation, silica gel adsorption column chromatography, Sephadex LH-20 column chromatography, octadecylsilane column chromatography. The purified active substance was isolated by high performance liquid chromatography. The isolated compound was 3,4-dihydroxybenzoic acid which was determined by mass spectrometer, gas chromatograph-mass spectrometer, $^{1}H-nuclear$ magnetic resonance, $^{13}C-nuclear$ magnetic resonance and two-dimensional nuclear magnetic resonance. The content of 3,4-dihydroxybenzoic acid was $32.7\;{\mu}g/g$ in dried fruits of Gardenia jasminoides Ellis.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.1
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• pp.120-143
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• 2018

The analytical methods and their ambient levels of organic nitrogenous compounds such as nitrosamines, nitramines (nitroamines), imines, amides and nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) in the atmosphere are summarized and discussed. Sampling for the analysis of organic nitrogenous compounds was mostly conducted using high volume air sampler. The direct liquid extraction (DLE) using sonification and the pressurized liquid extraction (PLE) using the accelerated solvent extraction (ASE) have been frequently employed for the extraction of organic nitrogenous compounds in the atmospheric samples. After extraction, clean-up via filtration and the solid phase extraction (SPE) and concentrations using nitrogen and rotary evaporator have been generally conducted but in some studies the clean-up and concentration steps have been omitted to prevent the loss of analyte and improve the recovery rate of the analytical procedure. Instrumental analysis was mainly carried out using gas chromatography (GC) or the high performance liquid chromatography (HPLC) coupled with the single quadrupole mass spectrometer or tandem mass spectrometer in the electron ionization (EI), positive chemical ionization (PCI) and negative chemical ionization (NCI) mode and analysis sensitivity of nitrosamines and nitramines were higher in NCI mode. Desirable sampling and analysis methods for analyzing particulate organic nitrogenous compounds are suggested.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.4
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• pp.263-270
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• 2020

In this study, the physical mechanism and diffusion effects in aluminium implanted silicon was investigated. For fabricating power semiconductor devices, an aluminum implantation can be used as an emitter and a long drift region in a power diode, transistor, and thyristor. Thermal treatment with O₂ gas exhibited to a remarkably deeper profile than inert gas with N₂ in the depth of junction structure. The redistribution of aluminum implanted through via thermal annealing exhibited oxidation-enhanced diffusion in comparison with inert gas atmosphere. To investigate doping distribution for implantation and diffusion experiments, spreading resistance and secondary ion mass spectrometer tools were used for the measurements. For the deep-junction structure of these experiments, aluminum implantation and diffusion exhibited a junction depth around 20 ㎛ for the fabrication of power silicon devices.

• Asian Journal of Atmospheric Environment
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• v.6 no.1
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• pp.53-66
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• 2012

A comparison of analytical approaches for Levoglucosan ($C_6H_{10}O_5$, commonly formed from the pyrolysis of carbohydrates such as cellulose) and used for a molecular marker in biomass burning is made between the four different analytical systems. 1) Spectrothermography technique as the evaluation of thermograms of carbon using Elemental Carbon & Organic Carbon Analyzer, 2) mass spectrometry technique using Gas Chromatography/mass spectrometer (GC/MS), 3) Aerosol Mass Spectrometer (AMS) for the identification of the particle size distribution and chemical composition, and 4) two dimensional Gas Chromatography with Time of Flight mass spectrometry (GC${\times}$GC-TOFMS) for defining the signature of Levoglucosan in terms of chemical analytical process. First, a Spectrothermography, which is defined as the graphical representation of the carbon, can be measured as a function of temperature during the thermal separation process and spectrothermographic analysis. GC/MS can detect mass fragment ions of Levoglucosan characterized by its base peak at m/z 60, 73 in mass fragment-grams by methylation and m/z 217, 204 by trimethylsilylderivatives (TMS-derivatives). AMS can be used to analyze the base peak at m/z 60.021, 73.029 in mass fragment-grams with a multiple-peak Gaussian curve fit algorithm. In the analysis of TMS derivatives by GC${\times}$GC-TOFMS, it can detect m/z 73 as the base ion for the identification of Levoglucosan. It can also observe m/z 217 and 204 with existence of m/z 333. Although the ratios of m/z 217 and m/z 204 to the base ion (m/z 73) in the mass spectrum of GC${\times}$GC-TOFMS lower than those of GC/MS, Levoglucosan can be separated and characterized from D (-) +Ribose in the mixture of sugar compounds. At last, the environmental significance of Levoglucosan will be discussed with respect to the health effect to offer important opportunities for clinical and potential epidemiological research for reducing incidence of cardiovascular and respiratory diseases.