• Title, Summary, Keyword: Mass spectrometer

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Characteristics of Quadrupole Mass Spectrometer for Partial Pressure Measurement in CO-$H_2$ Gas Mixture (CO와 $H_2$ 혼합기체에 대한 Quadrupole Mass Spectrometer의 감도 특성)

  • 신용현;홍승수;정광화
    • Journal of the Korean Vacuum Society
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    • v.2 no.3
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    • pp.314-318
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    • 1993
  • Quadrupole mass spectrometer는 부분압 측정 및 잔류기체 분석에 널리 이용되고 있는 장비이다. CO, H2, Ar이 혼합되어 존재할 때 quadrupole mass spectrometer의 감도를 10-4∼10-8torr영역에서 측정하고 단일기체로 존재할 때의 감도와 비교하였다. 그 결과 일정한 부분압을 유지하고 있는 경우라도, 주위 분위기 기체 종류와 부위기 기체 압력에 따라 감도 별화가 심한 것을 알 수 있었다. 따라서 QMS를 부분압 측정이나 조성분석에 이용하기 위해서는 이에 대한 특성조사가 반드시 필요하다.

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Membrane Inlet-based Portable Time-of-flight Mass Spectrometer for Analysis of Air Samples

  • Kim, Tae-Kyu;Jung, Kyung-Hoon;Yoo, Seung-Kyo;Jung, Kwang-Woo
    • Bulletin of the Korean Chemical Society
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    • v.26 no.2
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    • pp.303-308
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    • 2005
  • A miniaturized time-of-flight mass spectrometer with an electron impact ionization source and sheet membrane introduction has been developed. The advantages and features of this mass spectrometer include high sensitivity, simple structure, low cost, compact volume with field portability, and ease of operation. A mass resolution of 400 at m/z 78 has been obtained with a 25 cm flight path length. Under optimized conditions, the detection limits for the volatile organic compounds (VOCs) studied were 0.2-10 ppm by volume with linear dynamic ranges greater than three orders of magnitude. The response times for various VOCs using a silicone membrane of 127 $\mu$m thickness were in the range 4.5-20 s, which provides a sample analysis time of less than 1 minute. These results indicate that the membrane introduction/time-of-flight mass spectrometer will be useful for a wide range of field applications, particularly for environmental monitoring.

Structural Determination of Cerebrosides from Soybean Embryo by Mass Spectrometer (Mass Spectrometer를 이용한 대두 배아 출추 Cerebroside의 구조 분석)

  • Kim, Jung-Hun;Chang, Sug-Youn;Kim, Yeo-Kyung
    • Analytical Science and Technology
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    • v.6 no.3
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    • pp.335-343
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    • 1993
  • The structure of cerebrosides from soybean embryo was determined using fast atom bombardment mass spectrometer (FAB-MS), gas chromatography mass spectrometer (GC-MS) and TLC. The components of cerebroside were determined by GC-MS after acid hydrolysis. The molecular weight distribution of cerebroside was measured by positive mode FAB-MS with LiOH saturated 3-nitrobenzylalcohol(3-NBA) matrix. Structures of individual components of complex mixtures can be determined easily by this process. The major constituent of soybean extracted cerebroside was determined as the glucoside of N-2'-hydroxypalmitoyl-sphingadienine.

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Application of Computer-coupled Mass Spectrometer for Continuous On-line Monitoring of Cell Growth and Growth Rate (세포증식과 증식속도의 On-line Monitoring을 위한 Computer- coupled Mass Spectrometer의 응용)

  • 남수완;최춘순;김정회
    • Microbiology and Biotechnology Letters
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    • v.17 no.3
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    • pp.241-246
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    • 1989
  • Continuous on-line monitoring of cell concentration and growth rate in aerobic batch fermentation process was carried out by analyzing the exhaust gas composition of tormentor with a quadrupole mass spectrometer. From the mass spectrometric analyses of major gaseous components, i.e. $N_2$, $O_2$, $CO_2$ and $H_2O$, and the material balance equations for oxygen and carbon dioxide, oxygen uptake rate (OUR) rind carbon dioxide evolution rate (CER) were instantaneously calculated using a computer (16-bit IBM PC-AT) interfaced to a quadrupole mass spectrometer. The calculated OUR and CER data were used for the estimation of cell concentration and growth rate of Candida utilis during batch culture. It was found that the cell concentration could be satisfactorily estimated from the data of OUR arid CER during the culture and this method could be successfully und for the continuous monitoring of cell growth and growth rate.

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Development of Comparative Calibration System for Helium Leak Standard by Using Mass Spectrometer Type Leak Detector (질량분석기형 누출검출기를 이용한 헬륨투과형 표준 누출 비교 교정 장치 개발)

  • Hong, Seung-Soo;Lim, In-Tae;Kim, Jin-Tae;Shin, Yong-Hyeon
    • Journal of the Korean Society for Nondestructive Testing
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    • v.28 no.2
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    • pp.151-156
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    • 2008
  • Many kinds of mass spectrometer type leak detectors have been widely used for detecting leak of vacuum processes in semiconductor and display industries etc. The leak detectors should be often calibrated by the permeation type standard leak in order to ensure accurate and reproducible leak measurement. We have developed a comparative calibration system for permeation type standard leak by using mass spectrometer type leak detector and specification of the calibration method. Following this technique the reliable calibration for leak standard ran be performed even in fields.

Hot Electron Emission Test of an Ion Source for a Micro Mass Spectrometer (초소형 질량 분석기를 위한 이온 발생기의 열전자 방출 시험)

  • Yoon, Hyeun-Joong;Kim, Jung-Hoon;Park, Tae-Gyu;Yang, Sang-Sik;Jung, Kwang-Woo
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.50 no.8
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    • pp.419-422
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    • 2001
  • This paper presents the principle and fabrication of a novel micro mass spectrometer and emission test of hot electron for ionization. A micro mass spectrometer consists of a micro ion source and a micro ion separator. The micro ion source consists of a hot filament and grid electrodes. Electrons emitted from a hot filament are to ionize some sample molecules. The ions are accelerated to an ion detector by an electric field. Mass can be analyzed by using the time of fight depending on the mass-to-charge ratio. The current of hot electron emission from the hot filament is measured for various input voltages.

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Analysis of contaminated QMS, cleaning and restoration of functions (오염된 QMS의 원인 분석과 세정 및 기능 복원)

  • Kim, Donghoon;Joo, Junghoon
    • Journal of the Korean institute of surface engineering
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    • v.48 no.4
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    • pp.179-184
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    • 2015
  • Quadrupole Mass Spectrometers (QMS) is a very useful tool in vacuum process diagnosis. Tungsten filament based ion sources are vulnerable to contamination from process gas monitoring. Common symptoms of quadrupole mass spectrometer malfunction is appearance of unwanted contaminant mass peaks or no detection of any ion peaks. We disassembled used quadrupole mass spectrometer and found out black insulating deposits on inside of ion source parts. Five steps of cleaning procedure were applied and almost full restoration of functions were confirmed in two types of closed ion source quadrupole mass spectrometer. By using a numerical modeling (CFD-ACE+) technique, the electric potential profile of ion source with/without insulating deposit was calculated and showed the possibility of quadrupole mass spectrometer malfunction by the deterioration of designed potential profile inside the ion source.

Application of Mass Spectrometer-based Electronic Nose for Discrimination of Angelicae gigantis radix

  • Noh, Bong-Soo;Youn, Aye-Ree;Lee, Nam-Yun
    • Food Science and Biotechnology
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    • v.14 no.4
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    • pp.537-539
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    • 2005
  • Potential of mass spectrometer-based electronic nose to discriminate habitat of Angelicae gigantis radix was evaluated using 24 and 86 Korean and non-Korean samples, respectively. Loading plot(s) of principal component analysis of data measured through this system revealed difference between Korean samples (probability; 100%) and non-Korean ones (probability; 95.3%), suggesting this technique could be used as efficient method to differentiate habitat of A. gigantis radix.

Calibration of Quadrupole Mass Spectrometer for Various Gases (Quadrupole Mass Spectrometer의 기체별 감도 특성)

  • 신용현;홍승수;이철로;임재영;박재홍;정광화
    • Journal of the Korean Vacuum Society
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    • v.2 no.1
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    • pp.9-16
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    • 1993
  • 부분압 분석 장비의 감도 측정 시스템을 설계 제작하였다. 이 시스템을 이용하여 부분압측정기기로 많이 쓰이는 Quadrupole Mass Spectrometer의 N2, O2, Ar, CO, H2에 대한 감도를 10-4∼10-8torr 영역에서 측정하여 감도의 압력 의존성을 보고 검출 방식, Emission current, Secondary Electron Multiplier 전압 등이 감도에 미치는 영향도 측정하였다. 실험 결과 기체 종류에 따라서는 물론 사용조건에 따라서도 감도의 절대값 변화 및 압력 의존성 변화가 아주 심한 것을 알 수 있었다. 따라서 Quadrupole Mass Spectrometer를 정량적인 측정에 이용하기 위해서는 이에 대한 감도 측정 및 특정조사가 반드시 선행되어야 한다.

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Simultaneous Determiniation of Ar/$N_2$Ratios in Groundwater (지하수에 용해된 질소, 아르곤 가스의 동시측정)

  • Kim, Euisik;Roy F. Spalding
    • Journal of the Korean Society of Groundwater Environment
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    • v.1 no.1
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    • pp.6-9
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    • 1994
  • Previously reported Ar/N$_2$ratios in groundwater have been measured by single ion monitoring (Barnes et al., 1975; Vogel et al., 1981; Mariotti et al., 1988). The detector geometry and flared flight tube in VG Optima isotopic ratio mass spectrometer appeared to be fortuitously aligned for the simultaneous measurement of Ar/N$_2$ratios. Method development included mechanical adjustments to optimize the mass spectrometer for Ar/N$_2$ratio measurements followed by development of a preparation system for the extraction of air-saturated water samples. Samples containing known Ar/N$_2$ratios were used to assess accuracy and precision, and to test the applicability of methods for measurements of aqueous Ar/N$_2$ratios. The results indicated that the prepared air-saturated water samples were almost identical to the predicted Ar/N$_2$ratios (p <0.001). Groundwater samples were collected from on-going research sites, Shelton and Grand Island, Nebraska. Samples from the Grand Island sludge injection site form a lower boundary for worldwide reported Ar/N$_2$ratios. These lower Ar/N$_2$ratios can be explained by the production of nitrogen gas from this site, where denitrification was reported previously.

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