• 한국진공학회:학술대회논문집
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• 한국진공학회 2002년도 제23회 학술발표회 초록집
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• pp.136-136
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• 2002

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1659-1662
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• 2003

The mass measurement of solid density standards using weight exchanger is described. KRISS(Korea Research Institute od Standards and Science) has several solid density standards. Their mass have been measured manually only using a mass comparator(Mettler, 1kg - 0.01mg). However, the uncertaity of the manual mass measurement is up to 300 microgarm much more than 32 microgram of advanced NMIS(National Metrology Institutes) for 1 kg silicon sphere which is primary density standards due to an eccentric error and buoyancy correction error. The new system with a weight exchanger is designed and built to improve the measurement accuracy. It comprises a weight exchager, a mass comparator, air density instruments, and application program for automatic measurement. It is evaluated by measuring several elements in an air tight chamber to verify the performance of it.

• Mass Spectrometry Letters
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• 제9권4호
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• pp.105-109
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• 2018

A certified reference material (CRM) for the analysis of inorganic nutrients in nutritional supplements has been developed. Accurate mass fractions of chromium (Cr), iron (Fe), copper (Cu), and zinc (Zn) were determined by isotope dilution inductively coupled plasma mass spectrometry (ID ICP/MS). The measurement results were used to assign certified values for the CRM, which were metrologically traceable to the definitions of the measurement units in the International System of Units (SI). Production of a candidate reference material (RM) and the certification processes are summarized. Each nutrient in the CRM showed good homogeneity, which was estimated using relative standard deviations of the measurement results of twelve bottles in a batch. This CRM is expected to be an important reference to improve reliability and comparability of nutrient analyses in nutritional supplements and related samples in analytical laboratories.

• 한국진공학회지
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• 제16권2호
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• pp.91-98
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• 2007

한국표준과학연구원 진공기술센터에서 잔류기체분석기 교정장치를 개발하였으며, 이 장치를 이용하여 서로 다른 구조를 가진 두개의 사중극 질량분석기 (quadrupole mass spectrometer)의 질소, 아르곤, 헬륨에 대한 기체감도를 측정하였다. 그 결과 기체감도는 QMS 구조와 상관없이 기체의 질량이 클수록 높게 나타났고 압력에 따라서도 다른 특성을 보였으므로 정확한 사용을 위해서는 기체감도를 꼭 보정해야 함을 알 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제10권6호
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• pp.524-529
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• 1989

A glow discharge mass spectrometric(GDMS) analytical method was developed for direct analysis of impurities in solids. Ions extracted from a glow discharge ion source with a sample as a cathode were analyzed by a quadrupole mass filter. Ion extractions were carried out through differentially-pumped orifices biased to positive and negative potentials. Operating parameters of the glow discharge source such as discharge current, orifice-to-cathode distance, energy analyzer setting and bias voltages have been optimized. The developed GDMS was applied to the analysis of KSS copper-base alloy standards certified by Korea Standards Research Institute(KSRI). In the analysis, the reproducibility and the detection limits were estimated to be about 2.5% RSD, and in the low ppm range, respectively.

• Bulletin of the Korean Chemical Society
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• 제29권11호
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• pp.2125-2128
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• 2008

• Mass Spectrometry Letters
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• 제11권4호
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• pp.108-112
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• 2020

A certified reference material (CRM) for the analysis of nutrient elements in an edible mushroom (Ganoderma lyceum) powder has been developed (KRISS CRM 108-10-011). The mass fractions of calcium (Ca), iron (Fe), and zinc (Zn) were measured by isotope dilution inductively coupled plasma mass spectrometry (ID ICP/MS). To dissolve the fungi cell wall of mushroom consisted of chitin fibers, sample preparation method by single reaction chamber type microwave-assisted acid digestion with acid mixtures was optimized. The mean measurement results obtained from 12 sample bottles were used to assign as the certified values for the CRM and the between-bottle homogeneities were evaluated from the relative standard deviations. The certified values were metrologically traceable to the definition of the kilogram in the International System of Units (SI). This CRM is expected to be used for validation of analytical methods or quality control of measurement results in analytical laboratories when they determine the mass fractions of elements in mushroom or other similar samples.

• Mass Spectrometry Letters
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• 제3권1호
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• pp.18-20
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• 2012

We report observation of laser desorption/ionization (LDI) of peptides from flat surfaces of tungsten silicide ($WSi_2$). In contrast to MALDI (matrix-assisted laser desorption/ionization) and SALDI (surface-assisted laser desorption/ionization) mass spectrometry, this study did not utilize any matrices and surface nanostructures. In this work, LDI on $WSi_2$ surfaces is demonstrated to cover a mass range up to 1,600 Da (somatostatin; monoisotopic mass = 1637.9 Da). In addition, it exhibited a high sensitivity, which could detect peptides, which could detect peptides of low femtomole levels (20 fmol for angiotensin II). The observed LDI process was discussed to be largely thermal, more specifically, due to laser-induced surface heating that is most likely promoted by the low thermal diffusivity (${\kappa}$) of $WSi_2$ substrate.

• 비파괴검사학회지
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• 제28권2호
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• pp.151-156
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• 2008

반도체나 디스플레이 제조 등 진공공정의 리크검출에는 질량분석기형(mass spectrometer type) 헬륨 리크검출기(leak detector)가 사용되고 있다. 이 기기를 이용해서 안정된 측정값을 얻기 위해서는 장치 내부에 내장된 투과형(permeation type) 표준리크(standard leak)를 이용해서 자주 spectrometer를 교정해야 한다. 본 연구에서 질량분석기형 리크검출기의 비교교정 장치의 개발과 교정방법에 대한 연구결과를 언급하였다. 따라서 이 기술을 이용하면 질량분석기형 리크검출기를 구비하고 있는 현장에서도 표준리크의 비교교정이 가능하게 된다.

• Mass Spectrometry Letters
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• 제4권4호
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• pp.75-78
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• 2013

A gas chromatography/mass spectrometric (GC/MS) method was developed as a candidate reference method for the accurate determination of essential fatty acids (linoleic acid, ${\alpha}$- and ${\gamma}$-linolenic acids) in food supplemental oil products. Samples were spiked with three internal standards (stearic acid-$d_{35}$, $^{13}C_{18}$-linoleic acid, and $^{13}C_{18}$-${\alpha}$-linolenic acid). Samples were then subject to saponification, derivatization for methylation, and extraction by organic solvent. For GC/MS measurement, an Agilent HP-88 column, designed for the separation of fatty acid methyl esters, was selected after comparing with other columns as it provided better separation for target analytes. Target analytes and internal standards were detected by selected ion monitoring of molecular ions of their methyl ester forms. The GC/MS method was applied for the measurement of three botanical oils in NIST SRM 3274 (borage oil, evening primrose oil, and flax oil), and measurement results agreed with the certified values. Measurement results for target analytes which have corresponding isotope-labeled analogues as internal standard were calculated based on isotope dilution mass spectrometry (IDMS) approach, and compared with results calculated by using the other two internal standards. Results from the IDMS approach and the typical internal standard approach were in good agreement within their measurement uncertainties. It proves that the developed GC/MS method can provide similar metrological quality with IDMS methods for the measurement of fatty acids in natural oil samples if a proper fatty acid is used as an internal standard.