• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.484-487
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• 2012

A discrimination technique for domestic and imported Scutellaria baicalensis was developed using an energy dispersive X-ray fluorescence spectrometer (ED-XRF). Mineral content ratios, of a total of 43 species, including P, S, Cl, K, Ca, Mn, Fe, Cu, and Zn, were measured among 204 samples. Macro element content ratios and trace element content ratios were determined using the standardless fundamental parameters (SLFP) analysis. Inorganic element ratios of P, S, K, Ca, Cl, Mn, and Fe were significantly different between domestic and imported samples. The result from the canonical discriminant analysis showed that the accuracy of geographical origin discrimination was 95.15%; the correlation coefficient was 0.888. It was concluded that this technique could be used as a useful method in discriminating the geographical origins between domestic and imported Scutellaria baicalensis.

• Economic and Environmental Geology
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• v.46 no.6
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• pp.495-508
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• 2013

Recently, stable isotopes (${\delta}^{18}O$ and ${\delta}D$) of water are increasingly analyzed using laser-based technologies. These methods have advantages over Isotope Ratio Mass Spectrometry (IRMS) in that they can be used for in-situ measurements and require much less maintenance and preparation work. Two types of laser-based methods are currently available, which have different analytical principles; OA-ICOS (off-axis integrated cavity output spectroscopy) and WS-CRDS (wavelength-scanned cavity ring-down spectroscopy). In the WS-CRDS instrument, water is vaporized at controlled environment and transferred to an optical cavity by nitrogen carrier gas, and stable isotopic compositions of water vapor are measured using the degree of absorbance of specific wavelengths and the ratios of attenuation time of the laser intensity with the sensitivity of ppb to tens of ppt level. In this study, we introduce the principle of the WS-CRDS technology and the performance results including stability and comparisons with Isotope Ratio Mass Spectrometry (IRMS) and suggest possible applications of various topics in isotope hydrology.

• Journal of the Korean Chemical Society
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• v.27 no.3
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• pp.189-193
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• 1983

The lithium isotopes separation experiments were carried out in hydrochloric acid with cation exchanger systerns. In these experiments were employed porous sulfonated styrene-divinylbenzene copolymer and Dowex 50w-x8 as cation exchanger. The contents of lithium of the fraction were determined with atomic absorption spectrophotometer. The relative mass of lithium isotopes of the fractions was analyzed on a mass spectrometer. The isotope separation factors of lithium were calculated from the isotope compositions of these eluted fractions. Separation factor for the system in hydrochloric acid and porous sulfonated styrene-divinylbenzene copolymer was found to be 1.0020, and for the case of system in hydrochloric acid and Dowex 50w-x8 was 1.0011${\om}$0.0002. From these results, we found that the separation factor for porous sulfonated styrene-divinylbenzene copolymer ionexchanger is larger than value of Dowex 50w-x8 ionexchanger.

• Economic and Environmental Geology
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• v.56 no.5
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• pp.557-564
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• 2023

Nuclear materials such as uranium are used as fuel for nuclear power generation, but there is a high possibility that they will be used for non-peaceful purposes, so international inspections and regulations are being conducted. Isotope analysis data of fine particulate obtained from nuclear facilities can provide important information on the origin and concentration method of nuclear material, so it is widely used in the field of nuclear safety and nuclear forensics. In this study we describe the analytical method that can directly identify nuclear particles and measure their isotopic ratios for fine samples using a large-geometry secondary ion mass spectrometer and introduce its preliminary results. Using the U-200 standard material, the location of fine particles was identified and the results consistent with the standard value were obtained through microbeam analysis.

• Analytical Science and Technology
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• v.11 no.4
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• pp.271-280
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• 1998

Rice flour reference materials were prepared from the unpolished rice grown in Korea and certified for elemental composition. The reference materials consist of two samples containing normal and high level. The reference material at elevated level was prepared by spiking to the normal rice flour six toxic elements of As, Cd, Cu, Cr, Hg, Pb with $1.0{\mu}g/g$ on a dry weight basis. Homogeneity of the prepared materials was evaluated through the determination of Ca, Cu, Fe, Mn, Zn by instrumental neutron activation analysis (INAA) and atomic absorption spectrometry (AAS). Small variance of elemental composition among interbottled samples assured homogeneity of the prepared materials. The materials were decomposed by high pressure digestion and microwave digestion method. INAA, AAS, inductively coupled plasma-atomic absorption spectrometry (ICP-AES), ICP-mass spectrometry (MS) and vapour generation techniques were employed to analyze the reference materials. From this independent analytical results, the certified or reference values are determined for As, Ca, Cd, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, P, Pb, Se, Zn.

• Analytical Science and Technology
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• v.23 no.5
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• pp.498-504
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• 2010

It is very difficult to get stable ion peak intensity of ruthenium by thermal ionization mass spectrometry because of its high ionization potential and high volatility of its oxides which causes to lose much of ruthenium ions, so the intensity of the signal decrease quickly. Accordingly, a study was performed in oder to increase the ionization efficiency and to prevent sample losses due to volatilization and to check with isobaric effect by impurities in filament for the measurement of ruthenium isotopes. Both single filament and double filament were tested. The former was proved to be more efficient for the stable and strong intensity of signal and revealed less isobaric effect from the molybdenum (Mo) as a filament impurity. Also, when the temperature of filament increased too high, the isobaric effect from Mo greatly appeared. That is, Mo impurity from filament gave a serious effect for measuring the ruthenium isotopes. It was proved to be of importance that filament current should be slowly increased with time interval. Finally, ruthenium isotopes were accurately measured by correction with measuring $^{94}Mo/^{99}Ru$.

• The Korean Journal of Quaternary Research
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• v.7 no.1
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• pp.41-68
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• 1993

In the loess-paleosol sequences from central Great Plains, U.S.A., variation in magnetic susceptibility, FD, NRM have been proven to be excellent proxy for paleoclimate, and the standard interpretation is that climatic processes have enhanced the rock magnetic intensities. By using mineral magnetic properties, we show the magnetic signal is due to pedogenesis during the warm and possibly wet interglacials and interstadials. Other proxy records, such as stable carbon isotope and phytolith, are in good agreements with the magnetic records.

• Analytical Science and Technology
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• v.23 no.6
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• pp.518-523
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• 2010

In this paper, the study of analysis of uranium isotopes in environmental samples with a kinetic phosphorescence analyzer (KPA) was described. After leaching uranium fraction from soil and glass material with microwave acid digestion technology, uranium isotopes were purified with UTEVA column, and then measured using KPA. Linearity and repeatability tests for measurement of uranium isotopes were carried out in the uranium standard solution with KPA. The reliability for analytical method of uranium with KPA was validated by its application to uranium standard solution, ground water, IAEA and NIST reference samples.

• Journal of Conservation Science
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• v.9 no.1
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• pp.11-20
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• 2000

The body composition of an ancient roofing tiles excavated from Chonnam province has been investigated by X-ray diffraction, and inductively coupled plasma spectroscopy. Ancient roofing tiles were excavated at ancient mountain fortress and kiln sites. The body composition of roofing tiles was different according to the excavated sites. The mineral component of roofing tiles were grouped in the five types and chemical composition was different according to the excavated areas. It is presumed that the body of roofing tiles used low-grade raw materials containing $Fe_2O_3$ 4-10%. The trace element composition of the roofing tiles were different, and it might be all ret1ection of different geological characteristics. The characteristic element of rooting tiles was vanadium element of the analyzed 20 trace elements. By $SiO_2-V$ distribution diagram types, roofing tiles excavated from the Geomdan mountain fortress at Sunchon, kiln site in Yeochon, Gorak and Cheoksan mountain fortress at Yeosu were grouped into the same excavated site.

• Korean Journal of Heritage: History & Science
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• v.49 no.4
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• pp.38-51
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• 2016

This study reports on human dietary reconstruction of Joseon Dynasty using stable isotope analysis. The stable carbon and nitrogen isotope values were measured of bone collagen extracted from 25 human bones from archaeological site in Myeongam-ri, Asan. Average values of ${\delta}^{13}C$ and ${\delta}^{15}N$ are $-19.7{\pm}0.5$‰(n=23) and $9.6{\pm}1.1$‰(n=23), respectively. The isotopic data indicates that Myeongam-ri individuals consumed $C_3$ plants mainly and assumed of dietary resourced from a terrestrial animal protein. Previous isotopic studies of the Joseon era suggested that dietary composition of Joseon population was not influenced by region and burial type. Also comparison of the isotopic results of male and female from double burials showed sex-dependent dietary patterns among individuals living in the same circumstances.