• Title/Summary/Keyword: Impurities

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Determination of Trace Impurities in Gold by Isotope Dilution Inductively Coupled Plasma Mass Spectrometry

  • Lee, Gae-Ho;Yang, Suk-Ran;Park, Chang-Jun;Lee, Kwang-Woo
    • Bulletin of the Korean Chemical Society
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    • v.14 no.6
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    • pp.696-700
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    • 1993

  • Gold bonding wire of 0.076 mm in diameter used in semiconductor industry, is dissoved in aqua regia. The solution is then evaporated to near dryness several times with a few drops of HCl added to prepare the final sample solution in 5% HCl. The gold matrix is separated from trace impurities by controlled potential deposition. The whole electrolysis has been carried out inside a clean bench. An optimum potential is found to be +0.25 V to give more than 99.9% Au matrix removal with better than 90 analytes remaining in the electrolyte solution. Isotope dilution calibration is employed to get the best accuracy and precision. Analytical results are presented with determination limits of the analytical method.

  • https://doi.org/10.5012/bkcs.1993.14.6.696 인용 PDF

Direct Anlysis of Impurities in Solides with Glow Discharge Mass Spectrometry

  • Ki Beom Lee;Dae Won Moon;Kwang Woo Lee
    • Bulletin of the Korean Chemical Society
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    • v.10 no.6
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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.

  • https://doi.org/10.5012/bkcs.1989.10.6.524 인용 PDF

A study on the effect of material impurity concentration on radioactive waste levels for plans for decommissioning of nuclear power plant

  • Gilyong Cha;Minhye Lee;Soonyoung Kim;Minchul Kim;Hyunmin Kim
    • Nuclear Engineering and Technology
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    • v.55 no.7
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    • pp.2489-2497
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    • 2023

  • Co and Eu impurities in the SSCs are nuclides that dominantly influence the neutron-induced radioactive inventory in metal and concrete radwastes (radioactive wastes) during NPP decommission. The impurity concentrations provided by NUREG/CR-3474 were used for the practical range of Co and Eu impurity concentrations to be applied to the code calculations. Metal structures near the core were evaluated to be ILW (intermediate-level waste) for the whole range of Co impurity concentration, so the boundary line between ILW and LLW (low-level waste) has no change for the whole concentration range provided by NUREG/CR-3474. Also, the boundary line between VLLW (very low-level waste) and CW (clearance waste) in the concrete shield could alter a little depending on the Eu impurity concentration within the range provided by NUREG/CR-3474. From this work, it is found that the concentration of material impurities of SSCs gives no critical impact on determining radwaste levels.

  • https://doi.org/10.1016/j.net.2023.04.001 인용 PDF