• Title/Summary/Keyword: species unspecific isotope dilution

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Study of improving precision and accuracy by using an internal standard in post column isotope dilution method for HPLC-ICP/MS (후 컬럼 동위원소 희석법을 적용한 HPLC-ICP/MS에서의 정량분석에서 내부 표준물을 이용한 정확도와 정밀도의 개선연구)

  • Joo, Mingyu;Park, Myungsun;Pak, Yong-Nam
    • Analytical Science and Technology
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    • v.27 no.3
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    • pp.140-146
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    • 2014
  • An internal standard was used in PCID (post column isotope dilution) to improve the accuracy and precision in quantification of various chemical species. The error occurring in the column was the largest in HPLC-ICP/MS (high performance liquid chromatography-inductively coupled plasma/mass spectrometry) when PCID and other traditional quantification methods were compared with each other. Internal standard was effective in correcting the loss of sample in the column to improve accuracy and precision. When applied to SeMet, using MeSecys or $Se^{4+}$ as an internal standard, relative errors were reduced from 31% and 13% to less than 1%, while standard deviations were reduced from 5.1% and 6.9% to 1.5% and 0.2%, respectively. Positive aspects of using an internal standard in PCID were compared with other quantitative techniques and discussed in detail.

A short study of uncertainty for post column isotope dilution method in HPLC-ICP/MS (HPLC-ICP/MS에서 후 컬럼 동위원소 희석법의 기초적인 불확도 연구)

  • Joo, Mingyu;Pak, Yong-Nam
    • Analytical Science and Technology
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    • v.27 no.6
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    • pp.269-276
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    • 2014
  • A short study for the uncertainty of post column isotope dilution method has been performed for the analysis of Selenomethionine in HPLC-ICP/MS. Major error sources studied were concentration and the flow rate of Se isotope solution, atomic weights of Se in spike and sample, and isotope ratio measured for the spiked sample. Uncertainties were obtained for each factor and the contribution for the total concentration uncertainty was 54.4% and 0.61%, 0.0072% and 0.018%, and 45.0%, respectively. The biggest contribution factor was concentration of the spike solution and the second was the isotopic ratio measured for the spiked sample solution. The mass flow rate of spike and atomic weights did not show much contribution. The calculated total uncertainty was $1.46ng{\cdot}g^{-1}$ for the standard SeMet ($126.30ng{\cdot}g^{-1}$). The experimental result was $127.09{\pm}1.46ng{\cdot}g^{-1}$ and the relative uncertainty was 1.20%.