Uncertainties related to linear calibration curves: a case study for flame atomic absorption spectrometry

Detalhes bibliográficos
Autor(a) principal: Chui,Queenie S. H.
Data de Publicação: 2007
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Journal of the Brazilian Chemical Society (Online)
Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532007000200027
Resumo: Least squares linear regression is widely used in analytical chemistry. In practice a linear relationship between substance content and measured value still has been assumed based on the correlation coefficient criterion, although not recommended. Textbooks provide the necessary formulas for the fitting process, based on the assumption that there is no error in the independent variable. In practice the ordinary least squares (OLS) textbook procedure is used even when the previously stated assumptions are not strictly fulfilled. In this paper, how to validate the calibration function is dealt with in detail using as an example based on measurements obtained for nickel determination by flame atomic absorption spectrometry (FAAS). Assessing uncertainties related to linear calibration curves is also discussed. Considering uncertainties of weights and volumetric equipment and instrumental analytical signal it is observed that the most important factor that contributes to the final uncertainty is the uncertainty of the calibration function.
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spelling Uncertainties related to linear calibration curves: a case study for flame atomic absorption spectrometrymetrologyuncertaintycalibration functionflame atomic absorption spectrometryLeast squares linear regression is widely used in analytical chemistry. In practice a linear relationship between substance content and measured value still has been assumed based on the correlation coefficient criterion, although not recommended. Textbooks provide the necessary formulas for the fitting process, based on the assumption that there is no error in the independent variable. In practice the ordinary least squares (OLS) textbook procedure is used even when the previously stated assumptions are not strictly fulfilled. In this paper, how to validate the calibration function is dealt with in detail using as an example based on measurements obtained for nickel determination by flame atomic absorption spectrometry (FAAS). Assessing uncertainties related to linear calibration curves is also discussed. Considering uncertainties of weights and volumetric equipment and instrumental analytical signal it is observed that the most important factor that contributes to the final uncertainty is the uncertainty of the calibration function.Sociedade Brasileira de Química2007-04-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532007000200027Journal of the Brazilian Chemical Society v.18 n.2 2007reponame:Journal of the Brazilian Chemical Society (Online)instname:Sociedade Brasileira de Química (SBQ)instacron:SBQ10.1590/S0103-50532007000200027info:eu-repo/semantics/openAccessChui,Queenie S. H.eng2007-06-13T00:00:00Zoai:scielo:S0103-50532007000200027Revistahttp://jbcs.sbq.org.brONGhttps://old.scielo.br/oai/scielo-oai.php||office@jbcs.sbq.org.br1678-47900103-5053opendoar:2007-06-13T00:00Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ)false
dc.title.none.fl_str_mv Uncertainties related to linear calibration curves: a case study for flame atomic absorption spectrometry
title Uncertainties related to linear calibration curves: a case study for flame atomic absorption spectrometry
spellingShingle Uncertainties related to linear calibration curves: a case study for flame atomic absorption spectrometry
Chui,Queenie S. H.
metrology
uncertainty
calibration function
flame atomic absorption spectrometry
title_short Uncertainties related to linear calibration curves: a case study for flame atomic absorption spectrometry
title_full Uncertainties related to linear calibration curves: a case study for flame atomic absorption spectrometry
title_fullStr Uncertainties related to linear calibration curves: a case study for flame atomic absorption spectrometry
title_full_unstemmed Uncertainties related to linear calibration curves: a case study for flame atomic absorption spectrometry
title_sort Uncertainties related to linear calibration curves: a case study for flame atomic absorption spectrometry
author Chui,Queenie S. H.
author_facet Chui,Queenie S. H.
author_role author
dc.contributor.author.fl_str_mv Chui,Queenie S. H.
dc.subject.por.fl_str_mv metrology
uncertainty
calibration function
flame atomic absorption spectrometry
topic metrology
uncertainty
calibration function
flame atomic absorption spectrometry
description Least squares linear regression is widely used in analytical chemistry. In practice a linear relationship between substance content and measured value still has been assumed based on the correlation coefficient criterion, although not recommended. Textbooks provide the necessary formulas for the fitting process, based on the assumption that there is no error in the independent variable. In practice the ordinary least squares (OLS) textbook procedure is used even when the previously stated assumptions are not strictly fulfilled. In this paper, how to validate the calibration function is dealt with in detail using as an example based on measurements obtained for nickel determination by flame atomic absorption spectrometry (FAAS). Assessing uncertainties related to linear calibration curves is also discussed. Considering uncertainties of weights and volumetric equipment and instrumental analytical signal it is observed that the most important factor that contributes to the final uncertainty is the uncertainty of the calibration function.
publishDate 2007
dc.date.none.fl_str_mv 2007-04-01
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dc.identifier.uri.fl_str_mv http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532007000200027
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dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv 10.1590/S0103-50532007000200027
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dc.format.none.fl_str_mv text/html
dc.publisher.none.fl_str_mv Sociedade Brasileira de Química
publisher.none.fl_str_mv Sociedade Brasileira de Química
dc.source.none.fl_str_mv Journal of the Brazilian Chemical Society v.18 n.2 2007
reponame:Journal of the Brazilian Chemical Society (Online)
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reponame_str Journal of the Brazilian Chemical Society (Online)
collection Journal of the Brazilian Chemical Society (Online)
repository.name.fl_str_mv Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ)
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