Calibration, uncertainty, and recovery in the chromatographic sciences

Vanatta, L.E.; Coleman, David E.

doi:10.1016/j.chroma.2007.02.040

Cited by 32 publications

(15 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…8 Excel spreadsheets were developed to calculate the measurement uncertainty by these two methodologies, based on GUM approach.…”

Section: Methodsmentioning

confidence: 99%

Internal standard versus external standard calibration: an uncertainty case study of a liquid chromatography analysis

Oliveira¹,

Müller²,

Abad³

et al. 2010

Quím. Nova

View full text Add to dashboard Cite

, 8.000, 94930-000 Cachoeirinha -RS, BrasilRecebido em 22/9/09; aceito em 30/11/09, publicado na web em 8/4/10Traditionally, in the cigarettes industry, the determination of ammonium ion in the mainstream smoke is performed by ion chromatography. This work studies this determination and compares the results of this technique with the use of external and internal standard calibration. A reference cigarette sample presented measurement uncertainty of 2.0 mg/cigarette and 1.5 mg/cigarette, with external and internal standard, respectively. It is observed that the greatest source of uncertainty is the bias correction factor and that it is even more significant when using external standard, confirming thus the importance of internal standardization for this correction.

show abstract

“…8 Excel spreadsheets were developed to calculate the measurement uncertainty by these two methodologies, based on GUM approach.…”

Section: Methodsmentioning

confidence: 99%

Internal standard versus external standard calibration: an uncertainty case study of a liquid chromatography analysis

Oliveira¹,

Müller²,

Abad³

et al. 2010

Quím. Nova

View full text Add to dashboard Cite

show abstract

“…15,16 As fontes de incerteza que não são cobertas pela recuperação são obtidas nos testes de robustez.…”

unclassified

Comparação de diferentes abordagens para avaliação da incerteza na cromatografia gasosa do gás natural

Oliveira

Aguiar

2009

Quím. Nova

View full text Add to dashboard Cite

Recebido em 8/10/08; aceito em 12/2/09; publicado na web em 3/7/09 COMPARISON OF DIFFERENT APPROACHES TO EVALUATE THE UNCERTAINTY OF GAS CHROMATOGRAPHY FOR NATURAL GAS. The evaluation of uncertainty associated with an analytic result is an essential part of the measurement process. Recently, several approaches to evaluate the uncertainty in measurement have been developed. Here, the gas chromatography assay uncertainty for natural gas is compared by some of these approaches: the guide to the expression of uncertainty in measurement (GUM) approach, top-down approach (reproducibility estimate from an inter-laboratory study), Barwick & Ellison (data from validation), study of variability and fuzzy approach. The comparison shows that GUM, Barwick & Ellison and fuzzy approaches lead to comparable uncertainty evaluations, which does not happen with the top-down approach and study of variability by the absence of data normality.Keywords: measurement uncertainty; GUM approach; top-down approach. INTRODUÇÃOA incerteza de uma medição é definida como "um parâmetro, associado ao resultado de uma medição, que caracteriza a dispersão dos valores que podem ser fundamentalmente atribuídos a um mensurando".1 O resultado de uma medição é considerado como a melhor estimativa do valor do mensurando acompanhado de todas as fontes da incerteza que contribuem à propagação do mesmo.2,3 Consequentemente, um resultado de medição não pode corretamente ser interpretado sem conhecimento sobre a incerteza deste resultado. 2Vários conceitos foram desenvolvidos para a avaliação de incerteza relacionada a um resultado de medição. Uma das primeiras abordagens para avaliar a incerteza em Química Analítica foi publicada nos anos 80. Wernimont usou estimativas de precisão a partir de estudos interlaboratoriais em desempenho de métodos para avaliar a incerteza.4 Outra abordagem para a expressão da incerteza de medição é proposta pelo GUM.3 Esta abordagem combina as diversas fontes de incerteza, através da expansão da série de Taylor. No início dos anos 1990, o EURACHEM adotou o GUM como referência de uso em Química Analítica.5 Entretanto, como o número de situações no dia a dia do laboratório não é trivial, a identificação e quantificação de todas as fontes de incerteza fizeram com que os químicos analíticos relutassem em adotar esta abordagem. Em contra partida, o Comitê de Métodos Analíticos (AMC) da Sociedade Real de Química retomou a proposta de Wernimont, introduzindo a abordagem top-down baseada em estudos interlaboratoriais.2 Logo após, o Comitê Nórdico para Análises de Alimentos (NMKL) sugeriu uma abordagem similar, baseada somente em dados provenientes de estudos intralaboratoriais. 6 Os dados necessários para a abordagem topdown, ou ao menos uma parte deles, já estão geralmente disponíveis na validação do método.A discussão na avaliação da incerteza de medição influenciou também o ISO/IEC 17025 e os laboratórios que requisitam a acreditação.7 A seção desta norma sobre incerteza cita que "a estimativa razoável deve estar baseada no conheci...

show abstract

“…Therefore, it is important to choose the correct calibration model for each particular analyte even though this could prove to be time consuming, particularly when establishing a new method for over a hundred analysts [2], [3]. The unwise choice of a calibration model may give rise to inaccuracies as high as 100% for analytical determinations due to the presence of high random errors and bias [9]. Statistical calculations and distributions therefore, play a major role in performing validation in chemical measurements and analytical determinations as well as systematically determining the level of certainty reached by the analytical procedure [9].…”

Section: Introductionmentioning

confidence: 99%

“…The unwise choice of a calibration model may give rise to inaccuracies as high as 100% for analytical determinations due to the presence of high random errors and bias [9]. Statistical calculations and distributions therefore, play a major role in performing validation in chemical measurements and analytical determinations as well as systematically determining the level of certainty reached by the analytical procedure [9].…”

Section: Introductionmentioning

confidence: 99%

“…One of the important things that should consider during analysis is the calibration and that any calibration expression is adequate, important statistics-related questions must be asked. It should be noted that although all of the following questions are important, perhaps the most important (and often neglected) query is the last one regarding uncertainty [9]. 1) Was the design of the calibration study appropriate?…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Quality Control Assessment for Chemical Analysis

2016

IJSR

View full text Add to dashboard Cite

Abstract:The current research focused on the importance of quality control for chemical analysis through instrument calibration conditions, on different organochlorine pesticides samples using standard mixture solutions. For this aim statistical quality control calculations were performed to optimize the validation of Gas chromatography mass spectrometry (GC-MS) and its compatibility range. The obtained quality control assessment results confirmed instrument method's performance in term of the instrument accuracy, excellent sensitivity and selectivity of the consequences.

show abstract

Calibration, uncertainty, and recovery in the chromatographic sciences

Cited by 32 publications

References 2 publications

Internal standard versus external standard calibration: an uncertainty case study of a liquid chromatography analysis

Internal standard versus external standard calibration: an uncertainty case study of a liquid chromatography analysis

Comparação de diferentes abordagens para avaliação da incerteza na cromatografia gasosa do gás natural

Quality Control Assessment for Chemical Analysis

Contact Info

Product

Resources

About