References of "Rudaz, S"
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See detailChapter 3 Method Transfer Between Conventional HPLC and UHPLC
Debrus, Benjamin ULg; Rozet, Eric ULg; Hubert, Philippe ULg et al

in Guillarme, Davy; Veuthey, jean-Luc (Eds.) UHPLC in Life Sciences (2012)

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See detailEvaluating the reliability of analytical results using a probability criterion: a Bayesian perspective
Rozet, Eric ULg; Govaerts, B.; Lebrun, Pierre ULg et al

in Analytica Chimica Acta (2011), 705

Methods validation is mandatory in order to assess the fitness of purpose of the developed analytical method. Of core importance at the end of the validation is the evaluation of the reliability of the ... [more ▼]

Methods validation is mandatory in order to assess the fitness of purpose of the developed analytical method. Of core importance at the end of the validation is the evaluation of the reliability of the individual results that will be generated during the routine application of the method. Regulatory guidelines provide a general framework to assess the validity of a method, but none address the issue of results reliability. In this study, a Bayesian approach is proposed to address this concern. Results reliability is defined here as “the probability of an analytical method to provide analytical results within predefined acceptance limits around their reference or conventional true concentration values over a defined concentration range and under given environmental and operating conditions.” By providing the minimum reliability probability needed for the subsequent routine application of the method, as well as specifications or acceptance limits , the proposed Bayesian approach provides the effective probability of obtaining reliable future analytical results over the whole concentration range investigated. This is summarized in a single graph: the reliability profile. This Bayesian reliability profile is also compared to two frequentist approaches, the first one derived from the work of Dewé et al. [Dewé W., Govaerts B., Boulanger B., Rozet E., Chiap P., Hubert Ph., Chemometr. Intell. Lab. Syst. 85 (2007) 262-268] and the second proposed by Govaerts et al. [B. Govaerts, W. Dewé, M. Maumy, B. Boulanger, Qual. Reliab. Engng. Int. 24 (2008) 667-680]. Furthermore, to illustrate the applicability of the Bayesian reliability profile, this approach is also applied here to a bioanalytical method dedicated to the determination of ketoglutaric acid (KG) and hydroxymethylfurfural (HMF) in human plasma by SPE-HPLC-UV. [less ▲]

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See detailModels to estimate overall analytical measurements uncertainty: assumptions, comparisons and applications
Rozet, Eric ULg; Rudaz, S.; Marini Djang'Eing'A, Roland ULg et al

in Analytica Chimica Acta (2011), 702

Evaluation of analytical results reliability is of core importance as crucial decisions are taken with them. From the various methodologies to evaluate the fitness of purpose of analytical methods ... [more ▼]

Evaluation of analytical results reliability is of core importance as crucial decisions are taken with them. From the various methodologies to evaluate the fitness of purpose of analytical methods, overall measurement uncertainty estimation is more and more applied. Overall measurement uncertainty allows to combine simultaneously the remaining systematic influences to the random sources of uncertainty and allows assessing the reliability of results generated by analytical methods. However there are various interpretations on how to estimate overall measurement uncertainty, and thus various models for estimating it. Each model together with its assumptions has great impacts on the risks to abusively declare that analytical methods are suitable for their intended purpose. This review paper aims at i) summarizing the various models used to estimate overall measurement uncertainty, ii) provide their pros and cons, iii) review the main areas of application and iv) as a conclusion provide some recommendations when evaluating overall measurement uncertainty. [less ▲]

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See detailGuidelines and Validation Issues in Pharmaceutical Analysis
Rozet, Eric ULg; Rudaz, S.

Conference (2010, June 16)

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See detailUniversal applicability of Total Error for the validation of bioanalytical methods
Rozet, Eric ULg; Boulanger, Bruno ULg; Rudaz, S. et al

Conference (2009)

An innovative universal strategy using Total Error is thus proposed to decide about the method’s validity that controls the risk of accepting an unsuitable assay together with the ability to predict the ... [more ▼]

An innovative universal strategy using Total Error is thus proposed to decide about the method’s validity that controls the risk of accepting an unsuitable assay together with the ability to predict the reliability of future results. Several examples of applications of this validation methodology to various types of assays [LC-MS, ELISA, Bio-Assays] will be presented. [less ▲]

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See detailTotal Error for the validation of bioanalytical methods
Rozet, Eric ULg; Boulanger, Bruno ULg; Rudaz, S. et al

Conference (2009)

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See detailEvaluation of decision methodologies for analytical method validation
Rozet, Eric ULg; Rudaz, S.; Bouabidi, A. et al

Poster (2009)

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See detailTotal Error for the Valildation of Bioanalytical methods
Rozet, Eric ULg; Boulanger, Bruno ULg; Rudaz S et al

in Annales de Toxicologie Analytique (2009), 21(S1), 35

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See detailLC method for the determination of R-timolol in S-timolol maleate: Validation of its ability to quantify and uncertainty assessment
Marini Djang'Eing'A, Roland ULg; Chiap, Patrice ULg; Boulanger, Bruno ULg et al

in Talanta (2006), 68(4), 1166-1175

This article presents the validation results of a chiral liquid chromatographic (LC method previously developed for the quantitative determination of R-timolol in S-timoloi maleate samples. A novel ... [more ▼]

This article presents the validation results of a chiral liquid chromatographic (LC method previously developed for the quantitative determination of R-timolol in S-timoloi maleate samples. A novel validation strategy based on the accuracy profiles was used to select the most appropriate regression model, to assess the method accuracy within well defined acceptance limits and to determine the limits of quantitation as well as the concentration range. The validation phase was completed by the investigation of the risk profiles of various acceptable regression models in order to ensure the risk of obtaining the future measurements outside the acceptance limits fixed a priori. On the other hand, the present paper also shows how data used in this validation approach can be used to estimate the measurement uncertainty. The uncertainty derived from P-expectation tolerance interval (sigma-(2)(Tol)), which is equal to the uncertainty of measurements as well as the expanded uncertainty (U-x) using a coverage factor k = 2 was estimated. The uncertainty estimates obtained from validation data were finally compared with those obtained from interlaboratory and robustness studies. (c) 2005 Elsevier B.V. All rights reserved. [less ▲]

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See detailLC method for the determination of R-timolol in S-timolol maleate: Validation of its ability to quantify and uncertainty assessment.
Marini Djang'Eing'A, Roland ULg; Chiap, Patrice ULg; Boulanger, Bruno ULg et al

in Talanta (2006), 68(4), 1166-75

This article presents the validation results of a chiral liquid chromatographic (LC) method previously developed for the quantitative determination of R-timolol in S-timolol maleate samples. A novel ... [more ▼]

This article presents the validation results of a chiral liquid chromatographic (LC) method previously developed for the quantitative determination of R-timolol in S-timolol maleate samples. A novel validation strategy based on the accuracy profiles was used to select the most appropriate regression model, to assess the method accuracy within well defined acceptance limits and to determine the limits of quantitation as well as the concentration range. The validation phase was completed by the investigation of the risk profiles of various acceptable regression models in order to ensure the risk of obtaining the future measurements outside the acceptance limits fixed a priori. On the other hand, the present paper also shows how data used in this validation approach can be used to estimate the measurement uncertainty. The uncertainty derived from beta-expectation tolerance interval (sigma(Tol)(2)), which is equal to the uncertainty of measurements as well as the expanded uncertainty (U(x)) using a coverage factor k=2 was estimated. The uncertainty estimates obtained from validation data were finally compared with those obtained from interlaboratory and robustness studies. [less ▲]

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See detailComparaison de trois approches pour l'estimation de l'incertitude.
Marini Djang'Eing'A, Roland ULg; Chiap, Patrice ULg; Boulanger, Bruno ULg et al

in Acta Clinica Belgica. Supplementum (2006), (1), 60-2

Three different approaches for the estimation of uncertainty measurements using the same analytical method were compared, namely validation, robustness and inter-laboratory studies. The uncertainty ... [more ▼]

Three different approaches for the estimation of uncertainty measurements using the same analytical method were compared, namely validation, robustness and inter-laboratory studies. The uncertainty obtained with the robustness study! predicted well the uncertainty of the inter-laboratory study. On the other hand, the uncertainty estimation obtained with the validation study is lower than those obtained with the two other approaches but is still acceptable as long as the analytical method will be used in a single laboratory. [less ▲]

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