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See detailDetermination of flurbiprofen enantiomers in plasma using a single-isomer amino cyclodextrin derivative in nonaqueous capillary electrophoresis.
Rousseau, Anne ULg; Pedrini, Matteo; Chiap, Patrice ULg et al

in Electrophoresis (2008), 29(17), 3641-8

A nonaqueous capillary electrophoresis (NACE) assay was developed for the separation and determination of flurbiprofen enantiomers in plasma samples using 6-monodeoxy-6-mono(3-hydroxy)propylamino-beta ... [more ▼]

A nonaqueous capillary electrophoresis (NACE) assay was developed for the separation and determination of flurbiprofen enantiomers in plasma samples using 6-monodeoxy-6-mono(3-hydroxy)propylamino-beta-cyclodextrin as chiral selector. The nonaqueous background electrolyte was made up of 40 mM ammonium acetate in methanol (MeOH), and flufenamic acid was employed as internal standard. Solid-phase extraction was used for sample cleanup prior to the NACE separation.The NACE method reproducibility was optimized by evaluating different capillary washing sequences between runs. After having tested various conditions, trifluoroacetic acid (1 M) in MeOH was finally selected. Concerning the solid-phase extraction procedure, good and reproducible analyte recoveries were obtained using MeOH for protein denaturation and a polymeric phase combining hydrophobic interactions with anion exchange properties (Oasis) MAX) was selected as extraction sorbent. The method selectivity was not only demonstrated toward a blank plasma sample but also toward other non-steroidal anti-inflammatory drugs. The method was then successfully validated with respect to response function, trueness, precision, accuracy, linearity and limit of quantification. [less ▲]

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See detailRisk-Based Approach for the Transfer of Quantitative Methods: Bioanalytical Applications
Rozet, Eric ULg; Dewé, Walthère ULg; Morello, R. et al

in Journal of Chromatography. A (2008), 1189

The transfer of analytical methods from a sending laboratory to a receiving one requires to guarantee that this last laboratory will obtain accurate results. Undeniably method transfer is the ultimate ... [more ▼]

The transfer of analytical methods from a sending laboratory to a receiving one requires to guarantee that this last laboratory will obtain accurate results. Undeniably method transfer is the ultimate step before routine implementation of the method at the receiving site. The conventional statistical approaches generally used in this domain which analyze separately the trueness and precision characteristics of the receiver do not achieve this. Therefore, this paper aims first at demonstrating the applicability of two recent statistical approaches using total error-based criterion and taking into account the uncertainty of the true value estimate of the sending laboratory, to the transfer of bioanalytical methods. To achieve this, they were successfully applied to the transfer of two fully automated liquid chromatographic method coupled on-line to solid-phase extraction. The first one was dedicated to the determination of three catecholamines in human urine using electrochemical detection, and the second one to the quantitation of N-methyl-laudanosine in plasma using fluorescence detection. Secondly, a risk-based evaluation is made in order to understand why classical statistical approaches are not sufficient to provide the guarantees that the analytical method will give most of the time accurate results during its routine use. Finally, some recommendations for the transfer studies are proposed. [less ▲]

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See detailValidation of a nonaqueous capillary electrophoretic method for the enantiomeric purity determination of R-flurbiprofen using a single-isomer amino cyclodextrin derivative
Rousseau, Anne ULg; Chiap, Patrice ULg; Ivanyi, Robert et al

in Journal of Chromatography. A (2008), 1204(2), 219-225

Nonaqueous capillary electrophoresis (NACE) was successfully applied to the enantiomeric purity determination of R-flurbiprofen using 6-monodeoxy-6-mono(2-hydroxy)propylamino-beta-cyclodextrin (IPA-beta ... [more ▼]

Nonaqueous capillary electrophoresis (NACE) was successfully applied to the enantiomeric purity determination of R-flurbiprofen using 6-monodeoxy-6-mono(2-hydroxy)propylamino-beta-cyclodextrin (IPA-beta-CD) as chiral selector. The nonaqueous BGE was made up of 20 mM IPA-beta-CD, 20 mM ammonium camphorsulfortate and 40 mM ammonium acetate in methanol. Flufenamic acid was selected as internal standard. The CE method was carefully optimized in order to prevent the adsorption of the cationic CD onto the capillary wall, and therefore, to avoid loss of peak efficiency and enantioresolution. To achieve this goal, the addition of ammonium camphorsulfonate was found to be necessary. In the selected conditions, the determination of 0.1% of S-flurbiprofen in R-flurbiprofen could be performed using the method of standard additions. The NACE method was then fully validated by applying a novel strategy using accuracy profiles. (c) 2008 Elsevier B.V. All rights reserved. [less ▲]

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See detailHarmonization of strategies for the validation of quantitative analytical procedures - A SFSTP proposal - Part II
Hubert, Philippe ULg; Nguyen-Huu, J.-J.; Boulanger, Bruno ULg et al

in Journal of Pharmaceutical & Biomedical Analysis (2007), 45(1), 70-81

As reported in a previous paper[1], the main objective of the new commission of the Societe Francaise des Sciences et Techniques Pharmaceutiques (SFSTP) was the harmonisation of approaches for the ... [more ▼]

As reported in a previous paper[1], the main objective of the new commission of the Societe Francaise des Sciences et Techniques Pharmaceutiques (SFSTP) was the harmonisation of approaches for the validation of quantitative analytical procedures. In a series of meetings, members of this Commission have first tried to review the objectives of analytical methods and the objectives of validation methods and to recommend the use of two-sided beta-expectation tolerance intervals for total error of validation samples (accuracy profile) in the acceptance/rejection of analytical method in validation phase. In the context of the harmonization, the other objectives were: (i) to propose a consensus on the norms usually recognized, while widely incorporating the ISO terminology; (ii) to recommend to validate the analytical procedure accordingly to the way it will be used in routine; (iii) to elaborate a rational, practical and statistically reliable strategy to assure the quality of the analytical results generated. This strategy has been formalised in a guide and the three latter objectives made by the Commission are summarised in the present paper which is the second part of summary report of the SFSTP commission. The SFSTP guide has been produced to help analysts to validate their analytical methods. It is the result of a consensus between professionals having expertise in analytical and/or statistical fields. The suggestions presented in this paper should therefore help the analyst to design and perform the minimum number validation experiments needed to obtain all the required information to establish and demonstrate the reliability of its analytical procedure. (C) 2007 Elsevier B.V. All rights reserved. [less ▲]

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See detailDevelopment and pre-validation of a high sensitive method for the determination of levonorgestrel in human plasma by SPE/LC/MS-MS
Hubert, Cédric ULg; streel, Bruno; Sibenaler, Renilde et al

Poster (2007, July)

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See detailUsing total error as decision criterion in analytical method transfer
Dewé, Walthère ULg; Govaerts, Bernadette; Boulanger, Bruno ULg et al

in Chemometrics and Intelligent Laboratory Systems (2007), 85(2), 262-268

An analytical transfer is a complete process that consists in transferring a validated analytical method from a sending laboratory (called sender) to a receiving laboratory (called receiver) after having ... [more ▼]

An analytical transfer is a complete process that consists in transferring a validated analytical method from a sending laboratory (called sender) to a receiving laboratory (called receiver) after having experimentally demonstrated that it also masters the method. The decision to transfer an analytical method is usually taken based on the combination of two criteria: one about systematic error and one about random errors. These usual criteria, their combination and their limitations are described in this paper. As it is for method validation, total error-based approaches should be also considered in method transfer. Two approaches are proposed in order to have a total error-based criterion and to take into account the precision of the true value estimate. In the first approach, a beta-expectation tolerance interval similar to the one used in method validation is calculated and then compared to acceptance limits around the estimate of the true value. The second approach, found as slightly more powerful than the first one, consists in estimating the probability to have a result outside these acceptance limits. (c) 2006 Elsevier B.V. All rights reserved. [less ▲]

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See detailNonaqueous capillary electrophoretic behavior of 2-aryl propionic acids in the presence of an achiral ionic liquid - A chemometric approach
Francois, Yannis; Varenne, Anne; Juillerat, Emilie et al

in Journal of Chromatography. A (2007), 1138(1-2), 268-275

Ionic liquids (ILs) appear really attractive as electrolyte additives in nonaqueous capillary electrophoresis (NACE). These salts may offer new possibilities of interactions to modulate analyte effective ... [more ▼]

Ionic liquids (ILs) appear really attractive as electrolyte additives in nonaqueous capillary electrophoresis (NACE). These salts may offer new possibilities of interactions to modulate analyte effective mobilities. The presence of 1-n-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMIM NTf2) in acetonitrile/alcohol background electrolytes (BGEs) was investigated in this work. The aim of this study was to elucidate the influence of the IL concentration on the electrophoretic behavior of four arylpropionic acids and to identify the interactions between the analytes and the 1L cation. The influence on mobility of the IL concentration, the nature and the proportion of the organic solvents, and the concentration of the ionic components of the BGE was first studied by a univariate approach. A four-factor D-optimal experimental design was then applied to provide a deeper insight into analyte interaction with IL cation present both free in BGE and adsorbed onto the capillary wall. (c) 2006 Elsevier B.V. All rights reserved. [less ▲]

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See detailGESTION DU RISQUE LORS DU TRANSFERT DE METHODES ANALYTIQUES – CAS D’UNE METHODE BIOANALYTIQUE
Rozet, Eric ULg; Dewe, W.; Morello, R. et al

Conference (2007)

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See detailDevelopment of a mass spectrometry method for the determination of a melanoma biomarker, 5-S-cysteinyldopa, in human plasma using solid phase extraction for sample clean-up.
Martin, Gaëlle ULg; Chiap, Patrice ULg; Paquet, Philippe ULg et al

in Journal of Chromatography. A (2007), 1156(1-2), 141-8

5-S-cysteinyldopa is a well-known pigment intermediate and analysis of its plasma concentration is interesting for the early diagnosis, as well as for evaluation of treatment and follow-up of malignant ... [more ▼]

5-S-cysteinyldopa is a well-known pigment intermediate and analysis of its plasma concentration is interesting for the early diagnosis, as well as for evaluation of treatment and follow-up of malignant melanoma. A determination method of 5-SCD in human plasma was developed using solid phase extraction (SPE) on disposable cartridges and liquid chromatography electrospray mass spectrometry (LC-ESI-MS-MS). Compound's sensitivity to light and oxidation requires the addition of anti-oxidative agents (AO), to work in acidic media at 4 degrees C and to avoid light exposure of samples since blood collection. Different solid phases involving covalent binding to phenylboronic groups or dual retention mechanisms were evaluated and extraction cartridges containing both hydrophobic and strong cation exchange functionalities were finally selected. The LC separation of 5-SCD from endogenous catecholamines was achieved by gradient elution on a C18 stationary phase. 5-SCD was detected by multiple reaction monitoring (MRM) performed on ES(+) generated ions. Finally, the method was prevalidated in the lower ng/ml range. Good results with respect to accuracy, trueness and precision were obtained. [less ▲]

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See detailEvaluation of Analytical Method Transfer on a Risk Based Methodology using Total Error
Rozet, Eric ULg; Dewe, W.; Govaerts, B. et al

Conference (2007)

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See detailPerformances of a multidimensional on-line SPE-LC-ECD method for the determination of three major catecholamines in native human urine: Validation, risk and uncertainty assessments
Rozet, Eric ULg; Morello, Rosa; Lecomte, Frédéric ULg et al

in Journal of Chromatography. B : Analytical Technologies in the Biomedical & Life Sciences (2006), 844(2), 251-260

A novel, multidimensional on-line SPE-LC method with electrochemical detection is described for the fully automated and direct analysis of the catecholamines norepinephrine, epinephrine and dopamine in ... [more ▼]

A novel, multidimensional on-line SPE-LC method with electrochemical detection is described for the fully automated and direct analysis of the catecholamines norepinephrine, epinephrine and dopamine in urine. The integrated extractive clean-up of the raw biofluid is based on a SPE-column packed with restricted access material (RAM) which is modified with the affinity ligand nitrophenylboronic acid. The method was fully validated according to a recent approach based on an accuracy profile. The acceptance limits were set at +/- 15% of the nominal concentration values. The method was found accurate over a concentration range from 15 to 500 mu g/l for norepinephrine, from 5 to 500 mu g/l for epinephrine and from 50 to 500 mu g/l for dopamine. The relative risk for the use of the validated method in routine analysis was also assessed based on this validation strategy. It was found that at most 3.5% of future sample measurements will fall outside the acceptance limits. This demonstrates the high reliability of the analytical method described. Moreover, the measurements uncertainties were deduced from the validation experiments without any additional effort. (c) 2006 Elsevier B.V. All rights reserved. [less ▲]

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