Papers by Béatrice Lalere
The aim of this document is to make recommendations for performing stability studies of parameter... more The aim of this document is to make recommendations for performing stability studies of parameters during the chain of measurement of physico-chemical parameters-organic micropollutants, inorganic and organometallic micropollutants, nutrients and macropolluants in aqueous matrices: surface waters, ground waters, wastewaters (ERU, ERI) and solid matrices: suspended solids (SS), sediments, biota, and sludge. It covers sampling operations, transport operations and laboratory storage operations. The purpose of this document is to: • Define the concepts, the necessary key elements for understanding the stability problem of chemical and physico-chemical parameters in the framework of monitoring programs; • Propose strategies and methodological tools for the implementation of stability studies, by comparing and discussing them; • Propose methodologies to define acceptability criteria for key "parameter-support" couples of interest. The stability period covered by this document co...
Accreditation and Quality Assurance, Jan 13, 2022
The performance of seven amperometric and one colorimetric on-line free chlorine analyzers for mo... more The performance of seven amperometric and one colorimetric on-line free chlorine analyzers for monitoring drinking water were assessed under both controlled and real conditions according to European standard EN 17075 “General requirements and performance test procedures for water monitoring equipment—Measuring devices” (EN 17075. Water quality—General requirements and performance test procedures for water monitoring equipment—Measuring devices. CEN Brussels, 2018). For that purpose, a laboratory test bench was developed and used to estimate under controlled conditions the metrological performances (repeatability, bias, deviation from linearity and limit of quantification) and the influence of factors such as pH and temperature. The expanded measurement uncertainties ( k = 2) calculated from these performances ranged from 6 % to 38 % for amperometric sensors and colorimetric analyzer. A 7-month field trial was conducted to assess the performances under real conditions. The percentile 90 was calculated from 56 relative differences (in absolute value) between the free chlorine concentration measured by the on-line analyzer and the reference value obtained using a colorimetric method with a portable spectrophotometer. The percentiles 90 were found to be in between 10 and 19 % for all analyzers. Moreover, when looking at the continuous monitoring of free chlorine during the 7 months trial, most of the on-line analyzers showed no drift in free chlorine concentration. Control charts were also built as a tool to better monitor performances of sensors and analyzers. The control limits were fixed as the expanded measurement uncertainty of the reference method (e.g., 12 %) and the alarm limits as the expanded measurement uncertainty ( k = 2) of the on-line free chlorine analyze or the maximum percentile 90 obtained under real conditions (e.g., 20 %).
HAL (Le Centre pour la Communication Scientifique Directe), 2017
Pour les besoins du présent document, les définitions et symboles suivants s'appliquent : Approch... more Pour les besoins du présent document, les définitions et symboles suivants s'appliquent : Approche chronologique : Etude de stabilité dont les résultats de mesure sont acquis dans des conditions de fidélité intermédiaire. Approche isochrone : Etude de stabilité dont les résultats de mesure sont acquis dans des conditions de répétabilité.
Clinica Chimica Acta, Jun 1, 2019
Clinica Chimica Acta, May 1, 2022
Journal of Chromatography B, Mar 1, 2017
The present work describes a multi-residue SPE-UPLC-MS/MS method aiming at the characterization o... more The present work describes a multi-residue SPE-UPLC-MS/MS method aiming at the characterization of 68 compounds in natural waters, including parent compounds as well as their major metabolites and glucuronide conjugates. Development was conducted toward the quantitative determination of a broad range of analytes belonging to different class of psychotropic drugs such as benzodiazepines, antidepressants, stimulants, opiates and opioids, anticonvulsants, anti-dementia drugs, analgesic and anti-inflammatory drugs (as anthropic indicators) in the low ngL-1 range of concentration. Satisfactory extraction recoveries >70% were obtained for the majority of analytes (49 out of 68) allowing low limits of quantification. LOQ ranged between 0.1 and 17.8ngL-1 and were lower than 5ngL-1 for 94% of investigated analytes. Furthermore, addition of 25 isotopic labeled standards allowed to ensure reliability of the optimized method. Quantification errors were typically below 15% with relative standard variations <10% in intermediate precision conditions. Finally, the developed method was implemented in natural waters; sampling campaigns were conducted in the Seine River as a demonstration of the applicability and adequation of the method for its purpose. As a result, 48 out of 68 analytes were identified or quantified; some of them like memantine, rivastigmine, zolpidem 4-phenyl-carboxylic acid, zolpidem 6-carboxylic acid for one of the first time in surface waters. Among investigated psychotropic compounds and metabolites, tramadol, codeine, oxazepam, venlafaxine, O-desmethylvenlafaxine, gabapentin, carbamazepine and 10,11-dihydro-10,11-dihydroxycarbamazepine were found to be the most abundant.
Clinical Chemistry and Laboratory Medicine, Feb 24, 2023
Objectives: In clinical pratice, tau protein measurement generally relies on immunoassays (IAs), ... more Objectives: In clinical pratice, tau protein measurement generally relies on immunoassays (IAs), whose major drawback is the lack of results comparability due to differences in selectivity and/or calibration. This underlines the importance of establishing a traceability chain for total tau (t-tau) measurements. The objective of this work is to develop a higher order candidate reference measurement procedure (RMP) for the absolute quantification of t-tau in cerebrospinal fluid (CSF). Methods: To calibrate the candidate RMP and establish metrological traceability to the SI units, a primary calibrator consisting in a highly purified recombinant protein was sourced. Its purity was evaluated by liquid chromatography coupled with high resolution mass spectrometry (LC-HRMS) and the protein mass fraction in solution was certified by amino acid analysis (AAA). An isotopically-labelled homologue was obtained to develop a candidate RMP by isotope dilution mass spectrometry (IDMS) for t-tau absolute quantification in CSF. Calibration blends and quality control (QC) materials were gravimetrically prepared and subjected to the same preparation workflow as CSF samples, followed by LC-HRMS analysis in Parallel Reaction Monitoring (PRM) mode. Results: A primary calibrator has been developed and an IDMS candidate RMP has been validated for CSF t-tau. The candidate RMP was used to certify t-tau concentration in three pools of CSF (low, medium, high). Conclusions: The candidate RMP will pave the road towards global standardization of CSF t-tau measurements. Together with commutable Certified Reference Materials (CRMs), it will allow evaluating and improving the accuracy and comparability of results provided by IAs.
Accreditation and Quality Assurance, Jul 11, 2015
Certified water reference materials are currently not available for most of the hydrophobic organ... more Certified water reference materials are currently not available for most of the hydrophobic organic pollutants listed in the EU Water Framework Directive. To find the most suitable container type for subsequent reference material productions, feasibility studies for the preparation of waters with polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and tributyltin (TBT) close to environmental quality standards in water have been performed. Due to the hydrophobic nature of these compounds and their tendency to adsorb onto container walls, an adequate selection of the most appropriate material for containment, storage and transport of water reference materials is crucial. Three different materials (aluminium, amber glass and fluorinated polyethylene, FPE) and three volumes (500/600 mL, 1000/1200 mL and 2000/3000 mL, depending on commercial availability) were tested at ng L-1 level of the target compounds. FPE shows by far the highest loss of analytes due to adsorption onto the container walls for all compounds studied. Aluminium and glass are equally suited for PAHs and PBDEs, but aluminium is unsuitable as container material for TBT due to acid cleaning requirements. The volume of the containers had no dramatic effect on the adsorption behaviour of target compounds for the different volumes tested.
Analytical and Bioanalytical Chemistry
HAL (Le Centre pour la Communication Scientifique Directe), 2017
Pour les besoins du présent document, les définitions et symboles suivants s'appliquent : Approch... more Pour les besoins du présent document, les définitions et symboles suivants s'appliquent : Approche chronologique : Etude de stabilité dont les résultats de mesure sont acquis dans des conditions de fidélité intermédiaire. Approche isochrone : Etude de stabilité dont les résultats de mesure sont acquis dans des conditions de répétabilité.
Membres du Comité d'Experts Spécialisés (CES) "Evaluation des risques liés aux substance... more Membres du Comité d'Experts Spécialisés (CES) "Evaluation des risques liés aux substances chimiques"info:eu-repo/semantics/publishe
Http Www Theses Fr, 2011
Les Composes Organiques Volatils (COV) font partie des polluants ubiquitaires de notre environnem... more Les Composes Organiques Volatils (COV) font partie des polluants ubiquitaires de notre environnement. Ils sont notamment presents dans les atmospheres interieures a des concentrations souvent superieures a celles rencontrees dans l'air ambiant. Ces composes sont reconnus comme ayant des effets nefastes sur la sante. De nombreuses etudes nationales et internationales ont ainsi vu le jour afin d'en assurer leur suivi dans les espaces clos. La majorite d'entre elles font appel a des methodes analytiques communes : le prelevement sur cartouches adsorbantes et l'analyse par thermodesorption et chromatographie en phase gazeuse. Afin de pouvoir assurer la tracabilite et la comparabilite des analyses, il est indispensable de disposer de references communes : c'est le role des materiaux de reference certifie (MRC) a matrice. Or, peu de MRC, totalement tracables aux unites du Systeme International, contenant des COV a des concentrations rencontrees en espace clos sont disponibles. Les travaux ont consiste a developper une methode de production pour ce type de MRC. Apres avoir developpe, optimise puis valide la methode analytique (thermodesorption / chromatographie en phase gazeuse / detecteur a ionisation de flamme), deux methodes de chargement de cartouches adsorbantes ont ete developpees. Tout d'abord une technique de chargement par vaporisation a permis le chargement de 500 ng ± 5% de benzene. Ensuite, une methode par pompage d'un melange gazeux etalon a permis la production d'un MRC de benzene contenant 500 ng ± 2%. Des etudes de stabilite, d'homogeneite ainsi qu'un essai interlaboratoires ont permis de valider 1 MRC de benzene produit.
Applied Organometallic Chemistry, 1995
New polymer-supported organotin reagents have been prepared. The reducing ability of a polystyren... more New polymer-supported organotin reagents have been prepared. The reducing ability of a polystyrene-supported organotin hydride was evaluated by reaction with haloalkanes. The level of organotin pollution was monitored in comparison with that generated by BuSnH, using ICP-MS analysis.
info:eu-repo/semantics/publishedMembres du Comité d'Experts Spécialisés (CES) "Evaluatio... more info:eu-repo/semantics/publishedMembres du Comité d'Experts Spécialisés (CES) "Evaluation des risques liés aux substances chimiques
HAL (Le Centre pour la Communication Scientifique Directe), May 19, 2016
Analytical and Bioanalytical Chemistry, 2014
One of the unresolved issues of the European Water Framework Directive is the unavailability of r... more One of the unresolved issues of the European Water Framework Directive is the unavailability of realistic water reference materials for the organic priority pollutants at low nanogram-per-liter concentrations. In the present study, three different types of ready-to-use water test materials were developed for polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and tributyltin (TBT) at nanogram-per-liter levels. The first type simulated the dissolved phase in the water and comprised of a solution of humic acids (HA) at 5 mg L −1 dissolved organic carbon (DOC) and a spike of the target compounds. The second type of water sample incorporated the particulate phase in water. To this end, model suspended particulate matter (SPM) with a realistic particle size was produced by jet milling soil and sediments containing known amounts of PAHs, PBDEs and TBT and added as slurry to mineral water. The most complex test materials mimicked "whole water" consequently containing both phases, the model SPM and the HA solution with the target analytes strongly bound to the SPM. In this paper, the development of concepts, processing of the starting materials, characterisation of the HA and model SPMs as well as results for homogeneity and stability testing of the ready-to-use test materials are described in detail.
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Papers by Béatrice Lalere