abstract: Fluorine (F) is a volatile constituent of magmas and hydrous mantle minerals. Compared to other volatile species, F is highly soluble in silicate melts, allowing F to remain in the melt during magma differentiation and rendering F less subject to disturbance during degassing upon magma ascent. Hence, the association between fluorine in basalts and fluorine in the mantle source region is more robust than for other volatile species. The ionic radius of F- is similar to that of OH- and O2-, and F may substitute for hydroxyl and oxygen in silicate minerals and melt. Fluorine is also incorporated at trace levels within nominally anhydrous minerals (NAMs) such as olivine, clinopyroxene, and plagioclase. Investigating the geochemical behavior of F in NAMs provides a means to estimate the pre-eruptive F contents of degassed magmas and to better understand the degassing behavior of H. The partition coefficients of F were determined for clinopyroxene, olivine, plagioclase, and hornblende within melts of olivine-minette, augite-minette, basaltic andesite, and latite compositions. The samples analyzed were run products from previously-published phase-equilibria experiments. Fluorine was measured by secondary ion mass spectrometry (SIMS) using an 16O- primary beam and detection of negative secondary ions (19F-, 18O-, 28Si-). SIMS ion intensities are converted to concentrations by analyzing matrix-matched microanalytical reference materials and constructing calibration curves. For robust F calibration standards, five basaltic glasses (termed Fba glasses) were synthesized in-house using a natural tholeiite mixed with variable amounts of CaF2. The Fba glasses were characterized for F content and homogeneity, using both SIMS and electron-probe microanalysis (EPMA), and used as F standards. The partition coefficients for clinopyroxene (0.04-028) and olivine (0.01-0.16) varied with melt composition such that DF (olivine-minette) < DF (augite-minette) < DF (basaltic andesite) < DF (latite). Crystal chemical controls were found to influence the incorporation of F into clinopyroxene, but none were found that affected olivine. Fluorine partitioning was compared with that of OH within clinopyroxenes, and the alumina content of clinopyroxene was shown to be a strong influence on the incorporation of both anions. Fluorine substitution into both olivine and clinopyroxene was found to be strongly controlled by melt viscosity and degree of melt polymerization. / Dissertation/Thesis / Ph.D. Geological Sciences 2012

Made available in DSpace on 2016-08-19T12:56:47Z (GMT). No. of bitstreams: 1 Dissertacao MARCOS MOURA SILVA.pdf: 1156096 bytes, checksum: fba27f9f64081930b5c5d7149906ff4e (MD5) Previous issue date: 2014-03-28 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The use of certified reference materials is an alternative that laboratories have to ensure the quality of their analyzes. Many laboratories have been investing in the production of their own reference materials in-house. This study presents the application of an interlaboratory test on the certification of Fe, Ca, Si, Ni, Na, P and V in a sample of carbon electrodes candidate reference material in-house, from an aluminum industry in Brazil. The sample was crushed, milled and quartered. Subsequently, the material was filled into 128 botlles. Homogeneity tests were conducted on material that testified that the material remained homogeneous after preparation and stable over time of study. The material certification was made through a collaborative program which included the participation of seven laboratories in different locations. After applying the Cochran and Grubbs tests the values provided by laboratories certified values in ppm were: 589.08 ± 25.28 for Fe, 142.89 ± 12.03 for Ca; 332.03 ± 20.55 to V, 178.07 ± 9.26 for Ni, 326.11 ± 24.07 for Na; 134.17 ± 6.59 for Si and 7.38 ± 1.97 for P. Finally, the laboratories were compared using the z-score test and was observed satisfactory performance, except for the the laboratory 1 for Si analysis, which showed discrepant deviation of the others. The application of variance analysis led to the conclusion that the material was homogeneous and stable enough to be used as a reference material for quality control procedure. / O uso de materiais de referências certificados é uma alternativa que os laboratórios têm para garantir a qualidade de suas análises, razão pela qual muitos deles vêm investindo na produção de seus próprios materiais de referências in-house. Este trabalho apresenta aplicação de um ensaio interlaboratorial na certificação de Fe, Ca, Si, Ni, Na, P e V em uma amostra de eletrodos de carbono, candidata a material de referência in-house, de uma indústria de alumínio no Brasil. Amostras britadas, moídas e quarteadas foram envasadas em 128 frascos. Testes de homogeneidade e estabilidade atestaram que o material manteve-se homogêneo após o envase e estável na sua composição ao longo do tempo de estudo. A certificação do material se deu através de um programa de interlaboratorial que contou com a participação de sete laboratórios em diferentes locais. Após a aplicação dos testes de Cochran e Grubbs aos valores fornecidos pelos laboratórios, os valores certificados em ppm foram: 589,08 ± 25,28 para Fe; 142,89 ± 12,03 para Ca; 332,03 ± 20,55 para V; 178,07 ± 9,26 para Ni; 326,11 ± 24,07 para Na; 134,17 ± 6,59 para Si e 7,38 ± 1,97 para o P. Por fim, os laboratórios foram comparados por meio do teste z-score e observou-se desempenho satisfatório, exceto para o laboratório 1, nas análises de Si, que apresentou desvio discrepante dos demais A aplicação da análise de variâncias aos valores reportados levou a conclusão de que o material era homogêneo e estável o suficiente para ser usado como um material de referência para controle de qualidade interno.

Materiais de Referência (MR) de substâncias químicas têm ampla aplicação, sobretudo na área analítica, servindo de referência para validação de métodos, calibração de instrumentos e controle de qualidade, estabelecendo a comparabilidade de resultados analíticos em escala global e permitindo a transferência da exatidão entre métodos, laboratórios e padrões. Norteado por essas necessidades, o trabalho apresenta uma proposta para certificação de MR baseada nas orientações preconizadas por diretrizes e normas internacionais, principalmente as que seguem o ISO Guia 34, para estabelecer as propriedades certificadas através de técnicas analíticas de Espectrometria de Massas de Alta Resolução, Ressonância Magnética Nuclear, de ¹H e de ¹³C, e de Análise Elementar CHN. A certificação contemplou as caracterizações qualitativa e quantitativa, ensaio de estabilidade e o cálculo da estimativa da incerteza da medição. Como resultado, foi produzido e certificado um lote piloto de MR de &#946;-N-metilamino-alanina (BMAA), uma toxina obtida in-house através de síntese química e purificação, cujos valores de propriedades certificadas foram rastreáveis ao SI e acompanhadas da estimativa da incerteza da medição. / Reference Materials (RM) of chemicals have wide application, particularly in the analyses, providing a reference for validation of methods, instrument calibration and quality control, establishing the comparability of analytical results on a global scale and enabling the transfer of accuracy between methods, laboratories and standards. Guided by these requirements, the paper presents a proposal for certification of MR based on the guidelines recommended by international guidelines and standards, especially those which follow the ISO Guide 34, to establish the certified properties through analytical techniques of mass spectrometry High resolution Nuclear Magnetic Resonance, ¹H and ¹³C, and CHN elemental analysis. The certification included qualitative and quantitative characterization, stability test and the calculation of the estimate of measurement uncertainty. As a result, was produced and certified a pilot batch of RM &#946;-N-methylamino-alanine (BMAA), a toxin obtained in-house via chemical synthesis and purification, whose property values are certified and traceable to the SI accompanied by an estimative of the uncertainty of measurement.

A utilização de materiais de referência é uma ferramenta fundamental na obtenção da comparabilidade e rastreabilidade das medições químicas. No presente trabalho foram desenvolvidas todas as etapas necessárias para a preparação, caracterização e certificação de um material de referência de rim bovino segundo os requisitos aceitos internacionalmente. Dado que o uso pretendido do material de referência é o controle de qualidade de produtos cárneos, alguns elementos com relevância nutricional ou que poderiam constituir contaminantes alimentares potenciais foram escolhidos para serem determinados. Foi estudada a homogeneidade do material tanto dentro quanto entre os diversos frascos preparados e a estabilidade do material em diferentes temperaturas e tempos, obtendo resultados satisfatórios. Para poder abarcar todos os elementos de interesse, os estudos de homogeneidade e estabilidade foram realizados utilizando-se três técnicas analíticas diferentes, análise por ativação neutrônica, espectrometria de massa com fonte de plasma acoplada indutivamente e espectrometria de absorção atômica de vapor frio. Para a avaliação dos estudos de homogeneidade e estabilidade foram utilizadas técnicas estatísticas univariadas clássicas como os testes de análise de variâcia e de regressão, e técnicas de análise multivariada como análise de componentes principais e análise de agrupamento hierárquico. Para atribuir valores às concentrações dos elementos de interesse, foi organizada uma comparação interlaboratorial com 33 laboratórios participantes, tanto de Brasil quanto do exterior. A avaliação conjunta dos resultados da comparação interlaboratorial e dos estudos de homogeneidade e estabilidade realizados possibilitou atribuir valores a 20 elementos com suas respectivas incertezas, sendo 9 valores certificados (As, Cu, Fe, K, Mg, Mn, Na, Se e Zn), 10 valores indicativos (Br, Ca, Cd, Cl, Co, Cs, Hf, Mo, P e Rb) e 1 como informação adicional (Hg). / The use of reference materials is a fundamental tool in obtaining comparability and traceability of chemical measurements. In the present work, all necessary steps for the preparation, characterization and certification of bovine kidney reference material were developed according to internationally accepted requirements. Since the intended use of the reference material is the quality control of meat products, some elements of nutritional relevance or that could constitute potential food contaminants have been chosen to be determined. Between and within bottle homogeneity of the material was assessed as well as its stability at different temperatures and times, obtaining satisfactory results. In order to cover all elements of interest, homogeneity and stability studies were performed using three different analytical techniques, neutron activation analysis, inductively coupled plasma mass spectrometry and cold vapor atomic absorption spectrometry. For the evaluation of the homogeneity and stability studies, classical univariate statistical techniques such as analysis of variance and regression analysis were used. Multivariate analysis such as principal component analysis and hierarchical cluster analysis were used as complementary techniques. To assign values to the concentrations of the elements of interest, an interlaboratory comparison was organized with 33 participating laboratories, both from Brazil and abroad. From the overall evaluation of the interlaboratory comparison results and the homogeneity and stability studies, it was possible to assign values to 20 elements with their respective uncertainties, being 9 certified values (As, Cu, Fe, K, Mg, Mn, Na, Se and Zn), 10 indicative values (Br, Ca, Cd, Cl, Co, Cs, Hf, Mo, P and Rb) and 1 as additional information (Hg).

A utilização de materiais de referência é uma ferramenta fundamental na obtenção da comparabilidade e rastreabilidade das medições químicas. No presente trabalho foram desenvolvidas todas as etapas necessárias para a preparação, caracterização e certificação de um material de referência de rim bovino segundo os requisitos aceitos internacionalmente. Dado que o uso pretendido do material de referência é o controle de qualidade de produtos cárneos, alguns elementos com relevância nutricional ou que poderiam constituir contaminantes alimentares potenciais foram escolhidos para serem determinados. Foi estudada a homogeneidade do material tanto dentro quanto entre os diversos frascos preparados e a estabilidade do material em diferentes temperaturas e tempos, obtendo resultados satisfatórios. Para poder abarcar todos os elementos de interesse, os estudos de homogeneidade e estabilidade foram realizados utilizando-se três técnicas analíticas diferentes, análise por ativação neutrônica, espectrometria de massa com fonte de plasma acoplada indutivamente e espectrometria de absorção atômica de vapor frio. Para a avaliação dos estudos de homogeneidade e estabilidade foram utilizadas técnicas estatísticas univariadas clássicas como os testes de análise de variâcia e de regressão, e técnicas de análise multivariada como análise de componentes principais e análise de agrupamento hierárquico. Para atribuir valores às concentrações dos elementos de interesse, foi organizada uma comparação interlaboratorial com 33 laboratórios participantes, tanto de Brasil quanto do exterior. A avaliação conjunta dos resultados da comparação interlaboratorial e dos estudos de homogeneidade e estabilidade realizados possibilitou atribuir valores a 20 elementos com suas respectivas incertezas, sendo 9 valores certificados (As, Cu, Fe, K, Mg, Mn, Na, Se e Zn), 10 valores indicativos (Br, Ca, Cd, Cl, Co, Cs, Hf, Mo, P e Rb) e 1 como informação adicional (Hg). / The use of reference materials is a fundamental tool in obtaining comparability and traceability of chemical measurements. In the present work, all necessary steps for the preparation, characterization and certification of bovine kidney reference material were developed according to internationally accepted requirements. Since the intended use of the reference material is the quality control of meat products, some elements of nutritional relevance or that could constitute potential food contaminants have been chosen to be determined. Between and within bottle homogeneity of the material was assessed as well as its stability at different temperatures and times, obtaining satisfactory results. In order to cover all elements of interest, homogeneity and stability studies were performed using three different analytical techniques, neutron activation analysis, inductively coupled plasma mass spectrometry and cold vapor atomic absorption spectrometry. For the evaluation of the homogeneity and stability studies, classical univariate statistical techniques such as analysis of variance and regression analysis were used. Multivariate analysis such as principal component analysis and hierarchical cluster analysis were used as complementary techniques. To assign values to the concentrations of the elements of interest, an interlaboratory comparison was organized with 33 participating laboratories, both from Brazil and abroad. From the overall evaluation of the interlaboratory comparison results and the homogeneity and stability studies, it was possible to assign values to 20 elements with their respective uncertainties, being 9 certified values (As, Cu, Fe, K, Mg, Mn, Na, Se and Zn), 10 indicative values (Br, Ca, Cd, Cl, Co, Cs, Hf, Mo, P and Rb) and 1 as additional information (Hg).

Materiais de Referência (MR) de substâncias químicas têm ampla aplicação, sobretudo na área analítica, servindo de referência para validação de métodos, calibração de instrumentos e controle de qualidade, estabelecendo a comparabilidade de resultados analíticos em escala global e permitindo a transferência da exatidão entre métodos, laboratórios e padrões. Norteado por essas necessidades, o trabalho apresenta uma proposta para certificação de MR baseada nas orientações preconizadas por diretrizes e normas internacionais, principalmente as que seguem o ISO Guia 34, para estabelecer as propriedades certificadas através de técnicas analíticas de Espectrometria de Massas de Alta Resolução, Ressonância Magnética Nuclear, de ¹H e de ¹³C, e de Análise Elementar CHN. A certificação contemplou as caracterizações qualitativa e quantitativa, ensaio de estabilidade e o cálculo da estimativa da incerteza da medição. Como resultado, foi produzido e certificado um lote piloto de MR de &#946;-N-metilamino-alanina (BMAA), uma toxina obtida in-house através de síntese química e purificação, cujos valores de propriedades certificadas foram rastreáveis ao SI e acompanhadas da estimativa da incerteza da medição. / Reference Materials (RM) of chemicals have wide application, particularly in the analyses, providing a reference for validation of methods, instrument calibration and quality control, establishing the comparability of analytical results on a global scale and enabling the transfer of accuracy between methods, laboratories and standards. Guided by these requirements, the paper presents a proposal for certification of MR based on the guidelines recommended by international guidelines and standards, especially those which follow the ISO Guide 34, to establish the certified properties through analytical techniques of mass spectrometry High resolution Nuclear Magnetic Resonance, ¹H and ¹³C, and CHN elemental analysis. The certification included qualitative and quantitative characterization, stability test and the calculation of the estimate of measurement uncertainty. As a result, was produced and certified a pilot batch of RM &#946;-N-methylamino-alanine (BMAA), a toxin obtained in-house via chemical synthesis and purification, whose property values are certified and traceable to the SI accompanied by an estimative of the uncertainty of measurement.

L'anàlisi qualitatiu ha estat sempre molt important en el control antidopatge i constitueix cada cop més una part molt significativa de l'activitat diària d'altres tipus de laboratoris. Tanmateix, no existeixen guies o documents específics per ajudar els laboratoris a implantar sistemes de qualitat quan es disposa d'aquest tipus de mètodes. L'objectiu general d'aquesta tesi ha estat el desenvolupament de les eines necessàries per assegurar la qualitat i fiabilitat dels resultats produïts per mètodes d'anàlisi qualitatius, treballant en tres aspectes fonamentals per a l'assegurament de la qualitat dels resultats als laboratoris d'anàlisi: la validació de mètodes, el control intern de la qualitat, i els exercicis d'intercomparació.S'ha elaborat un protocol de validació, s'ha implantat un sistema de control intern de la qualitat per a mètodes d'anàlisi qualitatius i, finalment, s'han elaborat protocols per a la preparació de mostres que seran utilitzades com a materials d'assaig en exercicis d'intercomparació o com a materials de referència, i per realitzar estudis d'homogeneïtat i d'estabilitat, que han estat aplicats a l'estudi de l'estabilitat de substàncies d'interès en control antidopatge. / Qualitative analysis has been very important in antidoping control and its becoming a significant part of the daily activity of other type of laboratories. However, there is a lack of guidance or specific documents to help laboratories to implement quality assurance systems when using these type of methods. The aim of this thesis has been the development of the necessary tools to ensure the quality and reliability of results released by qualitative analytical methods, working in the three main aspects of quality assurance in the analytical laboratory: method validation, internal quality control and intercomparison exercises.A protocol for method validation has been proposed and an internal quality control system for qualitative methodologies has been established. Finally, protocols for the preparation of samples to be used in intercomparison exercises or as reference materials, including homogeneity and stability studies, have been prepared. These protocols have been applied to study the stability of substances with especial interest in antiodoping control.

Firefighters and asphalt pavers are exposed to polycyclic aromatic hydrocarbons (PAHs) during various work activities. The purpose of this study was to evaluate urinary PAH levels and compare these bio-monitoring levels among firefighters, asphalt pavers, and non-occupationally exposed individuals. The National Institute of Standards and Technology (NIST) urinary PAH levels were used for non-occupationally exposed controls. When compared to the NIST standard for smokers and non-smokers, firefighters demonstrated statistically significant differences in urinary concentration differences for the following metabolites: 2-OH-fluorene, 3-OH-fluorene and 1-OH-pyrene, which were lower in firefighters than the NIST mean for smokers. 1-OH-phenanthrene, 2-OH-phenanthrene and 3-OH-phenanthrene were higher among world trade center exposed firefighters than the NIST mean for smokers. When firefighters were compared to the NIST non-smoker standard, firefighters demonstrated elevated levels in all tested PAH biomarkers due to a mixture of smokers and non-smokers in the firefighter cohort. Asphalt workers had statistically significant higher urinary concentration elevations in 2-OH-fluorene, 1-OH-phenanthrene and 3-OH-phenanthrene as compared to the NIST smoker mean. When asphalt pavers were compared to the NIST non-smoker mean, asphalt pavers had statistically significant increases in all tested PAH biomarkers, with the exception of 2-OH-phenanthrene. While firefighters did not demonstrate a substantial change in urinary PAH metabolite levels compared to control populations of smokers and non-smokers, asphalt pavers experienced concentrations that were in some cases increased by orders of magnitude compared to NIST controls. Future research may be needed to evaluate any potential health risk posted to occupational exposed asphalt pavers.

Auf Basis moderner unabhängiger Analysenmethoden wurden selektive und spezifische Analysenverfahren für die Analytik von Phenolen, unter besonderer Berücksichtigung der Alkylphenole entwickelt, optimiert und teilweise validiert. Es wurden Verfahren für die Hochleistungs-Flüssigchromatographie - Massenspektrometrie (HPLC-MS), Hochleistungs-Flüssigchromatographie - Kernmagnetische Resonanzspektrometrie (HPLC-NMR), Gaschromatographie - Massenspektrometrie (GC-MS) und Kapillarelektrophorese (CE) entwickelt. Die HPLC-MS wurde mit den Atmosphärendrucktechniken "Electrospray Ionization" (HPLC-ESI-MS) und "Atmospheric Pressure Chemical Ionization" (HPLC-APCI-MS) eingesetzt. Die Gaschromatographie wurde in Kopplung zu einem hochauflösenden Massenspektrometer (GC-HRMS) und in Kopplung zu einem niederauflösenden Quadrupol-Spektrometer (GC-LRMS) verwendet. Mit der Kapillarelektrophorese wurden Verfahren in den Modi "Kapillar-Zonen-Elektrophorese (CZE) und "Micellare Electrokinetische Chromatographie (MEKC) mit verschiedenen internen Anreicherungstechniken ("Stacking") entwickelt. Für die Validierung des MEKC-Verfahrens mit interner Anreicherung ("Direktes-MEKC-Stacking") wurde ein Ringversuch organisiert und durchgeführt. Anhand von representativen Modellgemischen wurden die Verfahren geprüft und miteinander verglichen. Die Modellgemische sind reproduzierbar herstellbar; ihre Stabilität und Homogenität wurde abgesichert, so daß sie als synthetische Referenzmaterialien zur laborinternen Qualitätssicherung, zur Methodenbewertung und zum Laboratoriumsvergleich eingesetzt werden können. Anhand von charakteristischen Kenngrößen wie Bestimmungsgrenzen, Selektivität, Zeitaufwand, Kosten und Meßunsicherheiten wurden die Verfahren auf ihre Eignung als Standard- bzw. Referenzverfahren bewertet. Die Verfahren der HPLC-NMR, HPLC-ESI-MS, HPLC-APCI-MS und GC-HRMS können mit unterschiedlichem Einsatzbereich als Referenzverfahren für die Analytik von Phenolen eingesetzt werden. Die GC-HRMS ist dabei das leistungsstärkste Referenzverfahren. Die Verfahren der GC-LRMS und CE ("Direktes-MEKC-Stacking") sind als Standardverfahren geeignet und besitzen alle Voraussetzungen um auch als Normverfahren für die Analytik von Phenolen eingeführt zu werden. / Different selective and specific analysis procedures were developed for the determination of phenol derivatives, in particular alkylphenols, in environmental relevant matrices using High-Performance Liquid Chromatography - Mass Spectrometry (HPLC-MS), High-Performance Liquid Chromatography- Nuclear-Magnetic Resonance Spectrometry (HPLC-NMR), Gas Chromatography- Mass Spectrometry (GC-MS) and Capillary Electrophoresis (CE). HPLC-MS was used with atmospheric pressure ionization techniques, Electrospray Ionization (HPLC-ESI-MS) and Atmospheric Pressure Chemical Ionization (HPLC-APCI-MS). Analysis procedures for GC-MS were developed for a high resolution mass spectrometer (GC-HRMS) and a low resolution benchtop quadrupole mass spectrometer (GC-LRMS). CE was used in the Capillary Zone Electrophoresis (CZE) and Micellar Electrokinetic Chromatography (MEKC) mode with different internal stacking techniques. The MEKC procedure with internal stacking (called "Direct-MEKC-Stacking") was validated by an interlaboratory comparison test. These procedures were tested and optimized using representative model mixtures and the most efficient then validated. The model mixtures were produced reproducably and their stability and homogeneity were demonstrated for the application as synthetic reference materials, e.g. for internal laboratory control, quality assurance or method development. The different analysis procedures were categorized as standard- or reference procedures on the basis of characteristic properties, e.g. detection limits, selectivity, analysis time, cost and uncertainty. HPLC-NMR, HPLC-ESI-MS, HPLC-APCI-MS, GC-HRMS can be used as reference procedures for different fields of use. Best performance can be reached with GC-HRMS. GC-LRMS and "Direct-MEKC-Stacking" can be used as standard procedures for the analysis of phenol derivatives and they fulfill all conditions for their implementation in standardization.

En biologie clinique, il est indispensable de disposer de mesures fiables et comparables dans le temps et entre les laboratoires afin de permettre un dépistage et un suivi appropriés des patients. Pour cela, il est indispensable d’établir leur traçabilité métrologique aux unités du système international notamment par des méthodes de référence primaires ou des matériaux de référence certifiés (MRC) d’ordre supérieur. Ces travaux de thèse ont consisté à développer et valider des méthodes de référence pour le cholestérol total, les triglycérides, le HDL-cholestérol et le LDL-cholestérol. Leur valeur ajoutée par rapport à une valeur consensuelle a été démontrée lors d’évaluations externes de la qualité. Elles ont également permis de certifier un MRC qui pourra être utilisé pour le contrôle qualité et/ou l’étalonnage des méthodes de routine. Nous avons montré que le MRC était commutable pour la plupart des méthodes de routine pour les différents biomarqueurs, ce qui a permis de l’utiliser pour évaluer leur justesse. Les méthodes de routine avaient généralement tendance à sous-estimer la concentration en triglycérides (en particulier aux valeurs basses) et à surestimer nettement la concentration de cholestérol total et de LDL-cholestérol (en particulier aux concentrations proches du seuil de décision clinique), ce qui se traduit par une augmentation du nombre de faux-positifs (patients traités à tort). Une approche de correction de non commutabilité a également été proposée afin de permettre l’utilisation de matériaux non commutables pour évaluer la justesse. Pour conclure, ces travaux ont démontré l’importance de disposer de méthodes de référence ainsi que de MRC commutables / Reliable measurements in medical biology are essential for early screening and appropriate follow-up of patients. Ensuring metrological traceability of clinical measurements to higher order reference methods or certified reference materials enables to obtain comparable results over time and between different laboratories that could use different methods to quantify the same biomarker.In this study, reference methods were developed and validated for lipid profile biomarkers (total cholesterol, triglycerides, HDL-C, and LDL-C). Their value added in proficiency testing schemes was demonstrated against consensus mean. They were also used to characterize a certified reference material (CRM) that may be used both as quality control and/or calibrator of field methods. The CRM was shown to be commutable for most field methods and lipid profile biomarkers, which proved it was suitable to assess trueness. Results of our multicenter study showed that field methods tend to underestimate triglycerides (particularly at low concentrations) and overestimate total cholesterol and LDL-C (especially around the clinical threshold), resulting in false positives and significant patient misclassifications. An approach of non-commutanility correction was also presented to allow trueness assessment with non-commutable samples. In conclusion, this work highlights the importance of using reference methods and also commutable CRM to rigorously assess accuracy of field methods used in clinical laboratories