[pt] A cromatografia líquida de alta eficiência hifenada por injeção em fluxo com espectrometria de massa com plasma indutivamente acoplado (HPLC-FI-ICP-MS) foi utilizada para investigar vanádio ligado a porfirinas presente em frações de óleo cru. Em primeiro lugar, a amostra de óleo cru foi submetida a um fracionamento por meio de cromatografia líquida preparativa com detecção em UV-Vis, no comprimento de onda da banda Soret da porfirina (400 nm). As frações de porfirina obtidas foram então separadas numa coluna única de 250 mm, no HPLC e eluídas com fases móveis diferentes, metanol ou metanol:tolueno (80:20; v:v). A quantificação de V-porfirinas nas frações eluídas do HPLC foi feita pela medida do isótopo 51V no ICP-MS, usando-se soluções-padrão de octaetil-porfirina de vanádio (VO-OEP), preparados no mesmo solvente usado na fase móvel, e injetados pós-coluna diretamente no plasma. Um padrão de Ge em metanol (20 microgramas L−1) foi utilizado como padrão interno para minimizar interferências não-espectrais, tais como oscilações devido à injeção. O tratamento matemático do sinal com base no algoritmo de suavização do tipo Transformada Rápida de Fourier (FFT) foi utilizado para melhorar a precisão. As concentrações de V como V-porfirinas foram entre 2,7 e 11 mg kg-1 nas frações, valores próximos à concentração total de V nas frações de óleo cru estudadas. / [en] High performance liquid chromatography hyphenated by flow injection to inductively coupled plasma mass spectrometry (HPLC–FI–ICP-MS) was used to investigate vanadium linked to porphyrins present in fractions of crude oil. First, the crude oil sample was submitted to fractionation by preparative liquid chromatography with UV-Vis detection, at the porphyrin Soret band wavelength (400 nm). The obtained porphyrin fractions were then separated in a 250 mm single column, in the HPLC, and eluted with different mobile phases, methanol or methanol:toluene (80:20; v:v). The quantification of V-porphyrins in the fractions eluted from HPLC was carried out by online measuring the 51V isotope in the ICP-MS, against vanadyl octaethylporphine standard solutions (VO-OEP), prepared in the same solvent as the mobile phase, and injected post-column directly into the plasma. A 20 micrograms L−1 Ge in methanol was used as internal standard for minimizing non-spectral interference, such as short-term variations due to injection. The mathematical treatment of the signal based on Fast Fourier Transform (FFT) smoothing algorithm was employed to improve the precision. The concentrations of V as V-porphyrins were between 2.7 and 11 mg kg−1 in the fractions, which were close to the total concentration of V in the fractions of the studied crude oil.

O testemunho de firn IC-6 de 35,06 m de comprimento foi coletado no manto de gelo antártico (81°03’10,1”S e 79°50’09,1”W; 750 m de altitude) no verão austral de 2004/05. Este testemunho foi subamostrado usando um sistema de fusão contínua desenvolvido pela equipe do Climate Change Institute (University of Maine – Maine /EUA) em sala limpa (CLASSE 100). As 1380 amostras geradas foram analisadas em baixa, média e alta resolução no espectrômetro de massas Element 2 do CCI para 24 elementos traços (Sr, Cd, Cs, Ba, La, Ce, Pr, Pb, Bi, U, As, Li, Al, S, Ca, Ti, V, Cr, Mn, Fe, Co, Na, Mg e K). O testemunho representa 68 anos (1934 – 2002) de registro, segundo datação relativa baseada na variação sazonal nas concentrações dos elementos Na, Mg, Sr e Ca e dos íons Cl-, Na+ e Mg2+. A taxa de acumulação média para o local de amostragem é calculada em 0,30 m a-1 em Eq. H2O. As concentrações medidas foram consideradas baixas, dentro do esperado para o continente antártico e são similares a de outros estudos. As concentrações são controladas pelas variações climáticas sazonais (verão/inverno), pela distância de transporte e pelas fontes naturais e antrópicas desses aerossóis. Contribuições naturais de poeira continental e solo, oriundas principalmente da região de Patriot Hills, são as principais fontes para os elementos césio, bário, alumínio, titânio, vanádio, cromo, ferro, cobalto, manganês e terras raras. Os aerossóis marinhos, oriundos da superfície da cobertura de gelo marinho e transportados pelas massas de ar são fontes importantes de sódio, magnésio, estrôncio e enxofre. Os elementos lítio, cálcio e potássio apresentaram aportes consideráveis tanto de poeira continental como de aerossóis marinhos. Emissões vulcânicas globais e regionais (Monte Erebus e Ilha Deception) são consideradas importantes fontes de elementos traços. Elementos como vanádio, cromo, manganês, cobalto, bismuto, arsênio, cádmio e chumbo apresentaram uma significativa contribuição dessas fontes, variando desde 20% (chumbo e manganês) até 70% (cádmio e bismuto). Os fluxos de deposição natural de chumbo, cádmio, bismuto e arsênio, representam apenas uma pequena fração do total depositado na neve. Para esses elementos, as atividades antrópicas constituem o principal fator responsável por sua mobilização e transporte. / This dissertation examines a 35.06 m long firn core (IC-6) obtained in the Austral summer of 2004/2005 in the West Antarctic Sheet (at 81°03’10.1”S, 79°50’09.1”W; 750 m above sea level). This core was subsampled using a continuous melting system at the Climate Change Institute (CCI, University of Maine, Orono, Maine, USA) under a Class 100 room conditions. At CCI, 1380 samples went through an Element 2 mass spectrometer to determine (at low, middle and high resolutions) the concentration of 24 trace elements (Sr, Cd, Cs, Ba, La, Ce, Pr, Pb, Bi, U, As, Li, Al, S, Ca, Ti, V, Cr, Mn, Fe, Co, Na, Mg e K). The core records 38 years (1934 – 2002) of snow accumulation, as dated by seasonal variations of Na, Mg, Sr e Ca elements and Cl-, Na+ e Mg2+ ionic concentrations. The calculated mean annual accumulation is 0.30 m yr-1 (in H2O equivalent). Their mean concentrations are low and are similar to the ones found in other Antarctic ice core studies. Trace concentrations are controlled by seasonal variations (summer/winter), transport distance and by natural and anthropogenic sources. Cesium, barium, aluminium, titanium, vanadium, chrome, iron, cobalt, manganese and rare earths come from continental dust (mainly from the nearby Patriot Hills). Marine aerosols, from the pack ice surface and transported by air masses, are the sources for sodium, magnesium, strontium and sulphur. Both continental dust and marine aerosols contribute to the lithium, calcium and potassium concentrations. Global and regional (Mount Erebus and Deception Island) volcanic emissions are important trace elements sources, such as vanadium, chrome, manganese, cobalt, bismuth, arsenic, cadmium and lead, varying from 20% (lead and manganese) to 70% (cadmium e bismuth). Trace elements as lead, cadmium, bismuth e arsenic from natural sources have a minor contribution in the samples, human activities are thought to be the main cause for their mobilization and transport.

O testemunho de firn IC-6 de 35,06 m de comprimento foi coletado no manto de gelo antártico (81°03’10,1”S e 79°50’09,1”W; 750 m de altitude) no verão austral de 2004/05. Este testemunho foi subamostrado usando um sistema de fusão contínua desenvolvido pela equipe do Climate Change Institute (University of Maine – Maine /EUA) em sala limpa (CLASSE 100). As 1380 amostras geradas foram analisadas em baixa, média e alta resolução no espectrômetro de massas Element 2 do CCI para 24 elementos traços (Sr, Cd, Cs, Ba, La, Ce, Pr, Pb, Bi, U, As, Li, Al, S, Ca, Ti, V, Cr, Mn, Fe, Co, Na, Mg e K). O testemunho representa 68 anos (1934 – 2002) de registro, segundo datação relativa baseada na variação sazonal nas concentrações dos elementos Na, Mg, Sr e Ca e dos íons Cl-, Na+ e Mg2+. A taxa de acumulação média para o local de amostragem é calculada em 0,30 m a-1 em Eq. H2O. As concentrações medidas foram consideradas baixas, dentro do esperado para o continente antártico e são similares a de outros estudos. As concentrações são controladas pelas variações climáticas sazonais (verão/inverno), pela distância de transporte e pelas fontes naturais e antrópicas desses aerossóis. Contribuições naturais de poeira continental e solo, oriundas principalmente da região de Patriot Hills, são as principais fontes para os elementos césio, bário, alumínio, titânio, vanádio, cromo, ferro, cobalto, manganês e terras raras. Os aerossóis marinhos, oriundos da superfície da cobertura de gelo marinho e transportados pelas massas de ar são fontes importantes de sódio, magnésio, estrôncio e enxofre. Os elementos lítio, cálcio e potássio apresentaram aportes consideráveis tanto de poeira continental como de aerossóis marinhos. Emissões vulcânicas globais e regionais (Monte Erebus e Ilha Deception) são consideradas importantes fontes de elementos traços. Elementos como vanádio, cromo, manganês, cobalto, bismuto, arsênio, cádmio e chumbo apresentaram uma significativa contribuição dessas fontes, variando desde 20% (chumbo e manganês) até 70% (cádmio e bismuto). Os fluxos de deposição natural de chumbo, cádmio, bismuto e arsênio, representam apenas uma pequena fração do total depositado na neve. Para esses elementos, as atividades antrópicas constituem o principal fator responsável por sua mobilização e transporte. / This dissertation examines a 35.06 m long firn core (IC-6) obtained in the Austral summer of 2004/2005 in the West Antarctic Sheet (at 81°03’10.1”S, 79°50’09.1”W; 750 m above sea level). This core was subsampled using a continuous melting system at the Climate Change Institute (CCI, University of Maine, Orono, Maine, USA) under a Class 100 room conditions. At CCI, 1380 samples went through an Element 2 mass spectrometer to determine (at low, middle and high resolutions) the concentration of 24 trace elements (Sr, Cd, Cs, Ba, La, Ce, Pr, Pb, Bi, U, As, Li, Al, S, Ca, Ti, V, Cr, Mn, Fe, Co, Na, Mg e K). The core records 38 years (1934 – 2002) of snow accumulation, as dated by seasonal variations of Na, Mg, Sr e Ca elements and Cl-, Na+ e Mg2+ ionic concentrations. The calculated mean annual accumulation is 0.30 m yr-1 (in H2O equivalent). Their mean concentrations are low and are similar to the ones found in other Antarctic ice core studies. Trace concentrations are controlled by seasonal variations (summer/winter), transport distance and by natural and anthropogenic sources. Cesium, barium, aluminium, titanium, vanadium, chrome, iron, cobalt, manganese and rare earths come from continental dust (mainly from the nearby Patriot Hills). Marine aerosols, from the pack ice surface and transported by air masses, are the sources for sodium, magnesium, strontium and sulphur. Both continental dust and marine aerosols contribute to the lithium, calcium and potassium concentrations. Global and regional (Mount Erebus and Deception Island) volcanic emissions are important trace elements sources, such as vanadium, chrome, manganese, cobalt, bismuth, arsenic, cadmium and lead, varying from 20% (lead and manganese) to 70% (cadmium e bismuth). Trace elements as lead, cadmium, bismuth e arsenic from natural sources have a minor contribution in the samples, human activities are thought to be the main cause for their mobilization and transport.

Inductively coupled plasma mass spectrometry is a well-established technique for the measurement of isotope ratios. Double focussing mass analysers enable increased resolution to be applied to separate spectroscopic interferences, or the use of multi-collector detection techniques for high precision isotope ratio determinations. For the Central Science Laboratory (CSL), trace elements team, methods were developed for Zn and Fe isotope ratio measurements in acid digested faecal samples from a human nutritional study. For Zn, a novel high resolutionlmulticollector combination was employed; for Fe a single collector, high resolution method was used. In both cases, samples from the nutritional study known to contain the analytes in natural isotopic abundance were used to correct for the mass bias. Two independent methods for determining Zn and Fe isotope ratios were used to validate the measurement strategies. The team at CSL are also involved in the authentication of food products. Isotope ratio and elemental concentration data were used to determine the geographical origin of rice samples, and to distinguish between traditional and modem Basmati rice grown in India and Pakistan. NERC Isotope Geosciences Laboratory are primarily concerned with the achievable accuracy and precision of an isotope ratio measurement. Use of a mass bias correction expression appropriate to the ICP-MS instrument is essential for high quality isotope ratio measurements. Cd and Sn were used to study the variation of the mass bias in a double focussing ICP-MS system with time, absolute mass and mass difference. It was proposed that mass bias should be considered as a result of the change in the instrument response with mass, and not a fundamental parameter in its own right. A method for determination of the best mass bias correction model for an individual instrument, through examination of the instrument response function was developed.

The determination of the isotopic composition of single uranium oxide particles, size 0.3-2 μm, for nuclear safeguards is current performed by either thermal ionisation mass spectrometry (TIMS) or Secondary Ion Mass Spectrometry (SIMS). Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS), a well-established analytical technique for determining the isotopic composition of solid materials, has the potential to be another method by which single uranium oxide particles can be analysed, complementing established protocol, but requires optimisation. In this study the ability of LA-ICP-MS to determine the isotopic composition, principally 234U/238U, 235U/238U and 236U/238U, of glass reference materials and sub-micron uranium oxide particles is investigated. To achieve the best detection efficiency a prototype high-speed ablation cell and injector design, designed previously at Loughborough University, was coupled to a high efficiency multi collector (MC-) ICP-MS. As a result an increase in signal-to-noise ratio and a measured detection efficiency of 5-7% was achieved for a LA-MC-ICP-MS system. The capability of the LA-MC-ICP-MS system, for the determination of the uranium isotopic composition of single particles was compared to a more established low-volume ablation cell. A source of additional uncertainty, blind time arising from incompatibilities with the mixed detector array of the MC-ICP-MS was identified. The impact of the additional uncertainty on isotope ratio analysis was modeled and a method developed to filter out affected data. LA-ICP-MS and LA-MC-ICP-MS were used to successfully determine the uranium isotopic compositions of sub-micron uranium oxide particles, of a known certified composition. A sample planchet containing particles of two distinct isotopic compositions was resolved. The utility of three data evaluation strategies to determine the isotopic composition of single uranium oxide particles was investigated. The necessity and advantages of calculating isotope ratios using the geometric mean is demonstrated, which has application for isotope ratio analysis performed on all forms of mass spectrometry. A novel approach to prepare particulate samples for laser ablation analysis, cytocentrifugation, is described. By using as the solvent, a mixture of nail polish and acetone, dispersed particles are held in a strong film layer thin enough to allow embedded particles to be imaged by SEM-EDX. A sample of uranium oxide particles in an environmental matrix prepared using cytocentrifugation is analysed by LA-MC-ICP-MS and their isotopic composition resolved.

Ces travaux de thèse concernent les développements d'une méthode de séparation chromatographique couplée simultanément à l'ESI-MS et l'ICP-MS afin de réaliser l'analyse de spéciation exhaustive des lanthanides en phase aqueuse représentative des phases de désextraction des procédés de traitement du combustible usé. Cette méthode analytique permet de séparer, caractériser et quantifier des complexes de lanthanides à ligands polyaminocarboxyliques comme le DTPA et l'EDTA, utilisés comme agents complexants dans ces procédés. La méthode de séparation par chromatographie HILIC des complexes de lanthanides a été mise au point avec la phase stationnaire à fonctions amide. Un criblage d'une large gamme de compositions de phase mobile a permis de déterminer que le mécanisme d'adsorption est prédominant lors l'élution des complexes de lanthanides et d'obtenir des conditions de séparation optimisées. Des conditions d'analyse plus rapides obtenues avec une colonne à fonctions amide de granulométrie sub-2 µm et de longueur plus faible ont permis de réduire le temps d'analyse d'un facteur 2,5 et la consommation de solvant de 25 %. La caractérisation structurale et isotopique par HILIC ESI-MS a été réalisée ainsi que la mise au point d'une méthode d'étalonnage externe. Les performances analytiques de la méthode de quantification ont été déterminées. Enfin, le développement d'un système de couplage de l'HILIC à l'ESI-MS et l'ICP-MS a été réalisé. Une méthode de quantification simultanée par ESI-MS et par ICP-MS a permis de déterminer la distribution quantitative des espèces en solution ainsi que les performances analytiques associées. / This work focuses on the development of a chromatographic separation method coupled to both ESI-MS and ICP-MS in order to achieve the comprehensive speciation analysis of lanthanides in aqueous phase representative of back-extraction phases of advanced spent nuclear fuel treatment processes. This analytical method allowed the separation, the characterization and the quantitation of lanthanides complexes holding polyaminocarboxylic ligands, such as DTPA and ETDA, used as complexing agents in these processes. A HILIC separation method of lanthanides complexes has been developed with an amide bonded stationary phase. A screening of a wide range of mobile phase compositions demonstrated that the adsorption mechanism was predominant. This screening allowed also obtaining optimized separation conditions. Faster analysis conditions with shorter amide column packed with sub 2 µm particles reduced analysis time by 2.5 and 25% solvent consumption. Isotopic and structural characterization by HILIC ESI-MS was performed as well as the development of external calibration quantitation method. Analytical performances of quantitation method were determined. Finally, the development of the HILIC coupling to ESI-MS and ICP-MS was achieved. A simultaneous quantitation method by ESI-MS and ICP-MS was performed to determine the species quantitative distribution in solution. Analytical performances of quantitation method were also determined.

La présente étude s’inscrit dans le contexte post-Fukushima et avait pour objectif la mise en place d’une méthode d’analyse pour identifier et quantifier, rapidement, des radionucléides émetteurs alpha et bêta, en situation post-accidentelle, dans les échantillons de l’environnement. La première étape de l’étude a permis de dresser la liste des radio-isotopes émetteurs alpha et bêta susceptibles d’être rejetés dans l’environnement suite à un accident nucléaire. Dans une deuxième étape, un protocole d’analyse rapide a été développé pour 17 radio-isotopes de U, Th, Pu, Am, Np et Sr. L’objectif était d’automatiser l’étape de séparation radiochimique et de la coupler à la mesure. La séparation est réalisée en employant des colonnes contenant les résines d’extraction, TEVA®, TRU et Sr. La mesure est effectuée par ICP-MS (spectrométrie de masse à plasma induit) et dans certains cas par compteur proportionnel à gaz pour quantifier le radiostrontium (89Sr et 90Sr). D’excellentes performances analytiques ont été obtenues, lors de la mesure hors-ligne, pour des échantillons d’eaux (robinet, rivière et mer) et solides (sols et filtres d’aérosols), après une minéralisation par four à micro-ondes ou par fusion alcaline suivie d’une co-précipitation avec Ca3(PO4)2. Ces performances sont caractérisées par des rendements de récupération compris entre 70 % et 100 % et des écarts types entre 5 % et 10 %. Le protocole de séparation a été ensuite automatisé et transposé en mode couplage en ligne avec l’ICP-MS. Les paramètres opératoires ont été optimisés avec un plan d’expériences, défini et exploité avec le logiciel Minitab®. Après optimisation du protocole, l’automatisation et le couplage de la séparation permettent de quantifier rapidement, en 1,5 h par échantillon, U, Th, Pu, Am, Np et Sr et de gagner un facteur 20 sur les limites de détection des radio-isotopes artificiels. / The present study follows the Fukushima power plant accident and aimed to develop an analytical method to achieve, during an emergency situation, a rapid identification and quantification of alpha and beta emitters in environmental samples. The first step of this study allowed us to list the alpha and beta emitters which can be released in the environment in case of a nuclear accident. The second step aimed towards the development of a rapid analysis method to quantify 17 radionuclides of U, Th, Pu, Am, Np and Sr. The main objective was the automation of the radiochemical separation step and its coupling for the measurement. The separation is performed using columns containing extraction resins, namely TEVA®, TRU and Sr. The measurement is performed using an ICP-MS (inductively coupled plasma mass spectrometry) and in some cases a gas proportional counter to quantify radiostrontium (89Sr and 90Sr). Excellent figures of merit were obtained, off line, with water (tap, river and sea water) and solid matrices (soil and aerosol filters), after a micro-wave digestion or an alkaline fusion dissolution followed by a Ca3(PO4)2 coprecipitation. The proposed analytical strategy showed yields between 70 % and 100 % and standard deviations between 5 % and 10 %. The newly developed separation method was then automated and coupled on-line to ICP-MS. The operating parameters were optimized using a design of experiments and the results were processed with Minitab®. The optimized automated separation coupled on-line to the ICP-MS allows the rapid quantification, in 1.5 h per sample, of U, Th, Pu, Am, Np and Sr with detection limits gain as high as 20 times for artificial radionuclides.

Abstract Mercury is a global pollutant that accumulates easily in forest soils, even in remote areas. Mercury accumulated in soils can be subsequently released into surface waters causing an increased eco-toxicological and human health risk. The most toxic form of mercury to humans and wildlife is methyl mercury (MeHg), which can be formed in the environment via methylation processes. In freshwaters, MeHg is readily accumulated in fish, which are the main source of human exposure to MeHg. The determination of both total mercury and MeHg concentrations in environmental samples, such as natural waters and soils, is important in environmental risk assessment. This study involved the development of analytical methods for the determination of ultra-trace total mercury and MeHg concentrations in humic-rich natural water and peat soil samples. Each developed method was carefully optimized and validated by using real natural water and peat soil samples, certified reference materials and/or reference methods. The cold vapor inductively coupled plasma mass spectrometry (CV-ICP-MS) method developed during this study was found to be a reliable method for the determination of total ultra-trace mercury concentrations in natural freshwaters. Purge and trap gas chromatography, coupled to an ICP-MS, was used in mercury speciation analysis. Together with species-specific isotope dilution this technique proved to be a reliable method in MeHg determinations. Prior to instrumental determination, MeHg was successfully isolated from humic-rich water and peat soil samples using N2-assisted distillation. The analytical methods developed in this study were successfully applied to an investigation of the effects of forest harvesting practices on the mobilization of mercury in boreal forest catchments. / Tiivistelmä Elohopeaa pääsee ilmakehään sekä luonnollisista lähteistä (mm. tulivuorenpurkaukset ja kiviaineksen rapautuminen), että ihmisen toiminnan kautta. Elohopean viipymäaika ilmakehässä on hyvin pitkä, minkä vuoksi se voi kulkeutua kauas päästölähteestä ennen päätymistään maaperään ja vesistöihin. Ympäristössä olevasta epäorgaanisesta elohopeasta voi muodostua erittäin myrkyllistä metyylielohopeaa, joka rikastuu helposti ravintoketjussa. Metyylielohopean muodostuminen on merkittävä osa elohopean biogeokemiallista kiertoa, minkä vuoksi metyylielohopean määrittäminen näytteen kokonaiselohopeapitoisuuden ohella antaa tärkeää tietoa elohopean käyttäytymisestä ympäristössä. Tutkimuksessa kehitettiin analyysimenetelmät, joilla määritettiin ultrapieniä kokonaiselohopea- ja metyylielohopeapitoisuuksia humuspitoisista luonnonvesistä ja turvemaanäytteistä. Tutkimuksessa käytetyt näytteet oli kerätty turvemaametsien valuma-alueilta Sotkamosta. Luonnonvesinäytteiden kokonaiselohopeapitoisuuksien määrityksessä käytettiin kylmähöyrymenetelmää (CV) yhdistettynä induktiiviplasma-massaspektrometriaan (ICP-MS). Vesi- ja turvenäytteiden metyylielohopeapitoisuuksien määrityksessä elohopeaspesiekset erotettiin kaasukromatografisesti (GC) ja määritettiin isotooppilaimennus-ICP-MS:lla. Ennen GC-ICP-MS -määritystä näytteet esikäsiteltiin typpiavusteisella tislausmenetelmällä ja esikonsentroitiin ’purge and trap’ -tekniikalla. CV-ICP-MS ja ’purge and trap’ GC-ICP-MS -menetelmät optimoitiin huolellisesti sekä laiteparametrien, että reagenssimäärien suhteen. Menetelmillä saatavien tulosten oikeellisuus varmistettiin vertailumateriaalien ja/tai vertailumenetelmien avulla. Kehitettyjä analyysimenetelmiä hyödynnettiin tutkimuksessa, jossa seurattiin metsähakkuiden mahdollisia vaikutuksia elohopean huuhtoutumiseen ja metyloitumiseen ojitetuilla turvemailla.

Elemental analysis can become an important piece of evidence to assist the solution of a case. The work presented in this dissertation aims to evaluate the evidential value of the elemental composition of three particular matrices: ink, paper and glass. In the first part of this study, the analytical performance of LIBS and LA-ICP-MS methods was evaluated for paper, writing inks and printing inks. A total of 350 ink specimens were examined including black and blue gel inks, ballpoint inks, inkjets and toners originating from several manufacturing sources and/or batches. The paper collection set consisted of over 200 paper specimens originating from 20 different paper sources produced by 10 different plants. Micro-homogeneity studies show smaller variation of elemental compositions within a single source (i.e., sheet, pen or cartridge) than the observed variation between different sources (i.e., brands, types, batches). Significant and detectable differences in the elemental profile of the inks and paper were observed between samples originating from different sources (discrimination of 87 – 100% of samples, depending on the sample set under investigation and the method applied). These results support the use of elemental analysis, using LA-ICP-MS and LIBS, for the examination of documents and provide additional discrimination to the currently used techniques in document examination. In the second part of this study, a direct comparison between four analytical methods (µ-XRF, solution-ICP-MS, LA-ICP-MS and LIBS) was conducted for glass analyses using interlaboratory studies. The data provided by 21 participants were used to assess the performance of the analytical methods in associating glass samples from the same source and differentiating different sources, as well as the use of different match criteria (confidence interval (±6s, ±5s, ±4s, ±3s, ±2s), modified confidence interval, t-test (sequential univariate, p=0.05 and p=0.01), t-test with Bonferroni correction (for multivariate comparisons), range overlap, and Hotelling’s T2 tests. Error rates (Type 1 and Type 2) are reported for the use of each of these match criteria and depend on the heterogeneity of the glass sources, the repeatability between analytical measurements, and the number of elements that were measured. The study provided recommendations for analytical performance-based parameters for µ-XRF and LA-ICP-MS as well as the best performing match criteria for both analytical techniques, which can be applied now by forensic glass examiners.

Cryptic trends in the trace element chemistry of Fe-Ti oxide minerals have been used to elucidate the magmatic processes responsible for the formation of Fe-Ti-V deposits in the Rivière Bell Complex layered mafic-ultramafic intrusion near Matagami, Quebec, Canada. Although metamorphism at greenschist-amphibolite facies conditions has modified the primary igneous compositions of magnetite and ilmenite, their Cr and V contents appear to have been unaffected. Chemostratigraphic variations of these elements in Fe-Ti oxides therefore remain valid tracers of magmatic differentiation, even in metamorphosed settings. Injections of compositionally evolved, Fe-Ti oxide-laden magma into a more primitive ferrogabbroic host are presumably responsible for sharp decreases in the Cr and V concentrations of Fe-Ti oxides that coincide with lithostratigraphic changes from predominantly disseminated gabbros to ultramafic sequences closely interlayered with massive oxides. These injections highlight the multistage magmatic history of the layered series of the Rivière Bell Complex and its vanadium ore horizons.