Na porção W-SW do lobo Guaxupé, pertencente à Nappe Socorro-Guaxupé, nos arredores da cidade de São José do Rio Pardo, é registrado um evento metamórfico e anatético de fácies granulito, sob condições de desidratação da hornblenda, com T >=850ºC. As rochas diatexíticas, que compõem as suítes São José do Rio Pardo (SJRP) e Pinhal, resultam desse evento de alta temperatura, ocorrido há ~625 Ma. As assinaturas geoquímicas e isotópicas sugerem uma geração a partir da anatexia da crosta continental inferior. Além disso, o enriquecimento em potássio da suíte SJRP indica uma afinidade vaugnerítica, a qual é caracterizada por altos conteúdos de Mg, elementos do tipo LILE (large ion lithophile elements), HFSE (high field strenght elements) e ETR-leves, além de valores negativos de \'épsilon\'Nd e razões de Sr iniciais baixas, ~0.706. O magmatismo vaugnerítico implica em um manto litosférico metassomatizado como fonte, o qual foi enriquecido por eventos de subducção precedentes. A presença de pseudomorfos de fusão nesses diatexitos indicam uma evolução quase isotérmica sob presença de líquido anatético. O transporte sin-magmático ocorreu para NE-E. A fonte de calor para esse metamorfismo pode estar associada à delaminação da base do arco magmático. O processo de fusão parcial gerou leucossomas charno-enderbíticos na Unidade Metatexítica, com assinaturas geoquímicas e isotópicas que indicam uma fonte crustal. Dessas rochas, foram separados cristais de zircão que mostraram duas populações distintas. A primeira, tipicamente com cristais prismáticos e bipiramidados, indicam idades em torno de 620 Ma, enquanto que a segunda, com cristais isométricos típicos de alto grau metamórfico, indicam idades em torno de 610 Ma. Em relação ao pico metamórfico de ~625 Ma, as idades mais jovens obtidas sugerem um período de 15 my em que predominaram altas temperaturas. O transporte tectônico para NW, em estado sólido de alta temperatura, é posterior à cinemática sin-magmática para NE, e deve estar associado à compressão da placa superior convergente, dentro desse período de alta temperatura. Esse regime tectônico é compatível com modelos recentes da tectônica Andina onde é descrita uma subducção horizontal (Pampean flat subduction). Dentre as rochas da Unidade Granulítica Basal, também submetida à fusão parcial por desidratação da hornblenda, ocorrem gnaisses com afinidade adakítica, sugerida pelas altas razões Sr/Y = 72.73, La/Yb = 23.07, \'(La/Yb) IND.N\' = 15.56, e teores de #mg = 51.77, Sr = 1062 ppm, Cr = 197 ppm e Ni = 103 ppm. Tal afinidade sugere magmas resultantes da fusão de um slab em subducção. A Nappe Socorro-Guaxupé admite uma evolução que se inicia, cerca de 670-640 Ma, com uma subducção inclinada para a geração de rochas cálcio-alcalinas com alguns membros adakíticos. É seguido um momento de colisão, entre 625 e 610 Ma, com a geração de rochas diatexíticas e metatexíticas de alto potássio, onde o arco migrou primeiramente para o ante-arco (estado subsólido) e depois em direção ao interior da placa superior (estado sólido). A estabilização da nappe se deu quando da colocação dos maciços sieníticos pós-tectônicos, Capituva e Pedra Branca. / The W-SW portion of the Guaxupé Domain, nearby the São José do Rio Pardo city, records a granulite facies anatetic event under hornblende dehydration-melting conditions, i.e. T >=850ºC. The diatexitic rocks that are comprised within the São José do Rio Pardo and Pinhal suites resulted from this high-T metamorphic event, ca. 625 Ma. Geochemical and isotopic signatures suggest derivation from the lower continental crust. The K-rich SJRP suite also show geochemical affinity with vaugneritic rocks, suggested by high contents of Mg, LILE, HFSE and light-REE in addition to negative ?Nd and low Sr initial ratio (~0.706). Vaugneritic magmatism implies on a derivation from a metasomatized lithospheric mantle source enriched before partial melting in a previous subduction setting. Once both suites contain melt pseudomorphs, it is then suggested and isothermic evolution under the presence of melt. A syn-magmatic driven transport occurred towards NE-E, and the heat source for high-T conditions could be assigned to mantle delamination under the margmatic arc. Within the Metatexitic Unit, partial melting resulted in charno-enderbitic leucosomes whose geochemical and isotopic signatures indicate crustal sources. From these leucosomes, two different populations of zircon crystals were separated. The first, comprising bypiramidal-prismatic grains, yield ages around 620 Ma, whereas the second typology of zircons is isometric and soccer-ball type, yielding younger ages around 610 Ma. The latter typology is typical of high-T and melt-bearing rocks. Considering the 625 Ma metamorphic peak, the younger ages suggest a 15 my period when high-T conditions prevailed. Top-to-NW transport, under solid-state high-T conditions, can be associated to the compression of the upper convergent plate within this high-T period. Textural features suggest this transport to have occurred after the crystallization of the syn-magmatic rocks. The compression of the upper plate resembles recent models of the Andean orogenic cycle, where the Pampean flat subduction is described. Among the rocks of the Basal Granulitc Unit, which also underwent hornblende-dehydration partial melting, a gneissic rock shows adakitic affinity, suggested by Sr/Y = 72.73, La/Yb = 23.07, \'(La/Yb) IND.N\' = 15.56, #mg = 51.77, Sr = 1062 ppm, Cr = 197 ppm and Ni = 103 ppm. Adakitic magmas are thought to be slab melts. The Socorro-Guaxupé Nappe was built up between 670 and 640 Ma with a steep subduction and generation of calc-alkaline and subordinate adakitic rocks. A collisional setting, generating high-K diatexites and metatexites, took place between 625 and 610 Ma, where the arc firstly migrated (in subsolidus state) towards the forearc and then migrated (in solid state) towards the interior of the upper plate. Post-tectonic Capituva and Pedra Branca syenitic plutons intruded around 610 Ma, recording the arc migration ceasing.

La datation de l’âge de génération des hydrocarbures et de la déposition de la roche mère fournit des informations importantes dans la prospection pétrolière. Dans ce travail, différentes stratégies ont été étudiées pour la détermination des métaux traces, et des rapports isotopiques du plomb dans des produits pétroliers par des techniques de spectrométrie de masse. Les stratégies d’analyses développées dans ce travail ont été utilisées pour estimer l’âge de génération du pétrole, ainsi que l’âge de déposition de la roche mère âge du « New Albany shales » dans le basin d’Illinois, en utilisant les géochronomètres U-Th-Pb. Les ages déterminés par la méthode U-Th-Pb sont en très bon accord avec ceux prédits par les modèles numériques géologiques, ce qui démontre le potentiel de cette approche pour étudier l’histoire de la formation des hydrocarbures et dans la recherche de nouvelles sources d'hydrocarbures. / Timing crude oil generation and source rock deposition provides important clues in petroleum prospection. In this work, different analytical procedures were developed for trace metals and Pb isotope ratio were determination crude oils and related products. These analytical strategies were then used, for the first time, to assess the applicability of the U-Th-Pb geochronometers for timing source rock deposition age and crude oil generation in the Illinois Basin. Ages determined are in good agreement with those predicted by geological numerical models, demonstrating the potential of these geochronometers to study the history of hydrocarbons formation and to find new hydrocarbon sources.

La chaine varisque ouest-européenne est une vaste province métallogénique qui abrite une large diversité de minéralisations. Une grande partie d’entre elles ont fait l'objet d'exploitations historiques, à l'instar de Salau(Pyrénées Centrales), le plus important gisement de tungstène français. Les résultats de terrain combinés aux études minéralogiques et géochimiques convergent pour montrer qu'il existe deux types de minéralisations superposées : (1) un skarn à silicates calciques, rare scheelite fine et sulfures disséminés ; (2) une brèche filonienne à sulfures massifs (pyrrhotite et chalcopyrite dominante), or et abondante scheelite grossière qui a constitué l’essentiel du minerai exploité. Cette brèche se localise dans des zones de cisaillement ductile-fragile(faille Véronique) recoupant la granodiorite. Les datations U/Pb sur zircon, apatite et scheelite situent le skarn contemporain de l'intrusion de la Fourque à 295±2 Ma alors que la brèche à sulfures massifs se forme environ6 Ma après, à 289±2 Ma. Ces minéralisations, issues de deux intrusions successives (granodiorite puis leucogranite), s’inscrivent dans l'évolution d'un modèle Intrusion Related Deposit. La mise en place de labrèche à forte teneur en or-scheelite est initiée par la focalisation progressive de la déformation régionale dans la Zone axiale des Pyrénées au sein de failles E-W dextres inverses. L'origine de l'or à l'échelle des Pyrénées pourrait s'expliquer en partie par une large répartition de ces minéralisations à forte teneur. La carte de paléotempératures RSCM a permis de localiser d’autres intrusions non affleurantes en étendant le district minéralisé sur plus de 7 km jusqu’à l’indice à W-Au d’Aurenère en Espagne. / The Western European variscan belt is a vast metallogenic district which hosts a wide diversity of mineralizations. A large part of them have been historically exploited, such as Salau (Central Pyrenees), the most important French tungsten deposit. The field results combined with the mineralogical and geochemical studies converge to show that it exists two superimposed ore types: (1) a calcic silicates skarn with rare fine grainedscheelite and disseminated sulphides; (2) a mineralized breccia with massive sulphides (pyrrhotiteand chalcopyrite dominant), gold and abundant coarse-grained scheelite which have constituted the main part of the exploited ore. This breccia is localized in ductile-fragile shear-zones (Veronique fault) which crosscut the granodiorite. U/Pb datings on zircon, apatite and scheelite place the skarn, contemporaneous of the LaFourque intrusion at 295±2 Ma while the massive sulphides breccia was formed ca. 6 Ma later at 289±2 Ma.These mineralizations, from two successive intrusions (granodiorite then leucogranite), belong to the evolution of an Intrusion Related Deposit model. The emplacement of the high grade gold and scheelite breccia was initiated by the progressive focalization of the regional deformation in the Axial Zone of the Pyrenees within EWdextral-reverse faults. The source of gold at the Pyrenees scale could be explained in part by this type of high-grade mineralizations. The RSCM paleo-temperature map has made possible to locate other undercover intrusions, extending the mineralized district over more than 7 km until the W-Au Aurenere occurrence in Spain.

Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O Complexo Juiz de Fora (CJF) na região de Três Rios (RJ) é constituído por uma ampla variedade composicional, tendo desde granitos, tonalitos a rochas de composição gabróica. Através da litogeoquímica pôde-se subdividir essa unidade em 4 conjuntos: (i) cálcioalcalino de alto-K, (ii) cálcioalcalino de médio-K, (iii) toleítico e (iv) alcalino. Pela análise geocronológica (LA-ICPMS, U-Pb) foi obtida a idade de 2,1Ga para o conjunto cácioalcalino de médio-K, duas idades neoproterozóicas (615.9 6.4 Ma e 589.1 5 Ma) foram datadas em um ortogranulito do conjunto toleítico, que foram interpretadas como sendo idades de metamorfismo. A idade modelo de Nd (≈ 2,37 Ga) e os dados de U-Pb e litogeoquímicos balizam a hipótese do conjunto cálcioalcalino de médio-K representar rochas de um arco magmático juvenil. A análise isotópica em conjunto com a litogeoquímica sugere que a série toleítica do CJF da região estudada foi gerada em ambiente de fundo oceânico, sendo diferenciada a partir de uma fonte depletada com alguma contribuição de uma fonte enriquecida. / The Juiz de Fora Complex (JFC) in the region of Três Rios (Rio de Janeiro) is appointed by an ample variety composicional, having from granites, tonalite to rocks of composition basic. Through the lithogeochemistry it was possible to subdivide this unity in 4 associations: (i) calc-alkaline of high-K, (ii) calc-alkaline of medium-K, (iii) tholeiitic and (iv) alkaline. By the geochronological analysis(LA-ICPMS, U-Pb) was obtained the age of 2,1Ga for the calc-alkaline group of medium-K, two ages neoproterozoic (615.9 6.4 Ma and 589.1 5 Ma) were dated in an orthogranulite of the toleítico group, what they were interpreted like ages of metamorphism. The model age of Nd (≈ 2,37 Ga) and the data of U-Pb and lithogeochemical mark the hypothesis of the calc-alkaline group of middle-K represents rocks of a youthful magmatic arc. The isotópica together with the lithogeochemistry analysis suggests that the toleítica group of the CJF of the studied region were produced in environment of ocean extensional, being differentiated from a fountain depletada with some contribution of a rich fountain.

Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O Complexo Juiz de Fora (CJF) na região de Três Rios (RJ) é constituído por uma ampla variedade composicional, tendo desde granitos, tonalitos a rochas de composição gabróica. Através da litogeoquímica pôde-se subdividir essa unidade em 4 conjuntos: (i) cálcioalcalino de alto-K, (ii) cálcioalcalino de médio-K, (iii) toleítico e (iv) alcalino. Pela análise geocronológica (LA-ICPMS, U-Pb) foi obtida a idade de 2,1Ga para o conjunto cácioalcalino de médio-K, duas idades neoproterozóicas (615.9 6.4 Ma e 589.1 5 Ma) foram datadas em um ortogranulito do conjunto toleítico, que foram interpretadas como sendo idades de metamorfismo. A idade modelo de Nd (≈ 2,37 Ga) e os dados de U-Pb e litogeoquímicos balizam a hipótese do conjunto cálcioalcalino de médio-K representar rochas de um arco magmático juvenil. A análise isotópica em conjunto com a litogeoquímica sugere que a série toleítica do CJF da região estudada foi gerada em ambiente de fundo oceânico, sendo diferenciada a partir de uma fonte depletada com alguma contribuição de uma fonte enriquecida. / The Juiz de Fora Complex (JFC) in the region of Três Rios (Rio de Janeiro) is appointed by an ample variety composicional, having from granites, tonalite to rocks of composition basic. Through the lithogeochemistry it was possible to subdivide this unity in 4 associations: (i) calc-alkaline of high-K, (ii) calc-alkaline of medium-K, (iii) tholeiitic and (iv) alkaline. By the geochronological analysis(LA-ICPMS, U-Pb) was obtained the age of 2,1Ga for the calc-alkaline group of medium-K, two ages neoproterozoic (615.9 6.4 Ma and 589.1 5 Ma) were dated in an orthogranulite of the toleítico group, what they were interpreted like ages of metamorphism. The model age of Nd (≈ 2,37 Ga) and the data of U-Pb and lithogeochemical mark the hypothesis of the calc-alkaline group of middle-K represents rocks of a youthful magmatic arc. The isotópica together with the lithogeochemistry analysis suggests that the toleítica group of the CJF of the studied region were produced in environment of ocean extensional, being differentiated from a fountain depletada with some contribution of a rich fountain.

Les métaux nobles (Au, Ag, Pt, Ir, Pd et Ru) sont utilisés en salle blanche pour la réalisation de dispositifs électroniques ou peuvent être apportés par les équipements de fabrication (composants d’alliage par exemple). Il a été montré qu’ils pouvaient impacter fortement les dispositifs. Il est alors nécessaire de procéder au contrôle des équipements pour diagnostiquer au plus tôt une contamination. Or, il n’existe pas de technique industrielle pour leur suivi et ce à des niveaux d’au moins 5.109 at.cm-2 - recommandation ITRS. Il se pose la question de la pertinence de ces recommandations en fonction des types de dispositifs (SPAD notamment). Dans un premier temps, les travaux ont consisté à développer une technique physico-chimique pour l’analyse des métaux nobles sur silicium par VPD-DC-ICPMS. Enfin, leur dangerosité vis-à-vis des équipements et des dispositifs a été évaluée d’après leur comportement en température et le DCR généré sur SPAD. / Noble metals (Au, Ag, Pt, Ir, Pd and Ru) are used for the fabrication of microelectronics devices or can be brought by manufacturing tools (alloy components for example). It is well known that these impurities are detrimental to the efficiency of the devices. This implies a real and present need for control of their introduction in clean rooms to diagnose as soon as possible a contamination. Yet, there are no industrial technique for their follow-up at levels about 5.109 at.cm-2 - ITRS recommendations. The relevance of these recommendations according to the electronic device (SPAD in particular) could be questioned. At first, this study consisted in developing a physicochemical technique for the analysis of noble metals on Si wafers by VPD-DC-ICPMS. Then, their dangerousness towards tools and devices was established according to their behavior in temperature and the DCR generated on SPAD devices.

Le but de la présente étude était de vérifier l'influence de deux compartiments du latex d'Hevea brasiliensis, les lutoïdes et le sérum C, sur le durcissement au stockage et sur la mésostructure du caoutchouc naturel (NR). L'implication des composants minéraux du latex a fait l'objet d'un focus spécial. La mésostructure du NR a été étudié par fractionnement par couplage flux-force à flux asymétrique couplé à un détecteur à diffusion de lumière multiangulaire (AF4-MALS) et par chromatographie d'exclusion de tailles équipée d'un détecteur de diffusion de lumière multiangulaire (SEC- MALS). La spectrométrie de masse couplée à une torche à plasma (ICP- MS) a été utilisée pour déterminer la composition en éléments minéraux du NR.L'AF4 - MALS et l'ICP-MS n'ayant jamais été utilisées pour l'analyse du NR, les méthodes ont été développées. Pour l'AF4 - MALS, la meilleure séparation entre les deux populations principales, chaînes de polyisoprène isolées (pelote statistique) et les microagrégats (Gel<1μ), a été obtenue avec une diminution linéaire, plutôt qu'exponentielle, du flux croisé. Pour l'ICP-MS, les optimisations réalisées concernent la quantité de NR à échantillonner, la méthodologie de solubilisation des cendres, la concentration des solutions de cendres et la gestion des interférences m/z . Tous les éléments, excepté le soufre, ont été analysés en utilisant un mélange H2/He comme gaz de collision-réaction (mode CCT H2/He). La teneur en soufre a été déterminée par le rapport m/z égal à 48 (32S16O+) en mode CCT O2.Les différents compartiments du latex des champs (crème, skim, sérum C et lutoïdes) ont été séparés par centrifugation à grande vitesse. L'évolution de la mésostructure des films obtenus à partir de ces trois latex; latex des champ (FL), le latex de crème (CL) et de latex de skim (SK), par un procédé de structuration lente (échantillons stockés à température ambiante dans le laboratoire pendant 3 mois) a été suivie par SEC- MALS. Le skim n'étant pas sensible au processus de structuration lente, le nombre des étapes de centrifugation a été réduit. La stabilité des lutoïdes a été étudiée par un paramètre qualitatif (état visuel des lutoïdes après centrifugation) et un paramètre quantitatif (indice d'éclatement ou BI). Bien que les deux méthodes n'aient pas donné de résultats strictement corrélées, le BI peut être un bon indicateur de la stabilité des lutoïdes. Pour les échantillons de FL, une bonne corrélation entre la stabilité des lutoïdes et le durcissement au stockage (P) a été observée. Pour déterminer si des composés du C-sérum étaient également impliqués dans le durcissement au stockage, des expériences supplémentaires ont été effectuées en ajoutant des quantités variables de sérum C ou de lutoïdes à des particules de caoutchouc purifiées. L'augmentation à la fois de les quantités de sérum C et des lutoïdes a entrainé une augmentation du durcissement au stockage (P).La mésostructure des films et des feuilles séchées de l'air (ADS) préparés à partir des FL et CL a été analysée par SEC-MALS et AF4-MALS. Pour les échantillons d'ADS, quelle que soit la technique utilisée, les échantillons de FL présentaient des Mw, Mn et Gel>1μ supérieurs aux échantillons de CL. Cette différence entre échantillons de FL et de CL n'a pas été observée pour les échantillons de films. / The aim of the present work was to study the influence of two Hevea brasiliensis latex compartments, namely lutoids and C-serum, on the storage hardening and on mesostructure of natural rubber (NR). A special focus was done on the involvement of mineral components of latex. The NR mesostructure was studied by asymmetrical flow field-flow fractionation coupled to a multiangular light scattering detector (AF4-MALS) and by size exclusion chromatography equipped with a multiangular light scattering detector (SEC-MALS). Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the mineral element composition of NR.As AF4-MALS and ICP-MS were never used for NR analysis, the methodologies were developed. For AF4-MALS, the best separation between the two main populations, namely isolated polyisoprene chains (random coil) and microaggregates (Gel<1µ) was given by a linear decrease, rather than exponential, of the cross-flow. For ICP-MS, the optimizations were in terms of amount of NR to be sampled, ash solubilisation methodology, ash solutions concentrations and m/z interference management. All elements, except sulfur, were determined using a mixture H2/He as collision-reaction gas (CCT H2/He mode). Sulfur content was determined through the m/z equal to 48 (32S16O+) in the CCT O2 mode.The different compartments of the whole field latex (cream, skim, C-serum and lutoids) were separated by high speed centrifugation. The mesostructure evolution of films obtained from these 3 lattices; whole field latex (FL), cream latex (CL), and skim latex (SK), by a slow structuring process (samples stored at room temperature in the laboratory for 3 months) was followed by SEC-MALS. As it was observed that the skim was not sensitive to the slow structuring, the centrifugation steps were reduced.Lutoid stability was studied by a qualitative parameter (visual lutoid status after centrifugation) and a quantitative parameter (bursting index or BI). Although the two methods could not provide strictly correlated results, BI can be a good indicator of lutoid stability. For the FL samples, a good correlation between the lutoid stability and storage hardening (ΔP) was observed. To determine if some compounds of C-serum are also involved in the storage hardening, additional experiments were done adding variable quantities of C-serum or lutoids to purified rubber particles. The storage hardening (ΔP) increased by the increase of both C-serum and lutoid quantities.The mesostructure of films and air dried sheet (ADS) made from FL and CL lattices (obtained from reduced centrifugation process) were analyzed by SEC-MALS and AF4-MALS. Concerning the ADS samples, whatever the technique used, FL samples exhibited a higher Mw, Mn, and Gel>1µ than CL samples. This difference between FL and CL samples was not observed for film samples. The microaggregates (Gel<1µ) were presented in all samples but the FL samples had more compact microaggregates, with a much higher Mw than the CL samples. Moreover, AF4 showed that the structure of microaggregates was very different between ADS and film samples. The Mw of microaggregates of ADS was 2 to 4 times higher than that of films. The mineral elements were determined only on samples from ADS (FL and CL). The main elements in NR were K, P, Mg, and S, in decreasing order. The purification of rubber particles affected the decrease in the element contents. During the storage of the latex at room temperature, only calcium content decreased, for both FL and CL samples.

Evaluating the ability of biosorbents to remove arsenic from water has global significance due to the widespread availability and low cost of biosorbent materials. In this study, the ability of coffee grounds and coconut substrate (two previously unreported biosorbents) to remove arsenic from water was compared against the performance of arsenic removal on rice husk (a recognized and widely tested biosorbent). The three biosorbents were individually screened for their ability to remove arsenite, As (III), and arsenate, As (V), from water. Batch reactors were employed to assess the percent removal, reaction kinetics, adsorption capacity, and desorption of each arsenic species onto/from biosorbents under pH buffered and non‐buffered conditions. The resulting experimental data was statistically interpreted using analysis of variance and ttesting of the means. The experimental results were also fit to existing kinetic and isotherm models to provide kinetic rate constants, the maximum adsorption capacity, and to help interpret the nature of the reactions on the biosorbent surface. While all three biosorbents removed arsenic with similar initial reaction kinetics (pseudo 1st order reaction rate constant for As (III) was 0.13 hr^‐1 for all three biosorbents and for As (V) was 0.17 hr^‐1 for coffee grounds and rice husk and 0.15 hr^‐1 for coconut substrate), the amount of arsenite and arsenate removed was highest for coffee grounds (84 and 91 percent, respectively), followed by rice husk (68 and 72 percent, respectively), and then coconut substrate (26 and 24 percent, respectively). The maximum adsorption capacity of arsenite and arsenate was determined for coffee grounds (0.66 and 0.70 mg/g, respectively) and rice husk (0.55 and 0.66 mg/g, respectively). While desorption was observed for both coffee grounds and rice husk, the total amount of desorption accounted for less than 15 percent of the total retained mass. The results of this thesis work reveal that coffee can be used as an effective biosorbent when compared to rice husk; however, coconut substrate is less effective than rice husk at removing As (III) and As (V).

Novel techniques for in-situ lead isotope analysis of melt inclusions using multicollector inductively coupled plasma mass spectrometry, and parallel Faraday cup and ion counter detection have been developed. These provide for measurement of the critical 204Pb isotope, which has been unavailable in melt inclusion Pb isotope studies, but requires on-line determination of 200Hg to correct for 204Hg isobaric interferences. External standardisation allows for effective mass fractionation correction and ion counter gain calibration. An off-line Tau correction was applied and standard glass analyses suggest that this correction provides more accurate and precise results.

The purposes of this study were to characterize the complexation of toxic metals with algal toxins and to determine the effects of arsenic and copper on the growth of Karenia brevis under specific experimental conditions. Microcystins, pahayokolides, brevetoxins and okadaic acid were used as representatives of algal toxins while arsenic, copper, cadmium, cobalt, iron, manganese and mercury were selected as typical toxic metals (including metalloids here) in the aquatic environment. The stabilities of the toxin-metal complexes were determined using equilibrium dialysis and/or centrifugal ultrafiltration technique. A direct exposure of arsenic and copper to the K. brevis was carried out to determine the effects of these metals to the growth of the algal cell. The results indicated that Cu2+, Hg2+, Co2+, Cd2+ and Fe2+ were capable of complexing with the algal toxins. Moreover, the exposure experiments demonstrated that the high concentration of arsenic and copper could affect the growth of the K. brevis.