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Publications (101)
Gadolinium anomalies have become a well-established marker for the pollution caused by wastewater, but there is not yet a standardized method to estimate the anomaly. Here, we compare four different published equations, distinct threshold values and reference normalizing values to estimate Gd anomalies by applying them to the results of a hydrochem...
The use of environmental tracers brings comprehensive benefits to the management of water resources since it helps to prevent their pollution, minimize public health risks, and thus reduce the impact of urbanization. In Brazil, the Guarani Aquifer System (GAS) has strategic and environmental importance, making its preservation and sustainable explo...
Anthropogenic gadolinium (Gdanth) is a frequent contaminant in surface water that receives wastewater treatment (WWT) effluents due to the high stability of Gd-based contrast agents (Gd-CAs) used in magnetic resonance imaging (MRI) exams and excreted by patients. This study describes the presence of Gdanth in surface water of a small drainage area...
We deployed a procedure to measure Li isotope ratios on a single‐collector sector field inductively coupled plasma mass spectrometer (ICP‐SFMS) operated with a desolvation system and a high sensitivity skimmer cone. Under optimised instrumental acquisition conditions, chromatographically separated analyte solutions containing one ng g‐1 of Li provi...
Increasing land transformation in the Amazon basin, from forest to post-forest usage such as pastureland, agriculture and agroforestry, triggers significant changes in hydrology, soil fertility and regional climatology. However, relatively little is known about Amazon basin soil chemistry in general and about possible alteration with recent land-us...
The rivers that comprise the Atibaia and Jaguari medium size subbasins and their interconnected reservoirs (Cantareira Water System) provide drinking water for about one-third of São Paulo's State population. Native vegetation covers nearly 30% of the catchments' territory, and the remaining comprises small-scale farming, reforestation, industries,...
In this study, we investigated the mineral and geochemical compositions of the main lithotypes constituting the Atibaia and Jaguari rivers’ subbasins (Southeast Brazil), with the aims of characterizing the distribution of rare earth elements (REE) in that diversified geological framework and identifying their source bearing minerals to the environm...
The complete dissolution of representative test‐portions of powdered rock samples for the determination of the mass fractions of trace elements by ICP‐MS relies either on aggressive and time‐consuming acid digestions or fusion/sintering with appropriate fluxes. Here we evaluate a microwave oven dissolution method that employs a solution of NH4HF2 a...
Assessment of soil and groundwater contamination by potentially toxic and alloy elements in an impounded vehicle scrapyard
The composition of groundwater primarily reflects hosting lithologies, and according to other studies, natural bottled water can be used as a simple means of groundwater sampling. This study aims to establish compositional relations between the groundwater of six aquifers of São Paulo state, Brazil and host igneous, metamorphic and sedimentary sili...
In Brazil impounded vehicle scrapyards (IVS) are often overcrowded and may pose a source of potentially toxic elements (PTEs). In this study, PTEs content in soil cores and groundwater of an IVS located at a municipality of the São Paulo metropolitan region was assessed. INAA, XRF and ICP-MS were the analytical techniques employed. PTEs results and...
This GGR biennial critical review covers developments and innovations in key analytical methods published since January 2014, relevant to the chemical, isotopic and crystallographic characterisation of geological and environmental materials. In nine selected analytical fields, publications considered to be of wide significance are summarised, backg...
Rare Earth Elements plus Y (REY) data obtained for carbonate rocks of the Bambuí Group in the southern portion of the São Francisco basin match the C and Sr isotope variations that subdivide the unit in three Chemostratigraphic Intervals (CI-1 to CI-3). The lower CI-1 samples exhibit flat REY shale normalised distributions that record a high freshw...
A composição química das águas subterrâneas depende de processos hidrogeológicos, geoquímicos e biológicos, dos quais a interação água-rocha é o mais determinante. Águas minerais envasadas são essencialmente águas subterrâneas e, em princípio, constituem amostras destas. A análise físico-química e composicional de cinquenta e cinco amostras de água...
The impact of a scrapyard of impounded vehicles in São Paulo state on topsoil was evaluated for As, Ba, Co, Cr, Cu, Mo, Ni, Pb, V, Zn and rare earth elements (REEs). Mass fractions of all elements, except for Co, Cu, Mo and Zn, were higher than reference values. Hot spots were observed for most elements suggesting vehicular source. The geoaccumulat...
The concentrations of rare earth elements (REE), measured in water samples from Atibaia River and its tributary Anhumas Creek, Brazil, present excess of dissolved gadolinium. Such anthropogenic anomalies of Gd in water, already described in other parts of the world, result from the use of stable and soluble Gd chelates as contrast agents in magneti...
We present new reference values for nineteen USGS, GSJ, and GIT-IWG rock reference materials that belong to the most accessed samples of the GeoReM database. The determination of the reference values and their uncertainties at the 95% confidence level follows as closely as possible ISO guidelines and the Certification Protocol of the International...
A composição química de águas subterrâneas resulta, em parte, de reações água-rocha nos respectivos aquíferos. Dentre os vários constituintes das águas, os elementos terras raras (ETR) e urânio podem ser traçadores de processos geoquímicos e de fluxos hidrológicos. O principal objetivo deste trabalho foi procurar associações entre as assinaturas qu...
This study presents an evaluation of the quartz sand occurrences of the Santa Maria Eterna formation, in northeastern Brazil, as a potential source of raw material for silica glass manufacturing. Samples of quartz sand were analyzed by ICP-MS to determine a range of trace elements and establish its chemical purity. The technological potential of th...
This work aimed at analyzing quartz lumps rejected from a major metallurgical grade silicon producer and at studying the effect of several processing techniques over its purification. The final objective was to enable the use this lumps as raw material for silica glass production. Chemical analyses using ICP-MS technique were conducted to understan...
Iron formations (IFs) typically contain low mass fractions of most trace elements, including the rare earth elements (REE), and few publications describe analytical methods dedicated to this matrix. In this study, we used bomb and table-top acid dissolution procedures and ICP-MS to determine the mass fractions of trace elements in IF reference mate...
A incerteza da medição expressa a exatidão de um resultado analítico. Uma forma prática de estimar a incerteza de medição é utilizar séries de resultados obtidos ou pela análise de materiais de referência certificados (MRC) ou da participação em testes de proficiência. As duas abordagens foram utilizadas para estimar as incertezas associadas à dete...
In all fields of geochemistry, cosmochemistry, and environmental research, reference materials play an important role. They are used as samples for calibration of analytical instruments and to establish metrological traceability to measurements, quality control and assurance, and interlaboratory comparisons. The International Organization for Stand...
Rare earth elements (REE) are of great geological, technological, economic and strategic interest. The increasing use of REE in high-tech products and the restrictive politics of some countries for commercialization of some REE raw minerals resulted in search for new deposits of these elements as well as the feasibility of unexplored reserves. One...
Rare earth elements (REE) are of great geological, technological, economic and strategic interest. The increasing use of REE in high-tech products and the restrictive politics of some countries for commercialization of some REE raw products resulted in search for new deposits of these elements as well as the feasibility of unexplored reserves. One...
Isotope dilution (ID) mass spectrometry is a primary method of analysis suited for the accurate and precise measurement of several trace elements in geological matrices. Here we present mass fractions and respective uncertainties for Cr, Cu, Ni, Sn, Sr and Zn in 10 silicate rock reference materials (BCR‐2, BRP‐1, BIR‐1, OU‐6, GSP‐2, GSR‐1, AGV‐1, R...
Advances in the chemical and isotopic characterisation of geological and environmental materials can often be ascribed to technological improvements in analytical hardware. Equally, the creation of novel methods of data acquisition and interpretation, including access to better reference materials, can also be crucial components enabling important...
The worldwide increasing demand for renewable energy sources has driven a significant raise in the production of photovoltaic solar cells. In order to manufacture such devices it is required high purity silicon material, which can only be processed using special tools made of high purity silica glass to avoid contamination of the final material. Th...
Sample digestion is a critical stage in the process of chemical analysis of geological materials by ICP-MS. We present a new HF/HNO3 procedure to dissolve silicate rock samples using a high pressure asher system. The formation of insoluble AlF3 was the major obstacle in achieving full recoveries. This was overcome by setting an appropriate digestio...
We present new reference values for the NIST SRM 610–617 glasses following ISO guidelines and the International Association of Geoanalysts’ protocol. Uncertainties at the 95% confidence level (CL) have been determined for bulk- and micro-analytical purposes. In contrast to former compilation procedures, this approach delivers data that consider pre...
The vertical distribution of mercury along a weathering profile derived from a diabase was compared to the main geochemical
and mineralogical characteristics of the soil and its parental rock. The sampling site was in a metropolitan area, nearby
to an active quarry and relatively close to an industrial park. The samples of a 6-m-deep fresh exposure...
The measurement of gaseous mercury in soils over a deep (~90 m) zinc sulfide mineralization was used to evaluate its potential as a mineral exploration technique. The Zn-Pb Santa Maria deposit (Camaquã Basin, RS, Brazil) contains sphalerite and galena as main ore minerals and up to 7 μg/g Hg. Holes at depths of 30 cm and 50 cm were made at preselec...
This collection of articles represents the fourth in a series of reviews in which authors have aimed at capturing the key advances in a range of analytical fields (Hergt et al. 2005, 2006, 2008). The publication period under review is 2008–2009 and the intention here is to provide readers with a summary of the most influential developments publishe...
This review gives an overview of the literature on reference materials of geochemical and environmental interest for the two-year period 2008–2009. Reference materials play an increasingly important role in all fields of geoanalytical research. This is demonstrated by the large number of publications containing data on reference materials. Although...
Inductively coupled plasma mass spectrometry (ICP-MS) is the best fitted analytical technique for multi-element analysis of waters, because of its low detection limits. One limitation is the polyatomic interferences produced in the plasma and in the interface (e.g., 35Cl16O+ on 51V+, 40Ar16O+ on 56Fe+, 40Ar35Cl+ on 75As+ and 40Ar38Ar+ on 78Se+). Th...
There has been little research on metal concentration levels in urban soils of São Paulo, a city with 19 million inhabitants
with severe pollution problems. In the present study, the concentration of As, Ba, Cr, Cu, Pb, Sb and Zn, were determined
by INAA and XRF in surface soil samples from 7 public parks located within São Paulo city. The results...
There has been little research on metal concentration levels in urban soils of São Paulo, a city with 19 million inhabitants with severe pollution problems. In the present study, the concentration of As, Ba, Cr, Cu, Pb, Sb and Zn, were determined by INAA and XRF in surface soil samples from 7 public parks located within São Paulo city. The results...
The immobilization of lead by the reaction with phosphate bearing materials is a promising remediation method for contaminated
soils. Low soluble neo-formed lead-phosphate phases similar to chloropyromorphite [Pb5(PO4)3Cl], can control availability and mobility of lead in the environment, and consequently reduce human exposure, if soils are
the mai...
Reference materials (RM) are essential to achieve traceability of measurements. Specific uses of RM in analytical laboratories are the validation of methods, the calibration of instruments, the quality control and the demonstration of proficiency. This paper describes the certification of a new geochemical reference material, named BRP-1 (Basalt Ri...
In this paper we describe a flux-free fusion technique for the highly precise LA-ICP-MS bulk analysis of geological samples. For this purpose we have developed an automated iridium-strip heater with temperature and melt time control. To optimise the homogeneity of the fused glasses and to reduce possible depletion of volatile elements during meltin...
Incidental ingestion of contaminated soils is a major route of Pb uptake by humans, especially by children. Lead speciation in soils controls its bioavailability. Bioavailability assessment requires the determination of the amount of absorbed lead if a contaminated soil is ingested. In vivo tests, which employ animals, are considered the best model...
Reference materials (RM) are required for quantitative analyses and their successful use is associated with the degree of homogeneity, and the traceability and confidence limits of the values established by characterisation. During the production of a RM, the chemical characterisation can only commence after it has been demonstrated that the materi...
We determined the amount of bioaccessible lead in samples of contaminated soils and in mining and refining wastes collected in the surroundings of a former smelter in a rural area in southeastern Brazil. Previous studies showed that some resident children and adults had blood Pb levels above recommended limits, but the contamination route was not e...
Wavelength dispersive X-ray fluorescence spectrometry (WD-XRF) is widely used for the analysis of soils and sediments using well characterised procedures. However, difficulties can occur with samples such as unknowns containing small amounts of ore materials and samples collected from contaminated sites where trace elemental concentrations can exce...
Inductively coupled plasma-mass spectrometry (ICP-MS) after NiS fire assay-Te co-precipitation was employed in the determination of Ru, Rh, Pd, Os, Ir and Pt at ng g-1 levels in six platinum-group element (PGE) geological reference materials. In general, the average of several results was in good agreement with the certified values taking into acco...
The direct analysis of nickel sulfide fire assay buttons by UV laser ablation ICP-MS was used to determine the platinum-group elements and gold in the following reference materials: UMT-1, WPR-1, WMG-1, GPt-4, GPt-6 and CHR-Bkg. The instrument was calibrated with buttons prepared using quartz doped with the appropriate standard solutions. Analytica...
this study, we used the modified Horwitz expression (H-c = 0.01c(0.8495), which gives the precision as a function of concentration) to evaluate and control the accuracy of results of silicate rock analysis obtained by X-ray fluorescence spectrometry. This expression is currently used by the organisers of the GeoPT international proficiency tests, t...
To get a well-characterized Brazilian basaltic reference material Cotta et al. (2007) prepared BRP-1, which was collected from the Cretaceous Parana Province. About 150 kg of the raw material was crushed and pulverized at the USGS in Denver, USA. Finally, the powder was split into 1920 glass bottles containing about 55 g of material. Homogeneity te...
In the present work, we investigate the iron oxides and oxyhydroxides behavior and evolution, related to the geochemical behavior
of some metals, which could be retained as solid phases in the sediments from an urban water reservoir lake, placed in Taiaçupeba,
Great São Paulo, Brazil. These tasks were performed by the establishment of a proceduring...
In the last years urban soils received increasing attention by scientists, leading to studies focused on their description and investigation all over the world, due to the increasing metal pollution derived from incinerators, industrial waste, atmospheric deposition of dust and aerosols, and other activities. Metal contamination in São Paulo public...
The analytical determination of palladium derived from car emissions and deposited on topsoil has close resemblance to the determination of palladium in geological samples in general. On Earths crust Pd occurs associated with other precious metals (Pt, Rh, Ir, Ru and Os, which are collectively known as platinum group elements, PGE). Their abundance...
The distribution of platinum, palladium, and rhodium in soils adjacent to a major road in São Paulo, Brazil, is presented. Sampling was made at four sites with varying traffic volumes and driving styles (stop/start vs. constant speed). High-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) with NiS fire assay collection and Te cop...
Forest burning for pasture installation in tropical areas represents an important component on biogeochemical cycles. In order to get information about modifications within the element composition after forest burning, in this local study the attempt has been undertaken to provide a first overview about the total contents of a larger set of element...
The application of sewage sludge on soils is a common practice, but the
heavy metals should be determined before disposal. Sewage sludges
composition is mainly organic and the amount of heavy metals is
variable. Usual methods for heavy metals determination are based on
dissolution of the sample. The results depend, partially, on the
efficiency of t...
Goethite (α-FeOOH) is abundant at the Earth's surface and has the unusual capacity to adsorb and fix ions from migrating solutions. Understanding the mechanisms by which foreign elements are incorporated into natural goethite has implications for environmental and mining problems. X-ray absorption spectroscopy (XAS) was used to obtain structural in...
Scolecite is a zeolite associated to basalts of the Parana Continental Igneous Province (PCIP South America). The potential of scolecite as a new material for heavy metal removal (Pb2+ Cu2+, Zn2+, Ni2+, Co2+ and Cd2+) from aqueous solutions is evaluated. The experiments were carried out by immersion of 0.5 g of sample in solutions containing the me...
A set of goethite samples from the oxidized level of Vermelho Ni-lateritic deposit was investigated by TEM, XRD, TGA-DTA, FTIR and Mssbauer spectroscopy and compared to a series of synthetic goethite samples, with similar Ni content. Natural Ni-containing goethite presents poor crystallinity and does not incorporate more than about 4 mol% Ni. Natur...
Forest burning for pastures in tropical areas represents an important component of biogeochemical cycles. In order to provide information concerning chemical modifications after forest burning, in this local study the total contents of 29 elements in topsoils were analyzed when forest is changed to pasture land. The work was carried out in 1999 in...
Soil and sediment reference materials were used to calibrate and evaluate an analytical method for the determination of major
(Si, Al, Fe, Mg, Ca, Na, K, Mn, P, Ti) and trace elements (As, Ba, Cd, Co, Cr, Cu, Ga, Mo, Mb, Ni, Pb, Rb, S, Sb, Sn, Sr,
Th, U, V, Y, Zn, Zr) by sequential wavelength X-ray fluorescence spectrometry. Samples were prepared a...
The ‘ochreous laterite’ is the oxidised nickel ore from the Punta Gorda deposit, Cuba. Mössbauer spectroscopy, X-ray diffraction (XRD), thermal methods and selective extraction techniques have been used to characterise the ore. The ore consists mainly of poorly crystalline Al-substituted goethite. The poor crystallinity of goethite is demonstrated...
NAA and UV laser ablation ICP-MS were used to determine platinum group elements (PGEs) and gold in the geological reference materials UMT-1, WPR-1, WMG-1, GPT-4 and GPt-6, after NiS fire assay. Both methods presented results were good agreement with the recommended values. NAA gave more accurate values for Ir (relative errors between 0 to 9%) and U...
The golden-faced saki monkey Pithecia pithecia chrysocephala (Cebidae, Primates) was observed eating soil from termite nests during a long-term study of a family group in a Central Amazonian forest fragment. In this paper we describe the behaviour involved in the geophagy in these monkeys, and the results of geochemical and physical analyses of the...
In this work, a UV laser system coupled to high-resolution ICP-MS was used in the determination of platinum group elements (PGE) and gold in nickel sulfide buttons prepared by the fire assay technique. A Nd: YAG laser operating at 266 inn quadrupled frequency was used. The laser operating parameters were established by studying signal intensity and...
A fusion procedure commonly used for major element analysis of silicate rocks (1:5 sample to flux ratio, using 0.7 g of sample) was used to determine a small group of trace elements (Cu, Zn, Rb, Sr, Y, Zr, Nb) by X-ray fluorescence. Compton scatter peak ratioing was successfully used for matrix corrections, despite the thickness of the glass discs...
A series of experiments was undertaken to measure the recovery efficiency of platinum, palladium and gold from silicate rocks using a sodium peroxide fusion followed by anion exchange separation of the analytes as chloro complexes. Results obtained by graphite furnace atomic absorption spectrometric analysis of standard solutions prepared in dilute...
A method was developed for the determination of Ru, Pd, Ir and Pt in geological samples by isotope dilution inductively coupled plasma mass spectrometry. After fusion of the sample with sodium peroxide, the platinum group elements were preconcentrated by Te coprecipitation. Results obtained for the reference materials WGB-1, TDB-1, UMT-1, WPR-1, WM...
The mutual coagulation of colloidal gold and iron oxides (goethite and hematite) was studied. The behavior of the mixed systems was observed by TEM. In 0.1 M sodium nitrate solution homocoagulation of the gold particles is observed, instead of the heterocoagulation observed in diluted electrolyte solutions. Peptization experiments with the colloida...
Lateritic gold enrichment can be associated with the formation of colloidal gold and its interaction with the iron-oxide-rich medium. Adsorption of colloidal gold on synthetic goethite and hematite was measured at 25°C. The observed high affinity between the oppositely charged particles depends on the medium composition. The presence of citrate ani...
The Precambrian granulite facies terrain of southwestern India is intruded by a suite of alkali granite and syenite plutons. RbSr whole-rock isotope data for the Angadimogar syenite (AM) and the Peralimala alkali granite (PM), belonging to this suite, define isochron ages of 638 ± 28 and 750 ± 40 Ma, respectively, with initial ratios of 0.7032 ± 0...
The presence of elevated metal concentrations in soils of the urban environment has been recognized as an important source of metal intake to humans, particularly to children, which are more susceptible to the adverse effects of soil ingestion than adults. There has been little research on urban soils in São Paulo, a very populated city with severe...
In the present study, the concentration and distribution of Ba, Cu, Mo, Pb, S, Zn and Zr in soils collected along two main avenues (Pinheiros River Highway and Tietê River Highway) with high traffic density in the metropolitan region of São Paulo, Brazil, are presented, and their possible sources are discussed. These elements are strongly considere...