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1.
Chemosphere ; 237: 124448, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31398606

RESUMO

The Mediterranean Sea remains a complex system for mercury (Hg) cycling and accumulation in marine vertebrates. The extremely high levels these animals present demand for an urgent understanding of such processes and the development of new analytical techniques that go beyond the simple contamination monitoring. It was often proposed that prey selection or habitat use may affect Hg contamination in animals; however, it was never possible to measure which factor influences more rates and pathways of contamination. In this paper, we directly integrate toxicological information (Hg levels) and ecological tracers (stable isotopes of C, N and S) into a common data analysis framework (isotopic niches), with the aim of quantifying the influence of species' trophic behaviour on Hg contamination. The analysis was conducted on skin biopsies of fin whales Balaenoptera physalus, long-finned pilot whales Globicephala melas and sperm whales Physeter microcephalus. Their different trophic modes and residency in the area make them model species for the analysis of Hg accumulation along NWMS food webs. We measured Total Hg (T-Hg) concentrations through absorbance spectrometry with the DMA80 Milestone. Carbon, nitrogen and sulphur isotope compositions were measured via mass spectrometry in an IRMS coupled to an Elemental Analyser (EA) Isoprime. Comparison of ecological and contamination niches allowed to explain Hg accumulation in Mediterranean marine predators. Factors such as food web complexity, trophic position, hunting distribution or habitat use (e.g., foraging depth) did not influence Hg exposure. It is rather the selection of prey type, which determines the range of potential Hg sources and as a consequence the rates of accumulation in whales' tissues. A generalist piscivorous species such as the pilot whales will bioaccumulate more Hg than specialised sperm whales feeding mostly on cephalopods.


Assuntos
Ecologia , Monitoramento Ambiental , Cadeia Alimentar , Isótopos/análise , Baleias/metabolismo , Animais , Isótopos de Carbono/análise , Baleia Comum/metabolismo , Mar Mediterrâneo , Isótopos de Mercúrio/análise , Isótopos de Nitrogênio/análise , Cachalote/metabolismo , Isótopos de Enxofre/análise , Poluentes Químicos da Água/análise , Baleias Piloto/metabolismo
2.
Environ Pollut ; 254(Pt B): 113050, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31465906

RESUMO

Anthropogenic Pb emitted from East Asia, particularly China, is often long-range transported to the east by the prevailing westerlies. To characterize the geographical properties of varying atmospheric Pb concentrations by transboundary and domestic source(s)-related Pb in Korea, closely adjacent to China, the Al and Pb concentrations and the stable Pb isotopic composition were determined in the total suspended particles (TSP) collected at urban (IC), rural (TA), and remote background (JJ) sites in western Korea from August 2015 to October 2016. The annual average Pb concentrations were significantly higher in urban and rural areas (IC, 16.2 ng m-3 and TA, 11.1 ng m-3) than in remote area (JJ, 6.41 ng m-3), showing pronounced seasonal variations with relatively higher concentrations in winter and spring and lower concentrations in summer and autumn. Significantly high enrichment factors (EF) for Pb indicate that anthropogenic contributions are important for this toxic element in TSP. Coupling the Pb isotopic signatures with the air mass back trajectories identified the major potential source regions for individual samples. The results show that during winter, China was the dominant contributor, accounting for 92%, 82%, and 100% of the sampling periods at IC, TA, and JJ, respectively. The Chinese contribution decreased in summer and autumn, whereas the Korean contribution increased, according to the East Asian monsoon system. The Pb concentrations increased by 2.2 (IC), 1.2 (TA) and 1.4 (JJ) times when the Chinese contribution was dominant, compared to the Korea-dominant periods. The Pb isotopic systematics for the samples characterized by the dominant Korean contribution differed substantially between the three sites, implying that the relative importance of various domestic sources varied with geographical areas in western Korea.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Chumbo/análise , China , Extremo Oriente , Isótopos/análise , República da Coreia , Estações do Ano
3.
Forensic Sci Int ; 302: 109884, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31377688

RESUMO

Naturally occurring stable isotopes of several elements are important tracers in the study the wildlife ecology including the identification of origins for migration research, investigations of trophic relationships, and in the forensic determination of illegally harvested and captive fauna. Extensive illegal trapping for use as decoys and in cuisine has contributed to drastic declines of Ortolan Bunting Emberiza hortulana populations breeding and migrating through France. We contrasted feather hydrogen isotope (δ2Hf) values in illegally captured and subsequently confiscated Ortolan Buntings (n=234), including feathers known to have grown in captivity (n=34) or of unknown growing environment (wild or cage), with δ2Hf values in birds legally caught (ringed and released) in the wild (n=40). We sought to determine if feathers from these bird groups could be differentiated based on this single isotope. Feathers grown in captivity had considerably lower δ2Hf relative to feathers of wild birds, which is potentially indicative of tap water consumption and the use of different diets in captive birds. Further, applying mixing models to δ2Hf values revealed similar proportions of captive vs. wild origins for birds illegally captured in 2012, 2014 and 2015, and a larger proportion of individuals with feathers grown in the wild in 2013. This potentially mirrors the confiscation of birds at poaching sites only in the former years, but also of recently caught wild buntings kept captive in 2013. Our results show that even a single stable isotope (δ2H) with good association with origins where feather keratins are produced is potentially useful in understanding origins of captive birds and may advance the monitoring of illegally captured birds.


Assuntos
Crime , Plumas/química , Hidrogênio/análise , Isótopos/análise , Aves Canoras , Animais , Animais Selvagens , Biomarcadores/análise , Conservação dos Recursos Naturais/legislação & jurisprudência , França , Humanos
5.
Arch Environ Contam Toxicol ; 77(3): 377-389, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31312864

RESUMO

Patterns of lead and other trace metals were examined in 122 Eurasian eagle owls Bubo bubo found dead in Sweden in the period 1978-2013. Environmental lead (Pb) has decreased over recent decades from reduced anthropogenic emissions but mortality by Pb poisoning is still frequently reported for avian raptors and scavengers exposed to Pb ammunition. One objective here was to determine if Pb concentrations in a nocturnal non-scavenging raptor follow the general decline observed in other biota. Pb concentration in owl liver was significantly correlated with body weight, sex, latitude, longitude and season. Pb showed a significant decreasing trend towards north and west. Starved birds had significantly higher concentrations. Total Pb concentrations in liver averaged 0.179 µg g-1 dry weight (median 0.103) and decreased by 5.6% per year 1978-2013, or 5.3% after adjustment for confounding factors, similar to trends in other species. Among 14 other trace elements only antimony and arsenic showed decreasing trends. Lead isotope ratios 206Pb/207Pb and 208Pb/207Pb increased from 1.138 and 2.408 in 1978-1985 to 1.170 and 2.435 in 2010-2013, respectively, demonstrating that the decreasing Pb concentration in eagle owl is related to the phase-out of leaded gasoline in Europe, where Pb additives had much lower isotope ratios than natural lead in Swedish soils. Only one incidence of suspected Pb poisoning (40.7 µg g-1 in liver) was observed indicating that poisoning from ingestion of metallic lead is rare (< 1%) in eagle owl in Sweden, in contrast to what has been reported for eagles.


Assuntos
Poluentes Ambientais/análise , Metais/análise , Estrigiformes , Animais , Monitoramento Ambiental/métodos , Feminino , Isótopos/análise , Chumbo/análise , Intoxicação por Chumbo/veterinária , Fígado/química , Masculino , Suécia , Oligoelementos/análise
6.
Chemosphere ; 236: 124305, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31306975

RESUMO

Attempt has been made to discriminate groundwater salinity causes along the east coast of India. A total of 122 groundwater samples (61/season) were collected for two diverse seasons (Pre Monsoon and Post Monsoon) and analyzed for physical and chemical components along with stable isotopes. The Piper diagram proposes samples along the coast predisposed by saltwater incursion. Ionic ratio plots recommend groundwater discriminatory by changing geochemical signatures. The statistical correlation suggests impact of saltwater incursion, anthropogenic and rock water interaction as sources for dissolved constituents in groundwater. The thermodynamic stability plot suggests higher silicate dissolution, weathering and ion exchange prompting water chemistry nevertheless of seasons. The δ18O and δ2H increases towards the sea suggesting enrichment attributed to the sea water influence and rainfall influences along the southwestern parts of the study area.


Assuntos
Monitoramento Ambiental/métodos , Água Subterrânea/química , Salinidade , Água do Mar/química , Poluentes Químicos da Água/análise , Índia , Isótopos/análise , Estações do Ano , Termodinâmica
7.
Chemosphere ; 233: 705-710, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31195275

RESUMO

Speciation and isotopic analyses of mercury (Hg) detected at high concentration (11-107 mg total Hg/kg) in the hair samples of Pakistani subjects were carried out to analyze whether the source of Hg was the skin cream or the soap they used. Liquid chromatography-ICP mass spectrometric speciation analysis revealed that the Hg in the hair was primarily inorganic. This result supported our assumption that skin care products were the source of the high concentration of Hg in hair, which was based on the statistical association found in our previous study because it is known that inorganic Hg compounds are added to some skin care products sold in some countries. Stable isotope ratios of the Hg in the hair samples of 6 subjects and 3 skin cream samples, which were reported to be used by the subjects, were measured by multi-collector ICP mass spectrometry after acid digestion. A comparison of the isotopic compositions of Hg in hair and skin cream in two subjects revealed that the composition in both samples matched in one subject, hence confirming that the products were the source of high Hg concentration in hair. However, the isotopic compositions of Hg in hair and skin cream did not match in the other subject demonstrating the presence of other exposure source(s).


Assuntos
Exposição Ambiental/análise , Poluentes Ambientais/análise , Cabelo/química , Mercúrio/análise , Humanos , Isótopos/análise , Espectrometria de Massas/métodos , Paquistão
8.
J Agric Food Chem ; 67(25): 7183-7189, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31150243

RESUMO

As a result of the important roles of boron (B) in the growth of plants, the uptake of B by plants is dependent upon the existing form and content of available B in soil, which can bring about the local cycle of B isotope equilibrium. A method using water-heating extraction combined with three-step ion-exchange chromatography was developed for the extraction and isotopic analysis of available B in soil. The extraction efficiency and fractionation of B isotopic composition in the procedure were investigated. The results showed that, in the upper layers of soils, the change of δ11B values was opposite that of the mass concentration and a similar variation between δ11B and content occurred in the lower layers. The isotope of available B in soil can create a featured isotopic signature to further understand the geochemical details related to the soil properties and molecular mechanism of B uptake in plants.


Assuntos
Boro/análise , Isótopos/análise , Solo/química , Boro/metabolismo , Isótopos/metabolismo , Espectrometria de Massas , Plantas/metabolismo
9.
Mar Pollut Bull ; 144: 216-223, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31179991

RESUMO

Guanabara Bay (southeastern Brazil) is located in the metropolitan region of the Rio de Janeiro State and is being affected by high levels of anthropization. This work analyzes not only the concentrations of potentially toxic elements (PTEs), but also Pb stable isotopes to trace possible anthropogenic and natural sources of pollutants in the northern region of Guanabara Bay and the Suruí and Magé rivers. The Governador Island Channel, the regions to the north of Governador Island, north and west of Paquetá Island, and the Magé coast are most affected by PTEs. In the study area, high PTE concentrations result from both natural and anthropogenic sources. The main sources of metals include municipal solid waste incineration, atmospheric aerosols, and ore lead tailings, as indicated by Pb isotopes. This work shows that Pb stable isotopes, associated with metal contamination, can improve the assessment of estuarine environment quality.


Assuntos
Baías/química , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Chumbo/análise , Metais Pesados/análise , Poluentes Químicos da Água/análise , Brasil , Ilhas , Isótopos/análise , Rios/química
10.
Mar Pollut Bull ; 142: 76-84, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31232351

RESUMO

Stable isotopes and geochemical proxies (TOC/TN and Chla/TOC) in sediments can be used to distinguish organic matter sources (anthropogenic, terrestrial, or marine). This study aims to characterize organic matter (OM) in superficial sediments from three sectors of central Chile (33°S) that are highly influenced by urban and industrial development. Our results show that a substantial fraction of these OM in Quintero Bay is anthropogenic, from industrial and domestic wastewater sources. In contrast, a mixture of terrestrial and anthropogenic OM dominates the isotopic signal of surface sediments from Concón, derived from non-point industrial and agriculture sources associated with the Aconcagua River basin, while Ritoque exhibited a mixture of different OM sources. However, deposition of allochthonous OM in our study area depends on coastal topography, which influences the local currents and well-ventilated waters, promoting the dispersion and assimilation of OM and thus providing an environment with a high capacity for natural remediation.


Assuntos
Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Compostos Orgânicos/análise , Poluentes Químicos da Água/análise , Agricultura , Chile , Isótopos/análise , Poluição Difusa/análise , Compostos Orgânicos/química , Poluentes Químicos da Água/química
11.
Sci Total Environ ; 688: 600-608, 2019 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-31254826

RESUMO

Cadmium production has risen 1000-fold in the past 100 years, from under 20 to over 20,000 tons per year, causing anthropogenically-mobilized Cd to overwhelm natural sources in global cycling. Cadmium has no known biological function in humans, yet has biochemical behaviors similar to zinc and manganese, making exposure detrimental to human health. Identifying and quantifying the sources of Cd for human sub-populations is key to reducing exposures. Cadmium stable isotopes may provide a method for tracing Cd sources throughout the environment and the human body, but at present the limited database for high precision Cd isotopic compositions is inadequate to support such an analysis. Here, we provide new Cd isotope data on dietary sources, cigarette smoking components, and environmentally relevant standard reference materials. Results indicated that minor but significant variations are observed in food products (e.g., peanuts, sunflower seeds, spinach, kale, lettuce, cocoa powder; ~0.9‰ at 4 amu) that may be useful for tracing contamination in agricultural soils. In contrast, Cd isotope fractionation during smoking is larger (~6‰ at 4 amu) and has implications for tracing cadmium sources from tobacco combustion in the environment and throughout the human body. The primary inhaled component of cigarette smoke contains highest delta values (δ116/112Cd or δ114/110Cd ~5.2‰), while the second-hand smoke and cigarette ash have the lowest delta values (δ116/112Cd or δ114/110Cd ~-0.9‰). Used cigarette butts have δ114/110Cd ~2.4‰, in between the values measured in ash/s hand smoke and the inhaled smoke components. The high delta values of the inhaled smoke indicate that Cd isotopes may be used to determine the extent of Cd exposure due to smoking in human biological samples. This study provides new data for previously uncharacterized isotopic reservoirs that can be included in future studies of Cd source-exposure tracing.


Assuntos
Cádmio/análise , Poluentes do Solo/análise , Tabaco/química , Fracionamento Químico , Monitoramento Ambiental , Isótopos/análise , Solo/química , Poluição por Fumaça de Tabaco/análise
12.
Environ Pollut ; 252(Pt B): 1344-1356, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31254892

RESUMO

With developments in multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS), applications of metal stable isotopes received increasing attentions in the studies of source and fate of heavy metals in the environment. In light of the rapid progresses in this emerging field, we attempted to review the recent findings comprehensively in a way that environmental scientists can easily read. This review started with an introduction of basic terminologies in isotope geochemistry, followed with detailed descriptions of instrumentation and analytical procedures, and finally focused on the cases of three typical metal stable isotopes (Ag, Hg and Zn) to illustrate how they were applied to address environmental issues. Additionally, future perspectives on the applicability, opportunities, and limitations of metal stable isotope techniques as novel approaches in advancing environmental chemistry were discussed.


Assuntos
Monitoramento Ambiental/métodos , Espectrometria de Massas/métodos , Mercúrio/análise , Prata/análise , Zinco/análise , Monitoramento Ambiental/instrumentação , Isótopos/análise , Mercúrio/química , Isótopos de Mercúrio/análise , Prata/química , Análise Espectral , Zinco/química
13.
J Chromatogr A ; 1603: 278-287, 2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31208793

RESUMO

Revealing fractionations of chlorine and bromine isotope in electron ionization mass spectrometry (EI-MS) is crucial for accurate compound-specific isotope analysis of chlorine/bromine (CSIA-Cl/Br) for halogenated organic compounds (HOCs) using gas chromatography EI-MS (GC-EI-MS). This study investigated chlorine/bromine isotope fractionation of 12 organochlorines and 5 organobromines in EI-MS using gas chromatography-high resolution mass spectrometry. The observed isotope fractionations were evaluated with relative variation of chlorine/bromine isotope ratios (Δ37Cl or Δ81Br) between precursor ions and their product ions. All the 17 HOCs exhibited significant isotope fractionations with varied modes and magnitudes depending on compound and EI energy. The magnitudes of the observed isotope fractionations were extremely large in contrast to those in in-solution dehalogenation reactions, showing the Δ37Cl and Δ81Br values within the ranges of -149.2 to 292.0‰ and -362.2 to 546.2‰, respectively. Inter-ion and intra-ion isotope fractionations counteractively influenced the measured chlorine/bromine isotope ratios of individual dehalogenation product ions, whereas only the former could affect (enhance) the measured isotope ratios of molecular ions. The magnitudes of inter-ion isotope fractionation were generally lower than those of intra-ion isotope fractionation for most HOCs (11/17). Stable EI energy and isotope-ratio calculation using complete chlorine/bromine isotopologues of individual molecular ions help to obtain CSIA-Cl/Br data with high precision and accuracy. The results of this study could facilitate exploration of chlorine and bromine isotope fractionations of HOCs during dehalogenation in such conditions as photoinduced dehalogenation, and further elucidate relevant dehalogenation pathways in light of reaction mechanisms revealed by CSIA data.


Assuntos
Bromo/química , Fracionamento Químico/métodos , Cloro/química , Elétrons , Cromatografia Gasosa-Espectrometria de Massas/métodos , Hidrocarbonetos Halogenados/química , Íons , Isótopos/análise
14.
Environ Sci Pollut Res Int ; 26(23): 23899-23922, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31222648

RESUMO

The Jialing River is the second largest headwater tributary of the Yangtze River in China, therefore, the river water has been contaminated and water quality is deteriorated. Hence, this study aims to find the main controling factors of riverine chemistry. 52 water samples were collected for the determination of major ions and environmental isotopes of δ18O and δ2H. Stoichiometry of geochemical data with mixing end members and multivariate statistical analysis were employed with integrated GIS approach for data interpretations. The δ18O and δ2H of the Jialing River Basin (JRB) were used to define the origin of river water from meteoric water and water in the spring season is affected by high evaporation and evaporates dissolution. The average TDS 301 mg/L that is higher than the Yangtze River. In the JRB, 80% of the anion in water samples represented HCO3- (207 mg/L) and SO42- (80 mg/L) while 80% of the cations were accounted by Ca2+ (59.8 mg/L) and Mg2+ (17.9 mg/L). The water chemistry mainly derived from the water rock interaction. Piper plot indicated that Ca-Mg-HCO3- was the most dominant water type and most ions derived from carbonate weathering by H2SO4 and H2CO3. The stoichiometry results further confirmed carbonate weathering is dominant than silicate weathering. Evaporate ions were modified by anthropogenic sources. Agricultural inputs are higher than the industry and atmospheric inputs. Redundancy analysis showed that most contributive land-use type in explaining riverine chemistry was the cultivate land (62.6, 66.4, and 67.9%) at all buffer scales of 30, 20, and 10 km, respectively. Forest and grasslands mostly correlate with Ca2+, Mg2+, Cl-, SO42-, EC, pH, and HCO3- while anthropogenic land-use types such as cultivated and construction lands correlate with Na+, K+, Cl-, and NO3-. These results revealed that the lithology of the basin mainly controlled the upstream water chemistry while downstream riverine chemistry was controlled by both lithology and anthropogenic inputs. Nevertheless, this study suggested that explicitly determining the controlling factors of riverine chemistry involves a complex process and combination of different chemical constituents and factors on river water. However, this study managed to provide useful information to further understanding of the geochemical process in JRB.


Assuntos
Carbonatos/análise , Poluentes Químicos da Água/análise , Água/análise , Agricultura , Carbonatos/química , China , Isótopos/análise , Isótopos/química , Rios , Estações do Ano , Água/química , Poluentes Químicos da Água/química , Qualidade da Água , Tempo (Meteorologia)
15.
Sci Justice ; 59(3): 322-331, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31054821

RESUMO

Human provenance studies employing isotopic analysis have become an essential tool in forensic and archaeological sciences, with multi-isotope approaches providing more specific location estimates compared to single isotope studies. This study reports on the human provenancing capability of neodymium isotopes (143Nd/144Nd), a relatively conservative tracer in the environment. Neodymium isotope ratios have only recently been determined on human remains due to low concentrations in human dental enamel (ppb range), requiring thermal ionisation mass spectrometry (TIMS) using 1013â€¯Ω resistors. Dental elements (third molars) from 20 individuals born and raised in the Netherlands were analysed for Nd concentration (n = 12) and Nd isotope ratios (n = 15). The geological control on Nd isotope composition was examined using coupled Nd-Sr isotope analysis of the same third molar. Teeth from different geological environments were also analysed (Caribbean, Columbian, and Icelandic, n = 5). Neodymium elemental concentrations in dental elements ranged between 0.1 and 7.9 ppb (median 0.5 ppb). The Dutch 143Nd/144Nd ratios of the provinces of Limburg and Friesland were between 0.5118 and 0.5121, with Dutch 87Sr/86Sr ratios in agreement with the previously established local range (0.708-0.710). The current findings were compared to previously published results on Nd concentration and composition from Dutch individuals. The concentration of Nd and 143Nd/144Nd ratios were weakly correlated (R2 = 0.47, n = 17) in Dutch human dental enamel. The majority (n = 25, 83.3%) of individuals had Nd and Sr isotope values isotopically indistinguishable from the geological environment in which their third molars formed and mineralised. However, the Nd isotope ratios of the Icelandic individual and several Dutch individuals (n = 4) suggested that Nd in enamel is not solely influenced by geological environment. In order for neodymium isotopes to be quantitatively applied in forensic and archaeological settings further analyses of individuals from various geographical regions with well-defined dietary Nd isotope data are required.


Assuntos
Esmalte Dentário/química , Isótopos/análise , Espectrometria de Massas , Dente Serotino/química , Neodímio/análise , Radioisótopos/análise , Adolescente , Região do Caribe , Criança , Colômbia , Dieta , Impedância Elétrica , Odontologia Legal/métodos , Humanos , Islândia , Países Baixos , Dinâmica Populacional , Isótopos de Estrôncio/análise
16.
Environ Sci Pollut Res Int ; 26(21): 22051-22060, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31144184

RESUMO

The analytical procedure for reference measurements of Hg in marine environmental samples based on cold vapour generation (CVG) inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) and isotope dilution calibration strategy (ID) is described in the present study. The procedure was applied on different matrices and varying mass fractions for mercury in oyster, marine sediment and costal seawater samples. The use of CVG for sample introduction resulted in sensitivity enhancement, reduction of blank levels, minimization of matrix interferences and the elimination of memory effects. The entire measurement process was described by mathematical equations, and all factors influencing the final results were systematically investigated. The expanded uncertainty on results was estimated following the ISO/Guide to the Expression of Uncertainty in Measurement guidelines, and all major contributions were identified. Modelling of the entire measurement process and the use of primary method of measurements ID ICP-MS related obtained values for total mercury in different types of marine matrices to the international system of units SI. Obtained results for mercury mass fractions in biota and marine sediments were used as the International Atomic Energy Agency's  contribution in the certification campaigns for marine reference materials and were in excellent agreement with the assigned reference values.


Assuntos
Monitoramento Ambiental/métodos , Mercúrio/análise , Poluentes Químicos da Água/análise , Animais , Calibragem , Gases , Sedimentos Geológicos/química , Técnicas de Diluição do Indicador , Isótopos/análise , Espectrometria de Massas/métodos , Ostreidae , Valores de Referência , Espectrofotometria Atômica , Análise Espectral
17.
Environ Pollut ; 250: 762-772, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31035159

RESUMO

To differentiate the source of aeolian dust between the desert sources from Pan-third pole and high mountain glaciers, therefore, we investigated the spatial variability of aeolian dust sources in the Pan-third polar region. The question of whether such changes reflect variable transport pathways from a unique source in the western China area was addressed. That is, the SrNd radiogenic isotope composition of modern desert samples do not support the hypothesis of a single dust provenance at higher elevation mountain glaciers by long-distance transport; regional sources also play a significant role. Based on previous studies and the data from this study, the five isotopic regions were divided, which are controlled by the geological characteristics in western China. The results suggest that mineral dust deposited into the high-mountain glaciers originated from the free ice region because of glacier melting and the physical and chemical erosion of rocks from the surrounding mountains by local wind systems. The Pb isotopic data further demonstrated that natural dust is the source of Pb for the high-mountain glaciers of Pan-third pole. These results provide an exhaustive documentation of the isotopic signature of the regional dust reaching the glacier regions.


Assuntos
Altitude , Poeira/análise , Monitoramento Ambiental/métodos , Camada de Gelo/química , Vento , China , Isótopos/análise
18.
Environ Geochem Health ; 41(6): 2443-2458, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31016607

RESUMO

Among the results of community health impact assessments completed in 2014, residents of the Indae abandoned metal mine area showed high average urinary concentrations of harmful arsenic (As), at 148.9 µg/L. The concentration of harmful As was derived as the sum of As(V), As(III), MMA, and DMA concentrations known to be toxic. In this area, mining hazard prevention work was not carried out and the pollution source was neglected, and the health effect of the residents due to arsenic exposure was concerned. We re-assessed As exposure levels and tried to identify exposure factors for residents of this area. Analysis of the soil, sediment, and river water to assess the association between the soil of the Indae abandoned metal mine area and the soil in residential areas confirmed a correlation between Pb and As concentrations in the soil. Since Pb and As behave similarly, the use of the stable Pb isotope ratio for assessment of the pollution source tracking was validated. In the 3-isotope plot (207/206Pb vs. 208/206Pb) of soil samples in this area, a stable Pb isotope ratio was located on the same trend line, which confirmed that the soil in the residential area was within the area of influence of the Indae abandoned metal mine. Therefore, we judged that the pollution source of As was the Indae abandoned metal mine. The results by As species were As (III) 1.45 µg/L, As (V) 0.74 µg/L, monomethylarsonic acid (MMA) 2.43 µg/L, dimethylarsinic acid (DMA) 27.63 µg/L, and arsenobetaine 88.62 µg/L. The urinary harmful As was 31.92 µg/L, much lower than the 148.9 µg/L reported in a 2014 survey, due to the implementation of a multi-regional water supply in November 2014 that restricted As exposure through drinking river water. However, concerns remain over chronic exposure to As because As in river water used for farming and in agricultural soil still exceeds environmental standards; thus, ongoing work to address hazards from former mining areas and continued environmental monitoring is necessary.


Assuntos
Arsênico/análise , Exposição Ambiental/análise , Mineração , Poluentes do Solo/análise , Poluentes Químicos da Água/análise , Adulto , Idoso , Agricultura , Arsênico/urina , Arsenicais/análise , Exposição Ambiental/efeitos adversos , Monitoramento Ambiental , Feminino , Água Doce/análise , Sedimentos Geológicos/análise , Humanos , Isótopos/análise , Chumbo/análise , Masculino , Pessoa de Meia-Idade , República da Coreia , Rios/química , Fatores Socioeconômicos , Inquéritos e Questionários , Abastecimento de Água
19.
J Chromatogr A ; 1599: 66-74, 2019 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-30961962

RESUMO

Cyanobacteria can form dense blooms under specific environmental conditions, and some species produce secondary metabolites known as cyanotoxins, which present significant risks to public health and the environment. Identifying toxins produced by cyanobacteria present in surface water and fish is critical to ensuring high quality food and water for consumption, and protectionn of recreational uses. Current analytical screening methods typically focus on one class of cyanotoxins in a single matrix and rarely include saxitoxin. Thus, a cross-class screening method for microcystins, nodularin, anatoxin-a, cylindrospermopsin, and saxitoxin was developed to examine target analytes in environmental water and fish tissue. This was done, due to the broad range of cyanotoxin physicochemical properties, by pairing two extraction and separation techniques to improve isolation and detection. For the first time a zwitterionic hydrophilic interaction liquid chromatography column was evaluated to separate anatoxin-a, cylindrospermopsin, and saxitoxin, demonstrating greater sensitivity for all three compounds over previous techniques. Further, the method for microcystins, nodularin, anatoxin-a, and cylindrospermopsin were validated using isotopically labeled internal standards, again for the first time, resulting in improved compensation for recovery bias and matrix suppression. Optimized extractions for water and fish tissue can be extended to other congeners in the future. These improved separation and isotope dilution techniques are a launching point for more complex, non-targeted analyses, with preliminary targeted screening.


Assuntos
Cromatografia Líquida , Monitoramento Ambiental/métodos , Peixes , Toxinas Marinhas/análise , Espectrometria de Massas em Tandem , Água/química , Animais , Toxinas Bacterianas/análise , Cianobactérias/química , Isótopos/análise , Microcistinas/análise , Peptídeos Cíclicos/análise , Saxitoxina/análise , Tropanos/análise , Uracila/análogos & derivados , Uracila/análise
20.
Anal Bioanal Chem ; 411(13): 2827-2837, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30982927

RESUMO

It is essential to be able to identify the source species and to determine the authenticity of traditional Chinese medicines (TCM) in order to prevent the use of false or inferior medicines. In this work, a stable and reliable method of discriminating among the three source species of Rhizoma Coptidis and checking the authenticity of Rhizoma Coptidis samples was established. The technique involved evaluating stable isotope ratios and the contents of multiple elements in samples along with the use of multivariate statistical techniques. The stable isotope ratios δ13C, δ15N, δ2H, and δ18O and the concentrations of various inorganic elements (Li, B, Na, Mg, Al, P, Si, K, Ca, Ti, Mn, Fe, Cu, Zn, Sr, and Ba) in authentic Rhizoma Coptidis samples from three source species (n = 56) and in counterfeit Rhizoma Coptidis samples (n = 39) were determined. The results showed that there were significant differences between the samples from different source species according to multivariate statistical analysis. The three species were clearly distinguished using hierarchical cluster analysis (HCA). Employing stepwise linear discriminant analysis (SLDA), a classification model for differentiating the three species was developed, and this model achieved 100% classification accuracy when applied to samples. In addition, authentic samples and counterfeit samples were successfully discriminated using stable isotope and multielement fingerprint analysis and orthogonal projections to latent structures discriminant analysis (OPLS-DA), and OPLS-DA models for checking the authenticity of Rhizoma Coptidis were established and verified. Therefore, stable isotope and multielement analysis combined with multivariate statistical analysis was shown to be a promising method of discriminating among the three source species of Rhizoma Coptidis and of establishing the authenticity of Rhizoma Coptidis samples. Graphical abstract.


Assuntos
Medicamentos de Ervas Chinesas/química , Análise por Conglomerados , Análise Discriminante , Contaminação de Medicamentos , Elementos , Isótopos/análise , Análise Multivariada
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