Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
1.
An Acad Bras Cienc ; 87(2): 569-94, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26131629

RESUMO

According to the demands of energy saving and carbon emission reduction, the water vs. energy nexus has become a major concern worldwide. Brazil occupies a singular position in the global energy system. A major portion of the Brazilian occupancies has electricity and the energy system expansion that, at first, possesses adequate means for supporting the economic growing may experience some turnovers. The Brazil determination through alternative fuels was a natural choice, given its large hydropower potential and land agricultural base. In the transportation sector Brazil has developed its energy matrix towards an important rate of ethanol and biodiesel. Although those fuels are low carbon emitter, they may probably not be an affordable alternative regarding land use, food security and water footprint. In this way, considering the recent advances in the exploration of oil from Pre-salt (9-15 million barrels) and the discovery of shale gas wells up to 245 tcf, together to unfavorable social and environmental issues associated to biofuels, the Brazilian energy matrix might turn back to the fossil fuels again. These represent challenges to the Brazilian policymakers and how they will be solved will reflect not only in Brazil but also to the world at large.

2.
Chemosphere ; 363: 142817, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38986788

RESUMO

Coastal ecosystems, such as coral reefs, are particularly vulnerable to mercury contamination due to direct contact with terrestrial sources. Here, we evaluated, for the first time, the concentration of mercury in coral reefs in the Southwestern Atlantic using the amphi-atlantic scleractinian coral Montastraea cavernosa. Sampling was realized over an extension of 200 km along different coral reefs. Our data show mercury values ranging from 0.01 to 0.27 mg kg-1 in the tissue and 0.001-0.06 mg kg-1 in the skeleton and higher values when compared to coral worldwide. The concentration of mercury in the tissue from Todos os Santos Bay was higher than in open sea regions but also higher compared to other coral reefs of the world, while the skeleton concentration did not indicate any differences when compared to the open sea regions. The data presented is of concern as we consider the importance of coral reefs and should be used in future environmental management planning.


Assuntos
Antozoários , Recifes de Corais , Monitoramento Ambiental , Mercúrio , Poluentes Químicos da Água , Animais , Antozoários/química , Poluentes Químicos da Água/análise , Mercúrio/análise , Ecossistema
3.
Sci Total Environ ; 952: 175913, 2024 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-39226965

RESUMO

Coastal marine ecosystems, such as coral reefs, are severely threatened by climate changes, overexploitation, and marine pollution. Particularly, environmental pollution caused by petroleum-derived substances is poorly studied in coral reefs in tropical developing countries, with a total absence of data about these contaminants in some regions. In this work, we determined the levels of conventional and unconventional PAHs in the tissue and skeleton of the coral Montastraea cavernosa in a seascape scale of the Southwest Atlantic. We sampled in 12 coral reefs adjacent to the coast along approximately 200 km. We found 14 PAHs, 2 Oxy-PAHs, and 15 Nitro-PAHs in the samples, and among them, benzo[a]pyrene, chrysene, benzo[a]anthracene, benzo[k]fluoranthene, indeno[1,2,3-c,d]pyrene and dibenz[a,h]anthracene, which are mutagenic, teratogenic and carcinogenic substances. Skeletons presented predominantly lower quantities of ∑PAHs than the respective tissue, except for the skeletons from one reef severely impacted by oil spills. The ∑PAHs levels were lower in a bay near an urbanized region than in open sea reefs. Diagnostic ratios indicate mixogenic sources, with the predominance of petrogenic origin. Our study provides the first occurrence of PAHs, Nitro-PAHs, and Oxy-PAHs distribution in corals from the Southwest Atlantic Ocean, and we expect that these data will help to evaluate any future impacts and management of this ecosystem.


Assuntos
Antozoários , Recifes de Corais , Monitoramento Ambiental , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Animais , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise , Oceano Atlântico
4.
Sci Rep ; 13(1): 4248, 2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36918617

RESUMO

We investigated if pristine and functionalized fullerenes could be actual constituents of fine atmospheric aerosols. Comprehensive profiles of fullerenes from 1 µL extracts were made through matrix laser desorption ionization Time-of-Flight Mass Spectrometry (MALDI-MS) within a few minutes. The ion with m/z 720, corresponding to [C60]-•, was identified as fullerene after 1 µL of α-cyano-4-hydroxycinnamic acid matrix solution was spotted over the dried extracts. The ions with the m/z corresponding to C70, C76, C84, C100, C118, C128, and C130 were also attributed to other fullerene species detected within the samples. The ion m/z 878 was found to be the fullerene derivative diethyl methano[60]fullerene dicarboxylate. Since ions of fragmented fullerene molecules were not detected even at high laser energies, we considered the fullerenes' occurring as original constituents of real atmospheric particle matrices instead of being formed as artifacts of the laser action on samples. Therefore, this protocol would be helpful in the understanding of the distribution of either pristine or functionalized fullerenes in the environment and their participation in atmospheric chemistry under typical conditions, as well as its application in vitro and in vivo (eco)toxicity studies.

5.
Sci Total Environ ; 877: 162868, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-36934938

RESUMO

The impact of petroleum exploitation and oil spills in marine ecosystems has increased over time. Among the concerns regarding these events, the impact on coral reefs stand out because this ecosystem has ecological and economic importance and is globally threatened. We performed a systematic review and bibliometric analysis of studies that determine polycyclic aromatic hydrocarbons (PAHs) in coral reefs, attempting to answer how the studies were distributed around the globe, the main environmental matrices and species of coral studied, the main PAHs found and their mean concentrations, and the methodology used. A bibliographic search resulted in 42 studies with worldwide distribution. The bibliometric results presented more explored terms, such as sediments and toxicology, and newly investigated terms, which should encourage a new area of study, such as those related to zooxanthellae and mucus. The main matrices studied in coral reefs are sediments, corals, and water, whereas air and other invertebrates have rarely been studied. Approximately 45 species of corals with several morphotypes have been reported. PAHs recommended by the United States Environmental Protection Agency (US EPA) were analyzed in all studies, while additional compounds were analyzed in only five. The methods used to determine hydrocarbons are predominantly the most traditional; however, for corals, studies have tended to separate tissue, zooxanthellae, skeleton, and mucus. In the future, we recommend investment in improving the capacity to detect non-conventional PAHs, more studies in regions that are rarely explored in developing countries, and the creation of databases to facilitate management planning on marine coasts.


Assuntos
Antozoários , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Animais , Recifes de Corais , Ecossistema , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/análise , Monitoramento Ambiental , Poluentes Químicos da Água/toxicidade , Poluentes Químicos da Água/análise
6.
Food Chem ; 370: 131062, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34537431

RESUMO

A simple method was developed to determine 14 endocrine-disrupting chemicals (EDCs) in bottled waters, based on dispersive micro-solid phase extraction (d-µ-SPE) and liquid chromatography-mass spectrometry (LC-MS). Extraction was optimized using 2 k-1 factorial and Doehlert experimental designs. Optimized conditions were 80 mg C18, 25 min extraction at 1000 rpm, and 6 min desorption time. Repeatability was below 17 % for all EDCs. LOD and LOQ varied from 1.60 ng L-1 (estradiol, E2) to 23.2 ng L-1 (dimethylphthalate, DMP) and from 5.33 ng L-1 (E2) to 77.3 ng L-1 (DMP). We found DMP and bisphenol A (BPA) in samples after the heat treatment. DMP was up to 58.7 µg L-1, while BPA was up to 1.34 µg L-1. Tolerance of daily intake (TDI) for DMP were 2.50-2.94 µg kg-1 day-1 (children) and 1.43-1.68 µg kg-1 day-1 (adults). TDI for BPA were 0.03-0.07 µg kg-1 day-1 (children) and 0.01-0.04 µg kg-1 day-1 (adults).


Assuntos
Água Potável , Disruptores Endócrinos , Águas Minerais , Poluentes Químicos da Água , Compostos Benzidrílicos/análise , Criança , Disruptores Endócrinos/análise , Humanos , Extração em Fase Sólida , Espectrometria de Massas em Tandem , Poluentes Químicos da Água/análise
7.
Sci Total Environ ; 851(Pt 1): 157965, 2022 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-35952874

RESUMO

In the present study, the Hg levels in freshly collected polychaete species and their associated sediments were evaluated from Todos os Santos Bay, Northeastern Brazil. Additionally, it was also measured the Hg distribution along the annelids' body parts (anterior region, abdomen, and posterior region). Total Hg concentration was as follows: 13.6-144 µg kg-1 (Scolelepis chilensis, deposit feeder), 8.2-122 µg kg-1 (Laeonereis acuta, deposit feeder), 95-612 µg kg-1 (Armandia agilis, deposit feeder); 96.6-206 µg kg-1 (Lumbrineris sp., carnivorous), 75.3-112 µg kg-1 (Goniada echinulate, carnivorous), and 115-198 µg kg-1 (Branchiomma sp., suspension feeder). In turn, Hg levels in sediments ranged from 2.77 ± 0.24 to 6.38 ± 0.15 µg kg-1. Hg concentrations found in polychaete soft tissues were higher than those found in the sediments. Specific habits, feeding behavior, trophic level, and stressful environmental conditions are the main factors affecting the Hg levels in the species studied. The bioaccumulation factor (BAF), contamination factor (CF), and ecological risk assessment (Er) were calculated. The BAF values were higher than 1 for all studied species, indicating Hg bioaccumulation in the annelids, but the low levels of CF e Er showed those Hg levels present low to no significant ecological risk for the biota and benthonic organisms living in the sediments. Finally, no statistically significant difference was observed for Hg concentration levels along the polychaete body parts.


Assuntos
Mercúrio , Poliquetos , Poluentes Químicos da Água , Animais , Oceano Atlântico , Baías , Monitoramento Ambiental , Sedimentos Geológicos , Mercúrio/análise , Poluentes Químicos da Água/análise
8.
Sci Total Environ ; 782: 146541, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-33839668

RESUMO

Microplastics (MPs) are emerging and ubiquitous contaminants which have been gaining prominence since the last decade to nowadays. This is due to their possible adverse effects in aquatic ecosystems as well as the huge amount of plastic waste exponentially generated around the globe. Plastics may be introduced either directly to water bodies or indirectly to the aquatic systems by being carried by the wind, from emissions of contaminated effluents, and soil leaching, among other processes. In turn, these debris may interact with organic and inorganic contaminants, such as polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and trace constituents, and with microorganisms. Although the abundance of microplastics from South Atlantic waters is among the highest found worldwide, the number of studies in these marine waters regarding MP contamination is still scarce. Additionally, there still are no consensus on the best sampling conditions, which may be underestimating MPs. In this way, adequate MPs studies regarding their distribution, exposure levels, chemical and biological interactions are highly suggested in order to better understand both environmental and human health potential risks. This review assessed advances in sampling, analytical methodologies, characterization and understanding of MP sources in these marine waters in comparison to data from other regions around the globe.

9.
Sci Rep ; 10(1): 3465, 2020 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-32103055

RESUMO

In this work we report the occurrence of powerful mutagenic 3-nitrobenzanthrone (3-NBA), in addition to 18 polycyclic aromatic hydrocarbons (PAHs), 6 oxygenated PAHs and 27 nitrated PAHs in polychaete worms. Benzanthrone (BA), another important mutagenic polycyclic aromatic compound (PAC) also was detected in the samples. Polychaete annelids have great ecological relevance, being widely distributed in different environmental conditions, from intertidal zones up to seven thousand feet deep areas. They are abundantly found in both contaminated and uncontaminated areas and, therefore, used as indicators of the pollution status of a given area. As we know, so far, most of these PACs has not been previously reported in living organisms before. The 3-NBA concentrations determined in this study were within 0.11-5.18 µg g-1. Other relevant PACs such as PAHs, quinones and nitro-PAHs were found in maximum concentrations at 0.013 µg g-1 (coronene) to 11.1 µg g-1 (benzo[k]fluoranthene), 0.823 µg g-1 (9,10-phenenthrenequinone) to 12.1 µg g-1 (1,4-benzoquinone) and 0.434 (1-nitronaphthalene) µg g-1 to 19.2 µg g-1 (6-nitrobenzo[a]pyrene), respectively. Principal component analysis (PCA), ternary correlations and diagnostic ratios were employed in order to propose probable sources for PACs. Although statistical analysis preliminarily has indicated both pyrogenic and petrogenic contributions, petrogenic sources were predominant reflecting the impacts of petroleum exploration and intensive traffic of boats in the study area.


Assuntos
Benzo(a)Antracenos/análise , Mutagênicos/análise , Poliquetos/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Animais , Benzo(a)Antracenos/isolamento & purificação , Benzo(a)Antracenos/metabolismo , Monitoramento Ambiental , Cromatografia Gasosa-Espectrometria de Massas , Limite de Detecção , Mutagênicos/metabolismo , Poliquetos/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/isolamento & purificação , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Análise de Componente Principal , Extração em Fase Sólida/métodos , Sonicação , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/isolamento & purificação , Poluentes Químicos da Água/metabolismo
10.
Talanta ; 217: 121033, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32498836

RESUMO

This study presents the development and application of a new analytical methodology for determination of free- and bound-carbonyl compounds (CC) (as the CC themselves and as the hydroxyalkylsulfonic acids - HASA, respectively) in airborne particles. Free- and bound-CC determination were done through reaction with 2,4-dinitrophenylhydrazine (2,4-DNPH) and analysis by UFLC-MS. The method was successfully validated, showing good figures for linearity (R2 ≥ 0.9937), sensibility (3 fg ˂ LOD ˂ 20 fg for methacrolein and heptanal, respectively) and repeatability (5.9% ˂ RSD ˂ 13%). The proposed method was successfully applied in real samples of inhalable atmospheric particulate matter (PM10) and urban dust certified reference material (SRM 1649 b). The main CC determined in the SRM 1649 b was formaldehyde (75.4 µg g-1 in the free form, and 1898 µg g-1 in the bound form). In addition, for the bound-CC form (HASA), concentrations were determined for acetaldehyde (60.3 µg g-1), acetone (20.5 µg g-1), acrolein (9.15 µg g-1), propionaldehyde (17.1 µg g-1) and valeraldehyde (12.2 µg g-1). For PM10 samples, formaldehyde (148 µg g-1) and acetaldehyde (28.9 µg g-1) were quantified as free aldehydes and as HASA (hydroxymethanelsulfonic acid and hydroxyethanesulfonic acid were 432 µg g-1 and 211 µg g-1, respectively). Other bound-CC were, on average, within 19.2 µg g-1 (acrolein) and 62.1 µg g-1 (valeraldehyde). For all samples, acetone, acrolein, propionaldehyde and valeraldehyde were quantified only as HASA (bound-CC). Therefore, we could identify and quantify six carbonyl compounds using the proposed method. It is worth mentioning the hydrolysis step was crucial for the correct quantification of the HASAs. This was, in turn, what enabled the quantification of a greater number of analytes in the airborne samples. Hence, this procedure was found to be comprehensive, precise, accurate and suitable to be employed for determination of free-CC and HASA (bound-CC) in atmospheric particulate samples.

11.
J Sep Sci ; 32(20): 3432-40, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19777456

RESUMO

Carbonyl compounds (CC) play an important role in beverage aroma since they may affect flavor of wines, brandies, and beers, among others. For this reason, it is necessary to identify and quantify CC through adequate analytical techniques. This study is a proposal of both developing and optimization of a new analytical methodology that allows investigate C(1)-C(8 )CC in wines simultaneously by quantifying even those ones that are predominantly present in the adduct form hydroxylalkylsulfonic acids (HASA). The HASA dissociation is undertaken by specific alkaline media (pH 11). The developed methodology employed the LC with UV/VIS detection (lambda = 365 nm) technique under gradient elution in the way to reach both free-CC and bound-CC quantification. Results showed that binary gradient system using eluent A (MeOH/ACN/H(2)O 74.5:0.5:25% v/v/v) and eluent B (MeOH) reached the best separation condition of both lower and higher molecular mass CC. This proposed method allowed simultaneous quantification of formaldehyde, acetaldehyde, propanone, furfuraldehyde, butyraldehyde, benzaldehyde, hexanaldehyde, 2-ethyl-hexanaldehyde, E-pent-2-en-1-al, and cyclohexanone--all of them were found in white wine (Moscato Canelli) and red wine (Shiraz) produced in the São Francisco Valley, in the Northeastern Region of Brazil--although this optimized method may probably be suitable for quantification of propionaldehyde, isobutyraldehyde, heptanaldehyde, octanaldehyde, benzaldehyde, and E-hex-2-en-1-al as well. We could not prove if this method is also able to determine the latter CC group since we have not found these substances present in detectable levels in our real samples considered in this study.


Assuntos
Aldeídos/análise , Cromatografia Líquida de Alta Pressão/métodos , Cetonas/análise , Vinho/análise , Peso Molecular
12.
Sci Rep ; 9(1): 1, 2019 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-30626917

RESUMO

Polycyclic aromatic compounds (PACs) are known due to their mutagenic activity. Among them, 2-nitrobenzanthrone (2-NBA) and 3-nitrobenzanthrone (3-NBA) are considered as two of the most potent mutagens found in atmospheric particles. In the present study 2-NBA, 3-NBA and selected PAHs and Nitro-PAHs were determined in fine particle samples (PM 2.5) collected in a bus station and an outdoor site. The fuel used by buses was a diesel-biodiesel (96:4) blend and light-duty vehicles run with any ethanol-to-gasoline proportion. The concentrations of 2-NBA and 3-NBA were, on average, under 14.8 µg g-1 and 4.39 µg g-1, respectively. In order to access the main sources and formation routes of these compounds, we performed ternary correlations and multivariate statistical analyses. The main sources for the studied compounds in the bus station were diesel/biodiesel exhaust followed by floor resuspension. In the coastal site, vehicular emission, photochemical formation and wood combustion were the main sources for 2-NBA and 3-NBA as well as the other PACs. Incremental lifetime cancer risk (ILCR) were calculated for both places, which presented low values, showing low cancer risk incidence although the ILCR values for the bus station were around 2.5 times higher than the ILCR from the coastal site.

13.
J Sep Sci ; 31(10): 1787-96, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18481323

RESUMO

This paper describes the development and optimization, by using multivariate analysis, of a GC-MS-SIM method for evaluation of the 16 polyaromatic hydrocarbons considered as priority pollutants in atmospheric particulate material by the US EPA. In order to assure an adequate separation in the shortest analysis time, a multivariate design was used to set the conditions of the oven temperature program. The optimization process was carried out using factorial fractional design and Box-Behnken design. The following factors were evaluated: initial temperature, temperature rate #1, intermediary temperature, temperature rate #2, and final temperature. The optimized conditions were set at: 70 degrees C (2 min) --> 200 degrees C (30 degrees C/min, 5 min) --> 300 degrees C (5 degrees C/min, 1.67 min). Moreover, we have also optimized the injector temperature as 310 degrees C and sampling time as 0.8 min. The total analysis time was 33 min. Validation of GC-MS-SIM yielded satisfactory results for repetitivity of the detector response and retention times, and linearity of calibration curves. LOD were established as 0.13-0.34 ng/mL (peak area) and 0.18-0.72 ng/mL (peak height). The method has been shown to be appropriate for the analysis of samples of atmospheric particulate material and/or other environmental matrices.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas/métodos , Hidrocarbonetos Policíclicos Aromáticos/análise , Calibragem , Cromatografia/instrumentação , Cromatografia/métodos , Meio Ambiente , Monitoramento Ambiental/instrumentação , Monitoramento Ambiental/métodos , Poluentes Ambientais , Cromatografia Gasosa-Espectrometria de Massas/instrumentação , Modelos Estatísticos , Análise Multivariada , Reprodutibilidade dos Testes , Temperatura , Fatores de Tempo
14.
J Agric Food Chem ; 55(21): 8670-80, 2007 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-17877410

RESUMO

The presence of carbonyl compounds (CCs) in wines has sparked the interest of researchers in several countries. The quantification of some of these compounds has been used as a parameter of quality for many fermented beverages. Although present in minute quantities (except for acetaldehyde), they have a strong olfactory impact. In addition, the CCs found in wines have a strong affinity for bisulfite and can form stable adducts, which will also interfere in the characteristics of aroma. The greatest challenge, however, is to predict which CCs have the strongest affinity for S(IV) and what conditions favor this interaction. To better understand the reaction of CC-bisulfite adduct formation (HASA), this study has evaluated the profile of 22 CCs in a "synthetic wine" containing bisulfite and in 10 real samples of different wines from the São Francisco Valley, northeastern Brazil. On the basis of principal component analysis (PCA) and dissociation constants, the results revealed that aliphatic aldehydes form adducts with S(IV), whereas ketones, cyclic aldehydes, and trans-alkenes interact weakly and are found predominantly in their free form. These results revealed also that pH 10 and 11 were defined as the most appropriate for CC-SO 2 adduct dissociation, and the total CCs were quantified reliably.


Assuntos
Ácidos Sulfônicos/química , Vinho/análise , Aldeídos/análise , Aldeídos/química , Alquilação , Estabilidade de Medicamentos , Hidroxilação , Sulfitos/análise , Sulfitos/química , Ácidos Sulfônicos/análise
15.
Sci Rep ; 7(1): 2267, 2017 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-28536439

RESUMO

The intensive use of pesticides such as herbicides, insecticides, fungicides and acaricides has been lead to ubiquitous contamination, being present not only in soils, water bodies and/or crops, but also in the atmosphere. Considering the massive amount of pesticides employed globally, together to their persistence, this may be an important concern regarding air quality and human health worldwide. In the present study we developed a green sensitive sample preparation method for determination of nine organophosphates, two pyrethroids, one carbamate, and one strobirulin in PM2.5 collected in a tropical coastal area in the Southern Hemisphere for the first time. Extraction of PM2.5 sample masses, as low as 206 µg, were performed in a miniaturized device using 500 µL of a mixture containing 18% acetonitrile in dichloromethane followed by sonication for 23 minutes and injection into GC-MS. A total of 12 pesticides were identified and quantified successfully, among them, eight banned pesticides. A risk assessment exposure and cancer risk for possible carcinogenic pesticides (bifenthrin, malathion, parathion and permethrin) were performed for exposure of adults, children and infants. Hazard Quotient and cumulative exposure for organophosphate and pyrethroid pesticides were less than 1, showing that cumulative risk is within acceptable range.

16.
J Chromatogr A ; 1435: 6-17, 2016 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-26830633

RESUMO

The method allowed simultaneous characterization of PAHs, nitro-PAHs and quinones in atmospheric particulate matter. This method employs a miniaturized micro-extraction step that uses 500 µL of an acetonitrile-dichloromethane mix and instrumental analysis by means of a high-resolution GC-MS. The method was validated using the SRM1649b NIST standard reference material as well as deuterated internal standards. The results are in good agreement with the certified values and show recoveries between 75% and 145%. Limit of detection (LOD) values for PAHs were found to be between 0.5 pg (benzo[a]pyrene) to 2.1 pg (dibenzo[a,h]anthracene), for nitro-PAHs ranged between 3.2 pg (1-nitrobenzo[e]pyrene) and 22.2 pg (3-nitrophenanthrene), and for quinones ranged between 11.5 pg (1,4-naphthoquinone) and 458 pg (9,10-phenanthraquinone). The validated method was applied to real PM10 samples collected on quartz fiber filters. Concentrations in the PM10 samples ranged from 0.06 to 15 ng m(-3) for PAHs, from

Assuntos
Monitoramento Ambiental/métodos , Cromatografia Gasosa-Espectrometria de Massas , Material Particulado/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Atmosféricos/análise , Benzo(a)pireno/análise , Limite de Detecção , Naftoquinonas/análise , Solventes/química
17.
Talanta ; 117: 168-75, 2013 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-24209326

RESUMO

The present study proposes a fast and simple analytical methodology employing C18 SPE cartridges (for preconcentration and clean-up), and a ultra-fast liquid chromatography coupled to fluorescence detector (UFLC-FLD) for determination of the following endocrine disrupters (ED): bisphenol A (BPA), 4-n-nonylphenol (4NNP), 4-n-octylphenol (4NOP), 4-t-octylphenol (4TOP), estriol (E3), estrone (E1), 17ß-estradiol (E2) and 17α-ethynylestradiol (EE2) in seawater. The proposed method was developed, optimized and validated. Separation was done by a total running time of 10 min in a Shim-pack XR-ODS C-18 (2.0 mm ID × 50 mm) chromatographic column, mobile phases were acetonitrile/ultra-pure water under gradient programming; eluent flow rate at 0.120 mL min(-1); column temperature set at 60 °C; emission wavelength of 306 nm and excitation wavelength of 280 nm. The method was validated through assessment of the following parameters: linear range, linearity, selectiveness, precision, recovery test, limit of detection (LOD), and limit of quantification (LOQ). Recoveries ranged from 91% (for EE2) to 104% (for 4NNP) and also was found a suitable repeatability (RSD <4.5%) for all considered compounds. LOD and LOQ ranged from 2.0 ng L(-1) (EE2) to 23 ng L(-1) (E1) and 9.3 ng L(-1) (EE2) to 96 ng L(-1) (E1), respectively. The analytical method using SPE UFLC-FLD was applied to seawater samples collected from Todos os Santos Bay (BTS), Brazil to determine the concentration of eight ED.


Assuntos
Cromatografia Líquida/métodos , Disruptores Endócrinos/análise , Estradiol/análise , Fenóis/análise , Água do Mar/química , Acetonitrilas , Brasil , Estradiol/análogos & derivados , Fluorescência , Limite de Detecção , Reprodutibilidade dos Testes
18.
J Chromatogr A ; 1266: 17-23, 2012 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-23116797

RESUMO

The present study proposes an analytical methodology that employs ion chromatography-conductivity detection for simultaneous quantification of inorganic (F(-), Cl(-), NO(3)(-), SO(4)(2-), and PO(3)(-)), monocarboxylate (HCOO(-), CH(3)COO(-), propionate, n-butyrate, lactate, and pyruvate), dicarboxylate (oxalate and succinate), and tricarboxylate anions (citrate), as well as crustal cations (Li(+), Na(+), K(+), NH(4)(+), Ca(2+), Mg(2+)) at low pgm(-3) range in airborne particle samples in one single run. The optimized conditions for anions were as follows: 0.6 mmol L(-1) KOH for 0-14 min, 0.6-15 mmol L(-1) KOH 14-20 min, 15-38 mmol L(-1) KOH during 20-32 min and finally returned to 0.6 mmol L(-1) for a period of 3 min, thereafter the eluent flow rate was 0.38 mL min(-1). Similarly, for cations, isocratic elution was adjusted to 0.36 mL min(-1) at 17.5 mmol L(-1) H(2)SO(4). LOD ranged 3.0-130 pgm(-3) and LOQ was within 10-400 pgm(-3) (Li(+) and PO(4)(3-), respectively) as well as recoveries ranged 89% (Ca(2+)) to 120% (Li(+)). Major ions were successfully determined in real PM1 and PM2.5 samples. The method used here was found to be a comprehensive, simple, cheap and reliable procedure for studying ions in particulate matter (PM) samples even those from remote areas or near ecosystem natural conditions.


Assuntos
Ar/análise , Cromatografia por Troca Iônica/métodos , Material Particulado/análise , Ânions/análise , Ácidos Carboxílicos/química , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA