Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 42
Filtrar
Mais filtros

Bases de dados
Tipo de documento
Intervalo de ano de publicação
1.
Environ Monit Assess ; 195(3): 386, 2023 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-36764975

RESUMO

Potential pollution of mining environmental liabilities' locations can be preliminarily and efficiently assessed by the potential generation of acid mine drainage and indices of contamination. This research evaluates the potential pollution by potentially toxic elements at locations with uranium mining liability evidence, using the net acid generation test and determining the background values to estimate acid mine drainage and indices of contamination. Sixty soil samples were collected, and the mineralogy and potentially toxic elements' total contents were determined by x-ray diffraction and optical spectrometry. The findings suggest that the soils related to a specific lithology might not present potential acid mine drainage generation but potential soil and sediment contamination. Future research is recommended on applying leaching tests to identify which potentially toxic elements are effectively being solubilized. Finally, it can be concluded that the study area's potential contamination is relatively low overall.


Assuntos
Metais Pesados , Poluentes do Solo , Urânio , Urânio/análise , México , Monitoramento Ambiental/métodos , Poluentes do Solo/análise , Solo/química , Mineração , Ácidos/análise , Metais Pesados/análise
2.
Molecules ; 27(19)2022 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-36235101

RESUMO

Polyphenols, organic acids and metal ions are an important group of compounds that affect the human health and quality of food and beverage products, including wines. It is known that a specific correlation between these groups exist. While wines coming from the New World and the Old World countries are extensively studied, wines coming from cool-climate countries are rarely discussed in the literature. One of the goals of this study was to determine the elemental composition of the wine samples, which later on, together as polyphenols and organic acids content, was used as input data for chemometric analysis. The multivariate statistical approach was applied in order to find specific correlations between the selected group of compounds in the cool-climate wines and the features that distinguish the most and differ between red and white wines and rosé wines. Moreover, special attention was paid to resveratrol and its correlation with selected wine constituents.


Assuntos
Vinho , Ácidos/análise , Humanos , Metais/análise , Compostos Orgânicos/análise , Polifenóis/análise , Resveratrol/análise , Vinho/análise
3.
Acta Sci Pol Technol Aliment ; 20(2): 127-133, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33884851

RESUMO

BACKGROUND: Cold-pressed berry seed oils are used for consumption and other applications including skin and hair care. They are natural products which gain the attention of customers. In this study, strawberry, raspberry and blackberry seed oils used for cosmetic purposes, purchased from three different European producers, were analyzed. The aim of the study was to assess the quality and oxidative stability of the berry fruit oils, thus they were analyzed after purchase and after 4 and 8 weeks of storage at room temperature. METHODS: Acid and peroxide values were determined in the tested oils, as was oxidative stability, which was measured using pressure differential scanning calorimetry (PDSC). Additionally, fatty acid profiles and thei. RESULTS: nd. Cold-pressed berry seed oils are used for consumption and other applications including skin and hair care. They are natural products which gain the attention of customers. In this study, strawberry, raspberry and blackberry seed oils used for cosmetic purposes, purchased from three different European producers, were analyzed. The aim of the study was to assess the quality and oxidative stability of the berry fruit oils, thus they were analyzed after purchase and after 4 and 8 weeks of storage at room temperature. Materials and methods. Acid and peroxide values were determined in the tested oils, as was oxidative stability, which was measured using pressure differential scanning calorimetry (PDSC). Additionally, fatty acid profiles and their distribution at sn-1,3 and sn-2 positions of triacylglycerols were characterized. Results, principal. Most of the fatty acids of the tested berry seed oils are polyunsaturated fatty acids (67.04-74.95%). The results show the low quality of the tested oils in terms of oxidative stability (high peroxide values: 21.9-249.6 mEq O2/kg oil). CONCLUSIONS: Based on this study, it is necessary to evaluate the effects of these products on the body. Moreover, standards clarifying the oxidation of cosmetic oils should be set internationally.


Assuntos
Cosméticos/química , Ácidos Graxos Insaturados/análise , Fragaria/química , Óleos de Plantas/química , Rubus/química , Sementes/química , Ácidos/análise , Temperatura Baixa , Europa (Continente) , Peroxidação de Lipídeos , Oxirredução , Peróxidos/análise , Óleos de Plantas/normas , Triglicerídeos/química
4.
Int J Food Microbiol ; 334: 108800, 2020 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-32829187

RESUMO

The present study investigated the presence, growth potential, and public health risk posed by Listeria monocytogenes in a ready-to-eat "shrimp cocktail". The pathogen was detected in 4 out of the 104 samples, and there were no counts above the enumeration limit (1 Log colony-forming unit (CFU)/g); the product was a suitable substrate for pathogen growth owing to its chemical/physical properties. A stochastic quantitative microbial risk assessment (QMRA) was performed to estimate the expected number of invasive listeriosis cases caused by the consumption of 10,000 servings of the product on the last day of its shelf life, considering a population comprising healthy consumers, those susceptible, and transplant recipients. The model predicted no cases for this scenario. Uncertainties were included by considering alternative scenarios; even when considering an increased mean bacterial concentration (up to 3-4 Log CFU/g), no cases were estimated. Following a producer's demand, the exposure assessment model was also used to estimate the probability of the product exceeding the threshold of 2 log CFU/g during the shelf life. The possibility of Listeria growth in the product could not be avoided. Therefore, a modification of the production process was tested to re-classify the product as unsuitable for Listeria growth (EC Reg. 2073/2005). The shrimps were conditioned in three different organic acid solutions comprising: acetic acid (1500 ppm) (A); benzoic acid (1500 ppm) + acetic acid (500 ppm) + lactic acid (750 ppm) (BLA); and lactic acid (4500 ppm) + sodium acetate (2500 ppm) (LSA). Testing was conducted over various treatment durations (1 day-5 days). Treatment for 2 days in the LSA solution was selected based on efficacy, the absence of consumer-perceptible sensorial modifications, and the producers' production rate requirements. The concentration of L. monocytogenes decreased when the new process was applied, which confirmed the usefulness and effectiveness of the treatment relative to the traditional process. Thus, the product obtained by the modified production process did not support the growth of L. monocytogenes.


Assuntos
Exposição Dietética/prevenção & controle , Microbiologia de Alimentos/métodos , Listeria monocytogenes/crescimento & desenvolvimento , Listeriose/prevenção & controle , Alimentos Marinhos/microbiologia , Ácidos/análise , Ácidos/farmacologia , Animais , Contagem de Colônia Microbiana , Exposição Dietética/análise , Manipulação de Alimentos , Humanos , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/isolamento & purificação , Listeriose/epidemiologia , Medição de Risco , Alimentos Marinhos/análise
5.
PLoS One ; 15(5): e0232853, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32374780

RESUMO

OBJECTIVE: The choice of the most suitable litter treatment should be based on scientific evidence. This systematic review assessed the effectiveness of litter treatments on ammonia concentration, pH, moisture and pathogenic microbiota of the litter and their effects on body weight, feed intake, feed conversion and mortality of broilers. METHODS: The systematic literature search was conducted using PubMed (Medline), Google Scholar, ScienceDirect and Scielo databases to retrieve articles published from January 1998 to august 2019. Means, standard deviations and sample sizes were extracted from each study. The response variables were analyzed using the mean difference (MD) or standardized mean difference (SMD), (litter treatment minus control group). All variables were analyzed using random effects meta-analyses. RESULTS: Subgroup meta-analysis revealed that acidifiers reduce pH (P<0.001), moisture (P = 0.002) ammonia (P = 0.011) and pathogenic microbiota (P <0.001) of the litter and improves the weight gain (P = 0.019) and decreases the mortality rate of broilers (P<0.001) when compared with controls. Gypsum had a positive effect on ammonia reduction (P = 0.012) and improved feed conversion (P = 0.023). Alkalizing agents raise the pH (P = 0.035), worsen feed conversion (P<0.001), increase the mortality rate (P <0.001), decrease the moisture content (P<0.001) and reduce the pathogenic microbiota of the litter (P<0.001) once compared to controls. Superphosphate and adsorbents reduce, respectively, pH (P<0.001) and moisture (P = 0.007) of the litter compared to control groups. CONCLUSION: None of the litter treatments influenced the feed intake of broilers. Meta-analyses of the selected studies showed positive and significant effects of the litter treatments on broiler performance and litter quality when compared with controls. Alkalizing was associated with worse feed conversion and high mortality of broilers.


Assuntos
Criação de Animais Domésticos/métodos , Galinhas/fisiologia , Abrigo para Animais , Ácidos/análise , Ácidos/farmacologia , Ácidos/toxicidade , Álcalis/análise , Álcalis/farmacologia , Álcalis/toxicidade , Amônia/análise , Ração Animal , Animais , Doenças das Aves/mortalidade , Peso Corporal , Galinhas/crescimento & desenvolvimento , Comportamento Alimentar , Abrigo para Animais/estatística & dados numéricos , Umidade , Concentração de Íons de Hidrogênio , Microbiota , Gerenciamento de Resíduos , Aumento de Peso
6.
PLoS One ; 15(4): e0231589, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32320411

RESUMO

The Arctic Ocean is an early warning system for indicators and effects of climate change. We use a novel combination of experimental and time-series data on effects of ocean warming and acidification on the commercially important Northeast Arctic cod (Gadus morhua) to incorporate these physiological processes into the recruitment model of the fish population. By running an ecological-economic optimization model, we investigate how the interaction of ocean warming, acidification and fishing pressure affects the sustainability of the fishery in terms of ecological, economic, social and consumer-related indicators, ranging from present day conditions up to future climate change scenarios. We find that near-term climate change will benefit the fishery, but under likely future warming and acidification this large fishery is at risk of collapse by the end of the century, even with the best adaptation effort in terms of reduced fishing pressure.


Assuntos
Biomassa , Mudança Climática , Pesqueiros/tendências , Gadus morhua/fisiologia , Água do Mar/química , Ácidos/análise , Animais , Pesqueiros/economia , Pesqueiros/estatística & dados numéricos , Modelos Estatísticos
7.
Chemosphere ; 219: 695-703, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30557726

RESUMO

A passive treatment plant, located in the Iberian Pyrite Belt (Huelva, Southwest Spain), was designed for acid mine drainage remediation. Since its installation, the improvement of water quality in terms of hydrochemical composition has been demonstrated successfully. However, according to the Water Framework Directive, the treated effluent must have ecological values for potential living. The freshwater clam Corbicula fluminea was chosen to carry out bioassessments (survival, biomarker responses, and metal bioaccumulation in soft tissue) with effluents from the mining site, as well as, products from the passive treatment plant in order to determine the level of quality of that water from the biological point of view in toxicity tests. Results discarded mortality as endpoint for biomonitoring purposes. Only the lipid peroxidation of the cell membrane evidenced significant responses, even in correlation with the pollution degree of each effluent. Regarding bioaccumulation, some elements displayed a strong relationship (Fe, Cu, Co, and Zn) between concentrations in the environment and in the tissue. As final conclusion, the usage of the Asian clam was validated as biomonitor tool in short term exposure to acid mine drainage, and, as early warning responses (72 h), the chosen parameters would be lipid peroxidation and bioaccumulation of a specific set of elements (Fe, Cu, Co, Zn). Ecological water quality levels reached by the passive treatment plant were in agreement with the efficiency of hydrochemical improvements.


Assuntos
Corbicula/química , Monitoramento Ambiental/métodos , Recuperação e Remediação Ambiental , Mineração , Qualidade da Água , Ácidos/análise , Animais , Bivalves/química , Água Doce/química , Metais Pesados/análise , Espanha , Poluentes Químicos da Água/análise
8.
J Sci Food Agric ; 97(5): 1646-1655, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27436661

RESUMO

BACKGROUND: The grafting of watermelons (Citrullus lanatus) is a common technique that increases yield under stressful soil conditions. The most common rootstocks for watermelons are Cucurbita hybrids. However, they often have a negative impact on fruit quality. Exploiting novel Citrullus germplasm such as citron melon (Citrullus lanatus var. citroides) is an alternative to avoid these quality problems. RESULTS: Citron melon has been validated as watermelon rootstock, comparing its effects on watermelon quality to those of Cucurbita hybrids. Larger fruits with thicker rinds were observed in fruits from plants grafted onto both citron and Cucurbita rootstocks. The citron melon had no significant effect on flesh sugars or acid profiles compared to non-grafted watermelons, except for an increase in glucose and malic acid content, which also occurred in the Cucurbita rootstocks. The aroma profile of fruits produced on citron melon was similar to that of the non-grafted and self-grafted controls. The citron rootstock did not display the increased levels of (Z)-6-nonen-1-ol (a compound associated with pumpkin-like odors) found in fruits produced with Cucurbita hybrids. CONCLUSION: The low impact of citron melon rootstock on fruit quality, along with the enhanced resistance against nematodes, make the citron a promising alternative to Cucurbita rootstocks. © 2016 Society of Chemical Industry.


Assuntos
Citrullus/química , Citrullus/crescimento & desenvolvimento , Ácidos/análise , Cucurbita , Frutas/química , Frutas/crescimento & desenvolvimento , Monossacarídeos/análise , Odorantes , Raízes de Plantas , Espanha , Compostos Orgânicos Voláteis/análise
9.
Spectrochim Acta A Mol Biomol Spectrosc ; 159: 219-22, 2016 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-26851490

RESUMO

Four rapid, simple, accurate and precise spectrophotometric methods were used for the determination of ciprofloxacin in the presence of its acidic degradation product. The methods under study are ratio derivative, ratio difference, mean centering and dual wavelength. All the methods were validated according to the ICH guidelines and the obtained accuracy, precision and repeatability were found to be within the acceptable limits. The selectivity of the proposed methods was tested using laboratory prepared mixtures and assessed by applying the standard addition technique. So, they can be used for the routine analysis of ciprofloxacin in quality-control laboratories.


Assuntos
Antibacterianos/análise , Ciprofloxacina/análise , Espectrofotometria/métodos , Ácidos/análise , Análise de Variância , Estabilidade de Medicamentos , Limite de Detecção , Reprodutibilidade dos Testes , Espectrofotometria/economia
10.
Environ Sci Pollut Res Int ; 23(10): 9871-90, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26856868

RESUMO

Sediment samples from the coastal area of Asaluyeh harbor were collected during autumn and spring 2015. The acid-volatile sulfide (AVS) and simultaneously extracted metals (SEMs) were measured to assess the sediment quality and potential ecological risks. The average concentrations (and relative standard deviation (RSD)) of AVS in the industrial sediments were 12.32 µmol/g (36.91) and 6.34 µmol/g (80.05) in autumn and spring, respectively, while in the urban area, these values were 0.44 µmol/g (123.50) and 0.31 µmol/g (160.0) in autumn and spring, respectively. The average concentrations of SEM (and RSD) in the industrial sediments were 15.02 µmol/g (14.38) and 12.34 µmol/g (20.65) in autumn and spring, respectively, while in the urban area, these values were 1.10 µmol/g (43.03) and 1.06 µmol/g (55.59) in autumn and spring, respectively. Zn was the predominant component (34.25-86.24 %) of SEM, while the corresponding value for Cd, much more toxic ingredient, was less than 1 %. Some of the coastal sediments in the harbor of Asaluyeh (20 and 47 % in autumn and spring, respectively) had expected adverse biological effects based on the suggested criterion by United States Environmental Protection Agency (USEPA), while most stations (80 and 53 % in autumn and spring, respectively) had uncertain adverse effects.


Assuntos
Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Indústrias , Metais Pesados/análise , Sulfetos/análise , Poluentes Químicos da Água/análise , Ácidos/análise , Disponibilidade Biológica , Oceano Índico , Metais Pesados/toxicidade , Estações do Ano , Análise Espaço-Temporal , Sulfetos/toxicidade , Urbanização , Volatilização , Poluentes Químicos da Água/toxicidade
12.
Mar Pollut Bull ; 97(1-2): 431-439, 2015 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-26028168

RESUMO

The risks of heavy metal in Futian mangrove forest sediment were assessed using the acid-volatile sulfide (AVS) and simultaneously extracted metals (SEM) methods. The results indicated that AVS distributions were more variable than the SEM distributions at all 16 sampling sites. The positive correlation between AVS and SEM indicated that their similar formative and existing conditions and that AVS acted as an important carrier for SEM. The major SEM component was Zn (69.7.3-94.2%), whereas the Cd contribution (the most toxic metal present) to SEM was no more than 1%. The possible adverse effects caused by heavy metals at ten sampling sites may be due to higher levels of SEMs, rather than AVSs. The total organic carbon (TOC) was an important metal-binding phase in the sediments. Taking into account the TOC concentration, there were no adverse effects due to heavy metals in any of the Futian mangrove forest sediments.


Assuntos
Monitoramento Ambiental/métodos , Florestas , Sedimentos Geológicos/análise , Metais Pesados/análise , Sulfetos/análise , Poluentes Químicos da Água/análise , Ácidos/análise , Baías , China , Medição de Risco , Volatilização , Áreas Alagadas
13.
Environ Monit Assess ; 187(6): 374, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26009157

RESUMO

Acid mine drainage (AMD) gives rise to several problems in sulfide-bearing mineral deposits whether in an ore body or in the mining wastes and tailings. Hence, several methods and parameters have been proposed to evaluate the acid-producing and acid-neutralizing potential of a material. This research compares common static methods for evaluation of acid-production potential of mining wastes in the Muteh gold mines by using 62 samples taken from six waste dumps around Senjedeh and Chah-Khatoun mines. According to a detailed mineralogical study, the waste materials are composed of mica-schist and quartz veins with a high amount of pyrite and are supposed to be susceptible to acid production, and upon a rainfall, they release acid drainage. All parameters introduced in different methods were calculated and compared in this research in order to predict the acid-generating and neutralization potential, including APP, NNP, MPA, NPR, and NAGpH. Based on the analytical results and calculation of different parameters, all methods are in a general consensus that DWS-02 and DWS-03 waste dumps are acid-forming which is clearly attributed to high content of pyrite in samples. DWS-04 is considered as non-acid forming in all methods except method 8 which is uncertain about its acid-forming potential and method 7 which considers a low potential for it. DWC-01 is acid-forming based on all methods except 8, 9, 10, and 11 which are also uncertain about its potential. The methods used are not reached to a compromise on DWS-01 and DWC-02 waste dumps. It is supposed that method 7 gives the conservationist results in all cases. Method 8 is unable to decide on some cases. It is recommended to use and rely on results provided by methods 1, 2, 3, and 12 for taking decisions for further studies. Therefore, according to the static tests used, the aforementioned criteria in selected methods can be used with much confidence as a rule of thumb estimation.


Assuntos
Ácidos/análise , Mineração , Monitoramento Ambiental , Ouro , Concentração de Íons de Hidrogênio , Irã (Geográfico) , Ferro , Minerais , Sulfetos , Instalações de Eliminação de Resíduos
14.
Food Chem ; 178: 327-30, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25704719

RESUMO

Milk is the largest source of iodine in UK diets and an earlier study showed that organic summer milk had significantly lower iodine concentration than conventional milk. There are no comparable studies with winter milk or the effect of milk fat class or heat processing method. Two retail studies with winter milk are reported. Study 1 showed no effect of fat class but organic milk was 32.2% lower in iodine than conventional milk (404 vs. 595 µg/L; P<0.001). Study 2 found no difference between conventional and Channel Island milk but organic milk contained 35.5% less iodine than conventional milk (474 vs. 306 µg/L; P<0.001). UHT and branded organic milk also had lower iodine concentrations than conventional milk (331 µg/L; P<0.001 and 268 µg/L: P<0.0001 respectively). The results indicate that replacement of conventional milk by organic or UHT milk will increase the risk of sub-optimal iodine status especially for pregnant/lactating women.


Assuntos
Ácidos/análise , Iodo/análise , Leite/química , Animais , Bovinos , Manipulação de Alimentos , Alimentos Orgânicos/análise , Alimentos Orgânicos/economia , Leite/economia , Valor Nutritivo , Estações do Ano
15.
Environ Monit Assess ; 188(10): 554, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27613290

RESUMO

This paper reports the bioavailability of the metals (cadmium, copper, zinc, lead, and nickel) in sediment samples collected in seven stations from the São Paulo Estuary, Todos os Santos Bay, Brazil. The bioavailability was determined by employing the technique "acid-volatile sulfide (AVS) and simultaneously extracted metal (SEM)". The elements cadmium, copper, lead, and zinc were determined using differential pulse anodic stripping voltammetry (DPASV), while nickel was quantified utilizing electrothermal atomic absorption spectrometry (ET AAS). The accuracy of these methods was confirmed using a certified reference material of estuarine sediment (NIST 1646). The sulfide was quantified using potentiometry with selective electrode and the organic matter determination employing an indirect volumetric method using potassium dichromate and iron(II) sulfate solutions. The bioavailability of the metals was estimated by relationship between the concentration of AVS and the sum of the concentrations of the simultaneously extracted metals (ΣSEM), considering a significant toxicity when (ΣSEM)/(AVS) is higher than 1. The bioavailability values in the seven stations studied varied from 0.93 to 1.31 (June, 2014) and from 0.34 to 0.58 (September, 2014). These results demonstrated a critical condition of toxicity (bioavailability >1) in six of the seven sediment samples collected during the rainy season (June, 2014). In the other period (September, 2014), the bioavailability was always lower than 1 for all sediment samples collected in the seven stations. The individual values of the concentrations of the five metals were compared with the parameters PEL (probable effects level) and TEL (threshold effects level), which are commonly employed for characterization of ecological risk in environmental systems. This comparison revealed that all metals have concentrations lower than the PEL and only zinc and lead in some stations have contents higher than the TEL. The bioavailability evaluation and the concentrations achieved for the five elements in the sediments samples analyzed demonstrated that the ecosystem studied does not present an environmental risk.


Assuntos
Baías/análise , Disponibilidade Biológica , Monitoramento Ambiental , Sedimentos Geológicos/análise , Metais Pesados/análise , Ácidos/análise , Brasil , Cádmio/análise , Cobre/análise , Estuários , Sedimentos Geológicos/química , Intoxicação por Metais Pesados , Chumbo/análise , Níquel/análise , Intoxicação , Análise de Componente Principal , Sulfetos/análise , Zinco/análise
16.
J Chromatogr A ; 1370: 70-9, 2014 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-25454131

RESUMO

Metabolic profiling has become an important tool in biological research, and the chromatographic separation of metabolites coupled with mass spectrometric detection is the most frequently used approach for such studies. The establishment of robust chromatographic methods for comprehensive coverage of the anionic metabolite pool is especially challenging. In this study, the development of a capillary ion exchange chromatography (capIC) - negative ESI tandem mass spectrometry (MS/MS) workflow for the quantitative profiling of the phosphometabolome (e.g., sugar phosphates and nucleotides) is presented. The chromatographic separation and MS/MS conditions were optimized, and the precision of repetitive injections and accuracy in terms of error percentage to true concentration were assessed. The precision is excellent for a capillary flow system with an average CV% of 8.5% for a 50-fmol standard injection and in the lower 2.4-4.4% range for higher concentrations (500-7,500 fmol). The limit of detection (LOD) ranges from 1 to 100 nM (5-500 fmol injected on column), and the limit of quantitation (LOQ) ranges from 1 to 500 nM (5-2,500 fmol injected on column). A fast gradient method with the injection of 50% methanol in water between analytical samples is needed to eliminate carry-over and ensure optimal re-equilibration of the column. Finally, the quantitative applicability of the system was tested on real biological matrices using the constant-volume standard addition method (SAM). Extracts of the human kidney Hek293 cell line were spiked with increasing concentrations of standards to determine the concentration of each metabolite in the sample. Forty-four metabolites were detected with an average uncertainty of 4.1%. Thus, the capIC-MS/MS method exhibits excellent selectivity, sensitivity and precision for the quantitative profiling of the phosphometabolome.


Assuntos
Ácidos/análise , Cromatografia por Troca Iônica/métodos , Metaboloma , Espectrometria de Massas em Tandem/métodos , Ânions/química , Células HEK293 , Humanos , Limite de Detecção , Fosforilação , Espectrometria de Massas por Ionização por Electrospray
17.
Environ Sci Pollut Res Int ; 21(23): 13602-14, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25028324

RESUMO

Sea cucumbers are dominant invertebrates in several ecosystems such as coral reefs, seagrass meadows and mangroves. As bioturbators, they have an important ecological role in making available calcium carbonate and nutrients to the rest of the community. However, due to their commercial value, they face overexploitation in the natural environment. On top of that, occurring ocean acidification could impact these organisms, considered sensitive as echinoderms are osmoconformers, high-magnesium calcite producers and have a low metabolism. As a first investigation of the impact of ocean acidification on sea cucumbers, we tested the impact of short-term (6 to 12 days) exposure to ocean acidification (seawater pH 7.7 and 7.4) on two sea cucumbers collected in SW Madagascar, Holothuria scabra, a high commercial value species living in the seagrass meadows, and H. parva, inhabiting the mangroves. The former lives in a habitat with moderate fluctuations of seawater chemistry (driven by day-night differences) while the second lives in a highly variable intertidal environment. In both species, pH of the coelomic fluid was significantly negatively affected by reduced seawater pH, with a pronounced extracellular acidosis in individuals maintained at pH 7.7 and 7.4. This acidosis was due to an increased dissolved inorganic carbon content and pCO2 of the coelomic fluid, indicating a limited diffusion of the CO2 towards the external medium. However, respiration and ammonium excretion rates were not affected. No evidence of accumulation of bicarbonate was observed to buffer the coelomic fluid pH. If this acidosis stays uncompensated for when facing long-term exposure, other processes could be affected in both species, eventually leading to impacts on their ecological role.


Assuntos
Equilíbrio Ácido-Base , Ecossistema , Holothuria/metabolismo , Água do Mar/química , Ácidos/análise , Álcalis , Animais , Bicarbonatos , Carbonato de Cálcio , Carbono , Dióxido de Carbono , Equinodermos , Ecologia , Concentração de Íons de Hidrogênio , Oceanos e Mares
18.
Mar Pollut Bull ; 84(1-2): 424-36, 2014 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-24880682

RESUMO

Surface sediments from the coastal area of the Leizhou Peninsula in the South China Sea were collected and analyzed and the potential ecological risks in the area were assessed based on acid-volatile sulfide (AVS) model. The AVS levels are between 0.109 and 55.6 µmol g(-1), with the average at 4.45 µmol g(-1). The high AVS-concentration zones include the aquaculture areas of Liusha Bay and the densely populated areas of Zhanjiang Bay. The simultaneously extracted metals (SEM) range from 0.026 µmol g(-1) to 8.61 µmol g(-1), with the average at 0.843 µmol g(-1). Most of high SEM-concentration stations were located in ports or aquaculture zones. Most of the coastal surface sediments of the Leizhou Peninsula (90%) had no adverse biological effects according to the criterion proposed by USEPA (2005); while adverse effects were uncertain in some stations (8%); even in 2 stations (2%) adverse biological effects may be expected.


Assuntos
Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Poluentes Químicos da Água/química , Ácidos/análise , Aquicultura , Baías , China , Concentração de Íons de Hidrogênio , Metais/análise , Oceanos e Mares , Sulfetos/análise , Compostos Orgânicos Voláteis
19.
Environ Sci Pollut Res Int ; 21(16): 9931-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24756689

RESUMO

Quality improvement of acidic soil (with an initial pH of approximately 4.5) with respect to soil pH, exchangeable cations, organic matter content, and maize growth was attempted using natural (NSF) and calcined starfish (CSF). Acidic soil was amended with NSF and CSF in the range of 1 to 10 wt.% to improve soil pH, organic matter content, and exchangeable cations. Following the treatment, the soil pH was monitored for periods up to 3 months. The exchangeable cations were measured after 1 month of curing. After a curing period of 1 month, the maize growth experiment was performed with selected treated samples to evaluate the effectiveness of the treatment. The results show that 1 wt.% of NSF and CSF (700 and 900 °C) were required to increase the soil pH to a value higher than 7. In the case of CSF (900 °C), 1 wt.% was sufficient to increase the soil pH value to 9 due to the strong alkalinity in the treatment. No significant changes in soil pHs were observed after 7 days of curing and up to 3 months of curing. Upon treatment, the cation exchange capacity values significantly increased as compared to the untreated samples. The organic content of the samples increased upon NSF treatment, but it remains virtually unchanged upon CSF treatment. Maize growth was greater in the treated samples rather than the untreated samples, except for the samples treated with 1 and 3 wt.% CSF (900 °C), where maize growth was limited due to strong alkalinity. This indicates that the amelioration of acidic soil using natural and calcined starfish is beneficial for plant growth as long as the application rate does not produce alkaline conditions outside the optimal pH range for maize growth.


Assuntos
Agricultura/métodos , Solo/química , Estrelas-do-Mar/química , Resíduos/análise , Zea mays/crescimento & desenvolvimento , Ácidos/análise , Animais
20.
J Agric Food Chem ; 61(9): 2088-95, 2013 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-23373962

RESUMO

Two portable infrared sensors were evaluated for the rapid determination of quality parameters in processing tomatoes. A total of 370 hot-break juices were prepared from ∼40 processing tomato varieties grown in 5 California counties. The levels of sugars, acids, soluble solids, titratable acidity, and pH in these juices were determined using standard reference methods. Juices were processed, filtered, and directly applied to the FT-IR crystal (15-40 µL) to obtain spectra. Partial least-squares regression (PLSR) was used to generate correlation models, both calibration and validation. The PLS validation models showed good ability (Rval > 0.80; <10% SEP) in estimating the sugars, acids, and especially soluble solids in tomato for both the transmission DialPath portable system and benchtop unit using triple-bounce attenuated total reflectance (ATR). The IR portable unit may provide the tomato processing industry with an efficient method for in-plant, high throughput quantification of quality parameters in tomatoes.


Assuntos
Manipulação de Alimentos/métodos , Qualidade dos Alimentos , Solanum lycopersicum/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Ácidos/análise , California , Carboidratos/análise , Frutas/química , Concentração de Íons de Hidrogênio , Análise dos Mínimos Quadrados , Análise Multivariada , Espectroscopia de Infravermelho com Transformada de Fourier/instrumentação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA