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1.
Food Chem ; 215: 165-70, 2017 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-27542463

RESUMEN

Grain drying using firewood as fuel for air heating, with direct fire, is still widely used in Brazil. The combustion of organic material, such as wood, can generate polycyclic aromatic hydrocarbons (PAHs) which are known to have carcinogenic potential. In the present work corn grain drying was carried out at three drying air temperatures: 60°C, 60/80°C and 80°C. Following the drying process, the presence and quantification of PAH in the corn grains was investigated. After extracting the PAHs of the matrix, the material was subjected to analysis by gas chromatography with mass detector. he results showed the presence of seven compounds: fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)anthracene and chrysene.


Asunto(s)
Contaminación Ambiental , Hidrocarburos Policíclicos Aromáticos/análisis , Madera/química , Zea mays/química , Biomasa , Brasil , Carcinógenos/análisis , Contaminación Ambiental/legislación & jurisprudencia , Incendios
2.
Anal Chem ; 86(11): 5579-86, 2014 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-24796379

RESUMEN

Four previously unreported metabolism products of sulfaquinoxaline (SQX), a widely used veterinary medicine, were isolated and analyzed using liquid chromatography coupled to high-resolution Orbitrap mass spectrometry. Metabolites were structurally elucidated, and a fragmentation pathway was proposed. The combination of high-resolution MS(2) spectra, linear ion trap MS(2), in-source collision-induced dissociation (CID) fragmentation, and photolysis were used to analyze SQX and its metabolites. All metabolism products identified showed a similar fragmentation pattern to that of the original drug. Differential product ions were produced at m/z 162 and 253 which contain the radical moiety with more 16 Da units than sulfaquinoxaline. This occurs by a hydroxyl attachment to the quinoxaline moiety. With the exception of two low-intensity compounds, all the mass errors were below 5.0 ppm. The distribution of these metabolites in some animal species are also presented and discussed.


Asunto(s)
Sulfaquinoxalina/química , Animales , Biotransformación , Bovinos , Cromatografía Líquida de Alta Presión , Radical Hidroxilo/química , Hidroxilación , Indicadores y Reactivos , Hígado/química , Espectrometría de Masas , Aves de Corral , Ovinos , Sulfaquinoxalina/metabolismo , Distribución Tisular
3.
Artículo en Inglés | MEDLINE | ID: mdl-24195474

RESUMEN

Validation is a required process for analytical methods. However, scope extension, i.e. inclusion of more analytes, other matrices and/or minor changes in extraction procedures, can be achieved without a full validation protocol, which requires time and is laborious to the laboratory. This paper presents a simple and rugged protocol for validation in the case of extension of scope. Based on a previously reported method for analysis of sulfonamide residues using LC-MS/MS, inclusion of more analytes, metabolites, matrices and optimisation for the extraction procedure are presented in detail. Initially, the method was applied only to liver samples. In this work, milk, eggs and feed were also added to the scope. Several case-specific validation protocols are proposed for extension of scope.


Asunto(s)
Residuos de Medicamentos/análisis , Contaminación de Alimentos/análisis , Sulfonamidas/análisis , Alimentación Animal/análisis , Animales , Antibacterianos/análisis , Cromatografía Liquida , Huevos/análisis , Inocuidad de los Alimentos , Análisis de Peligros y Puntos de Control Críticos/métodos , Humanos , Hígado/química , Leche/química , Espectrometría de Masas en Tándem , Drogas Veterinarias/análisis
4.
Ciênc. rural ; Ciênc. rural (Online);42(12): 2265-2271, dez. 2012. tab
Artículo en Portugués | LILACS | ID: lil-658043

RESUMEN

Durante o armazenamento, pode ocorrer a perda de compostos voláteis responsáveis pelo aroma e o aumento de compostos indesejáveis, o que ocasiona a perda de qualidade do morango, reduzindo a vida de prateleira e levando à rejeição do produto pelos consumidores. Neste trabalho, foi avaliada a influência do sistema de produção (convencional e orgânico) e do período de armazenamento (0, 2, 5, 8 dias) nas características físicas e químicas (CFQ) e nos compostos voláteis (CV) de morango das cultivares 'Camarosa' e 'Camino Real', utilizando morangos de pomar comercial da região de Pelotas/RS. Os frutos foram colhidos em estádio de maturação comercial e com boa aparência. O planejamento experimental foi casualizado, em triplicata de 15 frutos. Os morangos foram armazenados a T de 1°C, com 90-95% umidade relativa (UR). Foram avaliadas a perda de massa, a coloração instrumental [L*, a*, b* e ângulo hue (H)] , a firmeza, os sólidos solúveis (SS), a acidez titulável (AT), a relação SS/AT, pH e os teores de CV. Os resultados foram submetidos à análise de variância e as diferenças significativas determinadas pelo teste de Tukey (P<0,05). Os resultados revelaram que pH, SS, relação SS/AT, podridões e perda de massa aumentaram durante o armazenamento. A firmeza se manteve irregular e a AT e H diminuíram significativamente. Os teores de CV aumentaram com exceção do acetato de metila (AM). O etanol (Et), o acetaldeído (AA) e o acetato de etila (AE) correlacionaram-se positivamente com o teor de podridões para a cultivar 'Camino Real' do cultivo orgânico. De modo geral o AM correlacionou-se inversamente com o teor de podridões, exceto para a cultivar 'Camino Real' do cultivo convencional. Os morangos de ambas as cultivares podem ser armazenados por cinco dias com qualidade, independente do sistema de produção.


During the storage a loss of volatile compounds responsible for the aroma and an increase of undesirable compounds can occur leading to a decrease in the strawberry quality, a reduction of the shelf life and product rejection by the consumers. In the present work the influence of the planting system (conventional and organic) and the storage period (0, 2, 5 and 8 days) upon physical and chemical characteristics (FCC) as well as on strawberry volatile compounds (VC) in the cultivars 'Camarosa' and 'Camino Real' were evaluated using strawberries from a commercial orchard from Pelotas/RS. The fruits were harvested in a stage of commercial maturation and sound appearance. The experimental planning was randomized, in triplicate of fifteen fruits. The strawberries were stored at 1°C and 90-95% of relative humidity (RH). The mass loss, the instrumental color [L*, a*, b* and hue angle (H)], the firmness, the soluble solids (SS), the titratable acidity (TA), the SS/TA ratio, the pH and VC content were determined. The results were analyzed by analysis of variance and significant differences were determined using Tukey's test (P<0.05). The results show that pH, SS, relation SS/TA, decay and mass loss have increased during storage. The firmness varied irregularly and TA and H decreased significantly. The values of VC increased with the exception of methyl acetate (MA). Ethanol (Et), acetaldehyde (AA) and ethyl acetate (EA) correlated positively with decay for organic cultivated 'Camino Real'. In a general way, the MA correlated inversely with decay with the exception of conventional cultivated 'Camino Real'. Strawberries from both cultures can be stored for five days without loosing quality regardless the production system.

5.
Cell Biochem Funct ; 28(5): 360-6, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20589733

RESUMEN

Type 2 diabetes (T2D) is associated with increased oxidative stress as indicated by elevated levels of lipid peroxidation and protein oxidation products. Since reactive oxygen species (ROS) can cause damage to biological macromolecules including DNA, this study investigated oxidative damage to DNA using the alkaline (pH > 13) comet assay in peripheral whole blood leukocytes sampled from 15 dyslipidemic T2D patients treated with simvastatin (20 mg/day), 15 dyslipidemic T2D patients not treated with simvastatin, 20 non-dyslipidemic T2D patients, and 20 healthy individuals (controls). Our results showed a greater DNA migration in terms of damage index (DI) (p < 0.01) in the dyslipidemic T2D patients not treated with statin (DI = 67.70 +/- 10.89) when compared to the dyslipidemic T2D patients under statin treatment (DI = 47.56 +/- 7.02), non-dyslipidemic T2D patients (DI = 52.25 +/- 9.14), and controls (DI = 13.20 +/- 6.40). Plasma malondialdehyde (MDA) and C-reactive protein (CRP) levels were also increased and total antioxidant reactivity (TAR) and paraoxonase activity (PON1) decreased in non-dyslipidemic T2D patients and dyslipidemic T2D non-treated with simvastatin. We also found that DI was inversely correlated with TAR (r = -0.61, p < 0.05) and PON1 (r = -0.67, p < 0.01). In addition, there was a significant positive correlation between DI and CRP (r = 0.80, p < 0.01). Our results therefore indicate that simvastatin treatment plays a protective role on oxidative damage to DNA in dyslipidemic T2D patients probably reflecting a general decrease in oxidative stress in these patients.


Asunto(s)
Diabetes Mellitus Tipo 2/complicaciones , Dislipidemias/tratamiento farmacológico , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Leucocitos/efectos de los fármacos , Estrés Oxidativo , Simvastatina/uso terapéutico , Adulto , Anciano , Arildialquilfosfatasa/sangre , Proteína C-Reactiva/análisis , Ensayo Cometa , Daño del ADN , Dislipidemias/complicaciones , Femenino , Humanos , Leucocitos/inmunología , Leucocitos/metabolismo , Masculino , Malondialdehído/sangre , Persona de Mediana Edad
6.
Arch Med Res ; 41(2): 104-9, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20470939

RESUMEN

BACKGROUND AND AIMS: Oxidative stress is considered an important factor in the development of diabetic complications that causes a variety of changes such as oxidative modification of membrane lipids, nucleic acids and cellular proteins. Dyslipidemia is frequently associated with diabetes and cardiovascular disease. In this context, the objective of this study was to evaluate oxidative modifications of plasma proteins and lipids in non dyslipidemic type 2 diabetic (T2D) patients, in dyslipidemic T2D patients treated or not with simvastatin and in healthy subjects to investigate whether treatment with low doses of simvastatin plays a protective role on the lipid and protein oxidative damage in these patients. METHODS: We determined oxidative damage of plasma proteins by carbonyl assay and total thiol group determination. We also characterized the membrane damage in terms of lipid peroxidation by measuring malonaldehyde (MDA) in nondyslipidemic T2D patients, dyslipidemic T2D patients treated with simvastatin (20 mg/day), dyslipidemic T2D patients not treated with simvastatin and in healthy age-matched control subjects. RESULTS: Our results showed that dyslipidemic T2D patients not treated with simvastatin had significantly higher plasma protein carbonyl groups and MDA when compared to dyslipidemic T2D patients treated with simvastatin and control group. Thiol concentrations from dyslipidemic T2D patients not treated with simvastatin were significantly lower than treated patients and controls. It was verified that the thiols groups were inversely correlated with apolipoprotein B and positively correlated with apolipoprotein A-I. CONCLUSIONS: These results demonstrated that treatment with low doses of simvastatin can minimize the protein and lipid oxidative damage in dyslipidemic T2D patients.


Asunto(s)
Apolipoproteínas/metabolismo , Proteína C-Reactiva/metabolismo , Diabetes Mellitus Tipo 2 , Hipolipemiantes/uso terapéutico , Estrés Oxidativo , Simvastatina/uso terapéutico , Adulto , Anciano , Biomarcadores/metabolismo , Glucemia/metabolismo , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/fisiopatología , Femenino , Humanos , Peroxidación de Lípido , Masculino , Persona de Mediana Edad , Oxidación-Reducción , Carbonilación Proteica
7.
J Natl Med Assoc ; 100(8): 897-902, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18717139

RESUMEN

Sickle cell anemia (SCA) is a hereditary disorder with higher potential for oxidative damage due to chronic redox imbalance in red cells. We measured antioxidant enzymes including catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD). We also determined oxidative damage of proteins in hemolysate of red blood cells (RBCs) and plasma (carbonyl assay). We characterized the membrane damage in terms of lipid peroxidation by accumulation of malonaldehyde (MDA) by HPLC in 30 healthy controls and 20 SCA patients in steady-state condition. Twenty (9 males/11 females) adult SCA patients and 30 healthy controls were studied. All patients and control subjects had antioxidant (CAT, GPx, SOD, carbonyl and MDA) and hematological parameters done. Our data show that SCA patients had significant higher GPx and SOD activities than healthy controls. Carbonyl assay was noted in plasma but not in hemolysate. An enhanced production of MDA was observed in the serum of SCA patients. Our data support the growing evidence that patients with SCA are subjected to chronic oxidative stress and are able to oxidative damage in biological macromolecules such as proteins and lipids.


Asunto(s)
Anemia de Células Falciformes/enzimología , Antioxidantes/metabolismo , Catalasa/sangre , Glutatión Peroxidasa/sangre , Superóxido Dismutasa/sangre , Adulto , Estudios de Casos y Controles , Cromatografía Líquida de Alta Presión , Femenino , Humanos , Peroxidación de Lípido , Masculino , Malondialdehído/metabolismo
8.
Artículo en Inglés | MEDLINE | ID: mdl-17365308

RESUMEN

Regular (non-alkylated) polycyclic aromatic hydrocarbons (PAHs) and their alkylated homologues were determined in sediments from Rodrigo de Freitas Lagoon using gas chromatography with mass selective detector (GC-MSD). Concentrations varying from 405 to 11734 ng x g(-1) were found for total PAHs (regular and alkylated homologues). The study showed a pyrogenic and petrogenic contribution, probably due to the incomplete burning of fossil fuels as a result of the intense traffic of boats and motor vehicles added to the anthropogenic activity of several gas stations present in the region of Rodrigo de Freitas Lagoon. According to the National Oceanic and Atmospheric Administration (NOAA) Sediment Quality Guide, PAHs concentration should not exceed 4000 ng x g(-1) (Long et al., 1995) The obtained data present values above the NOAA limit for some sampling points indicating chronic contamination of those sites probably due to anthropogenic activities related to petroleum and its derivatives.


Asunto(s)
Sedimentos Geológicos/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes Químicos del Agua/análisis , Brasil , Ciudades , Monitoreo del Ambiente , Combustibles Fósiles , Emisiones de Vehículos
9.
Artículo en Inglés | MEDLINE | ID: mdl-17018416

RESUMEN

The work described in this paper presents an evaluation of disinfection by-products generation in four different biological treatment plant effluents, making use of sodium hypochlorite and sodium ferrate (IV) at varying concentration and reaction time. Correlations between pH, chemical oxygen demand, total organic carbon, ammonium nitrogen, combined chlorine and trihalomethanes (THMs) and haloacetic acids (HAAs) were carried out. Disinfection by-products generation presented a direct relation with concentration and sodium hypochlorite reaction time. For the highest hypochlorite concentration employed (20 mg L(-1)) and highest reaction time (168 h), the THMs total did not exceed 312.96 microg L(-1), a value that lies below the Brazilian emission standard for treated effluents (1 mg L(-1) of chloroform). The THMs presented an inverse correlation with ammonium nitrogen, when inverse (R(2) = 0.646; P < 0.001) and exponential (R(2) = 0.707; P < 0.001) function were used. As per HAAs this same relation was observed for logarithmic (R(2) = 0.0397 P < 0.001) and exponential (R(2) = 0.508; P < 0.001) functions. The more nitrified the effluent, the bigger the chlorinated disinfection by-product generation. The disinfectant sodium ferrate (IV) does not lead to halogenated by-product formation.


Asunto(s)
Acetatos/análisis , Desinfectantes/química , Hierro/química , Compuestos de Amonio Cuaternario/química , Hipoclorito de Sodio/química , Sodio/química , Trihalometanos/análisis , Contaminantes Químicos del Agua/análisis , Brasil , Interpretación Estadística de Datos , Estudios de Evaluación como Asunto , Residuos Industriales , Compuestos de Amonio Cuaternario/análisis , Aguas del Alcantarillado , Factores de Tiempo , Eliminación de Residuos Líquidos , Contaminantes Químicos del Agua/química , Purificación del Agua/métodos
10.
Artículo en Inglés | MEDLINE | ID: mdl-16760087

RESUMEN

Identification and quantification of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in fly ashes from incinerator was carried out using capillary gas chromatography/tandem mass spectrometry (GC/MS/MS) with a low resolution ion trap mass spectrometer. Sample extraction was carried out in a cellular disruptor, in Soxhlet and in a conventional ultrasound for comparative purposes. Extraction with cellular disruptor was shown to be comparable to that obtained by the reference Soxhlet extraction, while low recoveries were observed with ultrasound. Hospital incinerator ashes, extracted by cellular disruptor and Soxhlet presented I-TEQ values for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans of 370 +/- 81 ng g(-1) and 533 +/- 55 ng g(-1), respectively, statistically equivalent according to the t-test.


Asunto(s)
Contaminantes Atmosféricos/análisis , Benzofuranos/análisis , Carbono/análisis , Monitoreo del Ambiente/métodos , Dibenzodioxinas Policloradas/análogos & derivados , Ceniza del Carbón , Dibenzofuranos Policlorados , Monitoreo del Ambiente/instrumentación , Cromatografía de Gases y Espectrometría de Masas , Incineración , Residuos Industriales , Material Particulado , Dibenzodioxinas Policloradas/análisis , Ultrasonido
11.
J Colloid Interface Sci ; 288(1): 45-54, 2005 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-15927560

RESUMEN

Silica (350 m(2) g(-1)) was chemically modified with Cp2ZrCl2 and (nBuCp)2ZrCl2 by grafting. Hybrid silica bearing surface indene groups was synthesized by the sol-gel method, followed by metallation with ZrCl(4)2THF. The resulting phases were characterized by Rutherford backscattering spectrometry (RBS), 13C and 29Si magic angle spin nuclear magnetic resonance, X-ray photoelectron spectroscopy, and diffuse reflectance infrared Fourier transform spectroscopy. According to RBS measurements, metal content was 0.2- to 0.3-wt% Zr/SiO2 for the grafted systems and 4.5-wt% Zr/SiO2 for the phase prepared by the sol-gel method. The solid phases were evaluated for the adsorption/preconcentration of lindane and heptachlor epoxide from aqueous solution. For comparative reasons, the commercial LC-18 phase was also evaluated. Analyte concentration was monitored by gas chromatography electron capture detection. For the grafted phases, the coordination sphere around the metal center seems not to influence the adsorption/desorption properties of these phases vis-a-vis the studied analytes. In the case of the phases prepared by the sol-gel method, recovery results were comparable to those observed for LC-18. Experiments using ZrO2 and ZrO2/SiO2 phases led to lower recovery results.

12.
Pesticidas ; 12: 145-154, jan.-dez. 2002. graf
Artículo en Portugués | LILACS | ID: lil-357783

RESUMEN

Monitorou-se a presença do herbicida Glifosato e do seu metabólito, ácido aminometilfosfônico (AMPA), em amostrasde águas coletadas em área orizícola, submetida a plantio direto. Níveis de Glifosato em concentraçöes acima do limite máximo permitido (7,0 ug/L) pela Agência de Proteçäo Ambiental dos Estados Unidos (Environmental Protection Agency) foram detectados. A presença do metabólito AMPA, nas águas dos canais de irrigaçäo, foi detectada até 120 dias após a aplicaçäo (DAA). Pode-se dizer que determinado nível de segurança será alcançado nas águas de lançamento da granja para o Arroio Bretanhas, 120 DAA da formulaçäode Glifosato. Como näo foi observada deserçäo do Glifosato em Gleyssolo Haplico Ta Eutrófico pode-se inferir que a concentraçäo do mesmo permaneceu como resíduo ligado. Assim, a dissipaçäo do herbicida nesse solo pode ser reflexo, entre outros fatores, da formaçäo de resíduo ligado, determinando desta forma o seu destino e/ou comportamento no ambiente.


Asunto(s)
Monitoreo del Ambiente , Herbicidas , Oryza , Agua
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