ABSTRACT In order to identify the levels of contamination of mangrove soils by polycyclic aromatic hydrocarbons (PAH), their concentration was determined by gas chromatography coupled to mass spectrometry in the fraction of aromatic hydrocarbons obtained from soluble organic matter (SOM). Soils are located in Cuare Inlet and Morrocoy National Park from Venezuela, and samples were collected in Punta La Matica (PLM) and Tucacas Bay (ETU) respectively. Naphthalene, acenaphthene, acenaphthalene, benzo(ghi)perylene, dibenzo(ah)anthracene and indene have concentrations lower than the detection threshold for the technique employed (≤ 20 ng/g). Fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)anthracene, chrysene, benzo(k)fluoranthene, benzo(b)fluoranthene and benzo(a)pyrene present concentrations ranging from 24 to 967 ng/g, and in some cases were not detected (≤ 20 ng/g). The PAHs concentration are classified in a pollution level from moderate to high in ETU and low in PLM. These results indicate a major anthropogenic pollution level of soils from ETU in relation to PLM soils. Based on the fact that the PAHs detected are not substituted and dominate the 3- and 4-rings, three diagnostic ratios to identify the contamination source were calculated: [anthracene/(anthracene+phenanthrene), fluoranthene/(fluoranthene+pyrene); and benzo(a)anthracene/(benzo(a)anthracene+chrysene)]; these ratios suggest a source from combustion of organic matter. Additionally, the normalization of total PAHs related to total organic carbon (TOC) or SOM represents a linear relationship between total PAHs with PAH/TOC and PAH/SOM, and suggests that the PAHs detected are from the same source, that is, the combustion of organic matter from anthropogenic activity or natural fires.

RESUMEN Para identificar los niveles de contaminación de suelos de manglares por hidrocarburos aromáticos policíclicos (HAP), se determinó su concentración por cromatografía de gases acoplada a espectrometría de masas en la fracción de hidrocarburos aromáticos obtenida de la materia orgánica soluble (MOS). Los suelos están ubicados en el golfete de Cuare y el Parque Nacional Morrocoy, Venezuela y fueron recolectados en la Bahía de Tucacas (ETU) y Punta La Matica (PLM). Naftaleno, acenaftaleno, acetanaftaleno, benzo(ghi)perileno, dibenzo(ah)antraceno e indeno, están en concentraciones por debajo del límite de detección de la técnica utilizada (≤ 20 ng/g). Fluoreno, fenantreno, antraceno, fluoranteno, pireno, benzo(a)antraceno, criseno, benzo(k)fluoranteno, benzo(b)fluoranteno y benzo(a)pireno presentan concentraciones entre 24 y 967 ng/g, y en algunos casos no fueron detectados (≤ 20 ng/g). La concentración de HAP en los sitios de muestreo los clasifica con niveles de contaminación de moderados a altos en ETU y bajos en PLM. Estos resultados indican un mayor nivel de contaminación en los suelos de ETU en comparación con los de PLM. Con base en que los HAP detectados son no sustituidos y dominan los de 3 y 4 anillos, se calcularon tres relaciones diagnósticas para la identificación de la fuente de contaminación: [antraceno/(antraceno+fenantreno), fluorantenoe/(fluoranteno+pireno) y benzo(a)antraceno/(benzo(a)antraceno+criseno)], que sugieren una fuente por combustión de materia orgánica. Adicionalmente, la normalización de los HAP respecto al carbono orgánico total (COT) y la materia orgánica soluble (SOM) sugiere una sola fuente a partir de la combustión de materia orgánica de actividad antrópica o combustión natural.

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.

This paper evaluates the adsorption capacity of zirconocene-based silica materials in the pre-concentration of antimicrobians (tetracycline, sulfamethoxazole and trimethoprim) in aqueous medium. These materials were prepared by grafting the zirconocene onto silicas pre-treated at different temperatures. The retention capacity of these materials was evaluated by off line SPE and HPLC-UV and the proposed methodology was validated in ultrapure, tap and river water. The recovery for tetracycline was 72% (in the solid phase A) and, for sulfamethoxazole and trimethoprim was 68 and 95% in the commercial C18, respectively. The target antimicrobians were not detected in the Arroio Dilúvio (Porto Alegre - RS).

Following application herbicides usually reach the soil and undergo several dissipation processes which determine their effects on target organisms and on the environment. This work aimed to evaluate atrazine and mesotrione sorption in Oxisols and estimate their potential impact on the environment. We observed that atrazine sorption was influenced by soil organic matter content and its hydrophobic character. Clay fraction was the main factor influencing mesotrione sorption followed in a lesser extent by soil organic matter content. In contrast to atrazine, mesotrione retention was favored by the higher carboxylic substitution in the aliphatic chains of soil organic matter. Atrazine and mesotrione were considered compounds that are likely to pose an appreciable risk of causing deleterious effects on the environment.