Search results for "contamination"
showing 10 items of 916 documents
The dynamics of soil bacterial community structure in response to yearly repeated agricultural copper treatments
2008
International audience; The annual dynamics of soil bacterial community structure, including early, dose-dependent and transient modifications, was observed consecutively at different levels of copper contamination (high: 48 kg Cu ha−1, low: 16 kg Cu ha−1) repeated yearly over a three-year field experiment. Repeated low-level Cu contamination led to an increase in community stability to metal stress without a long-term shift in the population structure, whereas repeated high-level Cu contamination induced a novel and stable bacterial community structure. Furthermore, field experimentation highlighted that episodic climatic stress can modulate copper impact by enhancing community stability.
Horizontal distribution of copper, nickel and enchytraeid worms in polluted soil
1999
We studied the horizontal distribution of Cu, Ni and enchytraeid worms (Cognettia sphagnetorum, Vejdovsky, Oligochaeta, Enchytraeidae) in forest soil near a Cu–Ni smelter in SW Finland. Soil samples were taken from a polluted site (2 km from the smelter) and a reference area (8 km from the smelter). We used a hierarchical sampling design in the polluted area for studying possible scale-dependent variability in parameters measured, distance between the samples (different scales) being 5, 50 and 500 cm. Distribution of metals was moderately heterogeneous in the polluted soil; coefficient of variances (CV), 26% for Cu and 32% for Ni. Instead, distribution of enchytraeids in the area was highly…
Determination of organophosphate flame retardants in soil and fish using ultrasound-assisted extraction, solid-phase clean-up, and liquid chromatogra…
2017
A solid–liquid extraction method in combination with high‐performance liquid chromatography and tandem mass spectrometry was developed and optimized for extraction and analysis of organophosphorus flame retardants in soil and fish. Methanol was chosen as the optimum extraction solvent, not only in terms of extraction efficiency, but also for its broader analyte coverage. The subsequent clean‐up by solid‐phase extraction is required to eliminate matrix coextractives and reduce matrix effects. Recoveries of the optimized method were 50–121% for soil and 47–123% for biota, both with high precision (RSDs <12% in soil and <23% in biota). The method limits of detection ranged from 0.06 to 0.20 ng…
Current trends in solid-phase-based extraction techniques for the determination of pesticides in food and environment
2006
Solid-phase extraction (SPE) procedures for pesticide residues in food and environment are reviewed and discussed. The use of these procedures, which include several approaches such as: matrix solid-phase dispersion (MSPD), solid-phase micro-extraction (SPME) and stir-bar sorptive extraction (SBSE), represents an opportunity to reduce analysis time, solvent consumption, and overall cost. SPE techniques differ from solvent extraction depending on the interactions between a sorbent and the pesticide. This interaction may be specific for a particular pesticide, as in the interaction with an immunosorbent, or non-specific, as in the way a number of different pesticides are adsorbed on apolar or…
Pesticide analysis in coffee leaves using a quick, easy, cheap, effective, rugged and safe approach and liquid chromatography tandem mass spectrometr…
2017
An analytical method using a quick, easy, cheap, effective, rugged and safe (QuEChERS) procedure for multi-residue determination of 52 pesticides in coffee leaf extractshas been developed and validated according to SANTE/11945/2015 guidelines. Different sorbent combinations for dispersive solid phase extraction (d-SPE) clean-up as well as dispersive liquid-liquid microextraction (DLLME) were tested. The relative standard deviations (RSDs) for the recovery of 87-94% of pesticides added to coffee leaf extracts,was ≤20% for samples spiked at concentrations up to 50ng*g-1 depending on the clean-up procedures. However, samples spiked with a 100ng*g-1 pesticide mixture gave RSDs>20% for most pest…
Sustainable soy protein microsponges for efficient removal of lead (II) from aqueous environments
2023
Protein-based materials recently emerged as good candidates for water cleaning applications, due to the large availability of the constituent material, their biocompatibility and the ease of preparation. In this work, new adsorbent biomaterials were created from Soy Protein Isolate (SPI) in aqueous solution using a simple environmentally friendly procedure. Protein microsponge-like structures were produced and characterized by means of spectroscopy and fluorescence microscopy methods. The efficiency of these structures in removing Pb2+ ions from aqueous solutions was evaluated by investigating the adsorption mechanisms. The molecular structure and, consequently, the physico-chemical propert…
Spaces of cultural contamination. Creative places of sociality, integration, inclusion
2023
The well-being of the person is closely linked to the spaces in which they live and the resources they access. The recent slogan and urban paradigm "happy city and healthy city" bring attention back to the person and investigates the role of the built environment, individual, social and cultural well-being, as indicated in the sustainable development objectives of the 2030 Agenda. However, combining the city with the health and well-being of citizens requires an overall vision. It is necessary to graft a plot that can create - through resilient planning - interconnected and engaging open spaces, open and multiform specialized areas and, at the same time, incorporate pre-existing places and …
Mycotoxin Identification and In Silico Toxicity Assessment Prediction in Atlantic Salmon
2020
The present study aimed to identify mycotoxins in edible tissues of Atlantic salmon (Salmo salar) using liquid chromatography coupled to hybrid quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS). After using a non-targeted screening approach and a home-made spectral library, 233 mycotoxins were analyzed. Moreover, the occurrence of mycotoxins in fish filets was evaluated, and their potential toxicity was predicted by in silico methods. According to the obtained results, forty mycotoxins were identified in analyzed salmon samples, the predominant mycotoxins being enniatins (also rugulosin and 17 ophiobolins), commonly found in cereals and their by-products. Thus, mycotoxin carry-over …
Development and Validation of a LC-ESI-MS/MS Method for the Determination of Alternaria Toxins Alternariol, Alternariol Methyl-Ether and Tentoxin in …
2016
Alternaria species are capable of producing several secondary toxic metabolites in infected plants and in agricultural commodities, which play important roles in food safety. Alternaria alternata turn out to be the most frequent fungal species invading tomatoes. Alternariol (AOH), alternariol monomethyl ether (AME), and tentoxin (TEN) are some of the main Alternaria mycotoxins that can be found as contaminants in food. In this work, an analytical method based on liquid chromatography (LC) tandem mass spectrometry (MS/MS) detection for the simultaneous quantification of AOH, AME, and TEN in tomato and tomato-based products was developed. Mycotoxin analysis was performed by dispersive liquid-…
Determination of acrylamide in foods by pressurized fluid extraction and liquid chromatography-tandem mass spectrometry used for a survey of Spanish …
2006
An automated and rapid method for the determination of acrylamide in different food products is presented. The method involves pressurized fluid extraction (PFE) of foods with acetonitrile and precipitation with Carrez reagents. The final extract is analysed by liquid chromatography coupled to electrospray ionization tandem mass spectrometry (ESI-MS-MS). The main parameters affecting the performance of ESI-MS-MS and PFE were optimized using a design of experiments approach. The limit of quantification of the method was 5 microg kg(-1), and recoveries from incurred samples ranged between 93 and 101%. The accuracy was evaluated using the reference test materials FAPAS T3002, T3005 and T3011. …