Formaldehyde and total aldehydes in indoor air of public environments by voltammetry

The proposed method involves active sampling, where a sampling pump is used to pull air through a solution and voltammetric analysis of the obtained solutions. No interferences have been observed. In addition, very little sample preparation is required. Analyses were performed in 19 indoor stations and one in outdoor. Measurements were carried out on University environments: Museum of Chemistry, Zoological Museum, libraries, laboratories, corridors, meeting rooms, photocopying room, machine shop and terrace. Formaldehyde concentrations in analyzed samples ranged from 2.6 to 85 μg m-3 (median = 32 μg m-3), while the sum of others aldehydes ranged from 2 to 25 μg m-3 (median =2.4 μg m-3). In the sample Zoological Museum 2, the sum of other aldehydes was very high (400 μg m-3). The results demonstrated that artificial ventilation is an efficient system to control indoor air pollution caused by aldehydes emissions

Photochemical sample treatment for extracts clean up in PCB analysis from sediments

Sample purification can be considered the most polluting step of the whole analytical process for PCBs determination in sediment samples. The use of photochemical sample treatment represents an alternative methodology for extracts clean up allowing for a reduction of the used amount of organic solvents. The first application of a photochemical sample treatment for the selective removal or reduction of organic substances interfering with PCBs analyses in sediments is reported. The method's efficiency and robustness were compared with currently used chromatographic purification. Quality parameters such as recovery, linearity and reproducibility were studied. The entire procedure was validated by four replicate analysis of certified reference sediment. The quantification limits (LOQ) obtained by us ranged from 1 to 3.1 ng g(-1). The RSD for each congener was below 15\% and recoveries were in the range 40-130\%. Results based on the analysis of real and certified samples showed similar or improved detection thresholds and pointed out the advantages of the photochemical methodology in terms of costs and environmental friendly conditions. (C) 2012 Elsevier B.V. All rights reserved

The effect of montmorillonite clay in alginate gel beads for polychlorinated biphenyl adsorption: Isothermal and kinetic studies

Beads of alginate montmorillonite have been used as sorbent for polychlorinated biphenyls from aqueous solutions.The structure and the differences between the different beads were established by IR spectroscopy (FT-IR). The adsorption at 25 °C has been studied in a batch system, following its kinetics and assessing adsorbent dose, initial PCB concentrations, and pH effects. The results show that increasing the initial concentration of the PCBs and the adsorption time favored the adsorption. Adsorption isotherm data were modeled using Chapman, Freundlich and Langmuir adsorption isotherms and the appropriate parameters were calculated.Adsorption of trichlorobiphenyls on alginate–montmorillonite beads followed a Freundlich isotherm type model, while adsorption of tetra-, penta-, and hexachlorobiphenyls displayed a sigmoid-shaped (S-type) isotherm fitting the Chapman sigmoidal equation with the highest non-linear R2 values among the three tested models. By comparing the percentage adsorptions using the same number of beads (same volumes), best removals were obtained by using alginate montmorillonite beads.Adsorption of trichlorobiphenyls on alginate–montmorillonite beads followed a Freundlich isotherm type model, while adsorption of tetra-, penta-, and hexachlorobiphenyls displayed a sigmoid-shaped (S-type) isotherm fitting the Chapman sigmoidal equation with the highest non-linear R2 values among the three tested models. By comparing the percentage adsorptions using the same number of beads (same volumes), best removals were obtained by using alginate montmorillonite beads.Adsorption of trichlorobiphenyls on alginate–montmorillonite beads followed a Freundlich isotherm type model, while adsorption of tetra-, penta-, and hexachlorobiphenyls displayed a sigmoid-shaped (S-type) isotherm fitting the Chapman sigmoidal equation with the highest non-linear R2 values among the three tested models. By comparing the percentage adsorptions using the same number of beads (same volumes), best removals were obtained by using alginate montmorillonite beads.Adsorption of trichlorobiphenyls on alginate–montmorillonite beads followed a Freundlich isotherm type model, while adsorption of tetra-, penta-, and hexachlorobiphenyls displayed a sigmoid-shaped (S-type) isotherm fitting the Chapman sigmoidal equation with the highest non-linear R2 values among the three tested models. By comparing the percentage adsorptions using the same number of beads (same volumes), best removals were obtained by using alginate montmorillonite beads. Kinetic models were investigated to determine the mechanism of adsorption showing a best fit for the pseudo second order model (R2 from 0.998 to 0.982. Moreover, to underline the effect of montmorillonite in alginate gel beads, we have compared the isothermal adsorption curves between alginate montmorillonite and alginate beads

Flavouring extra-virgin olive oil with aromatic and medicinal plants essential oils stabilizes oleic acid composition during photo-oxidative stress

Essential oils (EOs) from medicinal and aromatic plants (MAPs) are well-known as natural antioxidants. Their addition to extra-virgin olive oil (EVOO) can contribute to reducing fat oxidation. The main aim of this study was to improve both food shelf-life and aromatic flavour of EVOO, adding different EOs of Sicilian accessions of common sage, oregano, rosemary and thyme. The morphological and production characteristics of 40 accessions of MAPs were preliminarily assessed. EOs from the most promising accessions of MAPs were analysed by gas-chromatography and mass spectrometry. Photo-oxidative studies of the EOs were carried out and the determination of the EVOO fatty acids obtained from 4 Italian olive varieties was also made. EO content was on average 1.45% (v/w) for common sage, 3.97% for oregano, 1.42% for rosemary and 5.90% for thyme accessions. The highest average EO yield was found in thyme (172.70 kg ha1) whilst the lowest (9.30 kg ha1) in rosemary accessions. The chemical composition of EOs was very different in the four MAPs in the study. No significant change of oleic acid percentage was detected in the mixture of EVOO with EO samples. The results seem to highlight the presence of an antioxidant effect of EOs on EVOO

Improving building energy modelling by applying advanced 3D surveying techniques on agri-food facilities

Food industry is the production sector with the highest energy consumption. In Europe, the energy used to produce food accounts for 26% of total energy consumption. Over 28% is used in industrial processes. Recently, European food companies have increased their efforts to make their production processes more sustainable, also by giving preference to the use of renewable energy sources. In Italy, the total energy consumption in agriculture and food sectors decreased between 2013 and 2014, passing from 16.79 to 13.3 Mtep. Since energy consumption in food industry is nearly twice the one in agriculture (8.57 and 4.73 Mtep, respectively), it is very important to improve energy efficiency and use green technologies in all the phases of food processing and conservation. In Italy, a recent law (Legislative Decree 102, 04/07/2014) has made energy-use diagnosis compulsory for all industrial concerns, particularly for those showing high consumption levels. In the case of food industry buildings, energy is mainly used for indoor microclimate control, which is needed to ensure workers' wellbeing and the most favourable conditions for food processing and conservation. To this end, it is important to have tools and methods allowing for easy, rapid and precise energy performance assessment of agri-food buildings. The accuracy of the results obtainable from the currently available computational models depends on the grade of detail and information used in constructional and geometric modelling. Moreover, this phase is probably the most critical and time-consuming in the energy diagnosis. In this context, fine surveying and advanced 3D geometric modelling procedures can facilitate building modelling and allow technicians and professionals in the agri-food sector to use highly efficient and accurate energy analysis and evaluation models. This paper proposes a dedicated model for energy performance assessment in agri-food buildings. It also shows that using advanced surveying techniques, such as a terrestrial laser scanner and an infrared camera, it is possible to create a three-dimensional parametric model, while, thanks to the heat flow meter Accepted paper measurement method, it is also possible to obtain a thermophysical model. This model allows assessing the energy performance of agri-food buildings in order to improve the indoor microclimate control and the conditions of food processing and conservation

N-TiO2-x Nanocatalysts: PLAL Synthesis and Photocatalytic Activity

N-TiO2-x nanocatalysts are developed by the pulsed laser ablation in liquid (PLAL) technique, a simple and surfactant-free preparation method. The PLAL approach allows synthesizing chemical-morphological fine-tuning water TiO2-based nanomaterials, starting from targets of different nature (powders and commercial high purity targets). The catalytic activity was investigated using methylene blue (cationic dye) and methyl orange (azo dye). A different photocatalytic response was found for the various kinds of N-TiO2-x. In the first 20 min, under UV and visible light, about 50% and 10% of the methyl orange were removed using the N-TiO2-x and TiO2 colloids, respectively. In addition, we observe that the response towards the methylene blue is comparable in all the synthesized samples under UV irradiation while differing by about 30% under a visible lamp. The enhanced photocatalytic response of the N-TiO2-x nanocatalysts with respect to the TiO2 one is dependent on the content of the nitrogen dopant, surface area, and nitrogen-oxygen bonding configurations

Structural Modifications of the Quinolin-4-yloxy Core to Obtain New Staphylococcus aureus NorA Inhibitors

: Tackling antimicrobial resistance (AMR) represents a social responsibility aimed at renewing the antimicrobial armamentarium and identifying novel therapeutical approaches. Among the possible strategies, efflux pumps inhibition offers the advantage to contrast the resistance against all drugs which can be extruded. Efflux pump inhibitors (EPIs) are molecules devoid of any antimicrobial activity, but synergizing with pumps-substrate antibiotics. Herein, we performed an in silico scaffold hopping approach starting from quinolin-4-yloxy-based Staphylococcus aureus NorA EPIs by using previously built pharmacophore models for NorA inhibition activity. Four scaffolds were identified, synthesized, and modified with appropriate substituents to obtain new compounds, that were evaluated for their ability to inhibit NorA and synergize with the fluoroquinolone ciprofloxacin against resistant S. aureus strains. The two quinoline-4-carboxamide derivatives 3a and 3b showed the best results being synergic (4-fold MIC reduction) with ciprofloxacin at concentrations as low as 3.13 and 1.56 µg/mL, respectively, which were nontoxic for human THP-1 and A549 cells. The NorA inhibition was confirmed by SA-1199B ethidium bromide efflux and checkerboard assays against the isogenic pair SA-K2378 (norA++)/SA-K1902 (norA-). These in vitro results indicate the two compounds as valuable structures for designing novel S. aureus NorA inhibitors to be used in association with fluoroquinolones