32 research outputs found
Measurement of squalene in olive oil by fractional crystallization or headspace solid phase microextraction coupled with gas chromatography
Squalene is the most abundant component in the unsaponifiable fraction of olive oil with strong antioxidant properties. Its concentration in olive oils varies between 0.2 and 16.2 g/kg depending on the cultivar(s) used. The propose of this work was to determine the effectiveness of two different extraction methods for squalene determination by gas chromatography (GC) coupled to a flame ionization detector (FID) or to mass spectrometry (MS). In a first approach, oil samples were dissolved in methanol/acetone mixture 7:3 (v/v) and triglycerides separated by fractional crystallization at â20°C. The organic layer was removed, reduced to dryness and the residue reconstituted in n-heptane (containing squalane as external standard) and analyzed by GC-FID. A headspace (HS) solid phase microextraction (SPME) GC-MS method has been also developed in order to have an environmentally friendly (i.e. solventless) extraction procedure. The linear range investigated with both methods was 1.0-10 g/kg. Within-day and between days precision values, expressed as RSD%, were 4 and 7% (GC-FID), and 3 and 6% (GC-MS), respectively. The limit of detection (LOD) at a signal-to-noise (S/N) ratio of 3 were 0.019 (GC-FID) and 0.003 (GC-MS) g/kg; the limit of quantification (LOQ) calculated at S/N = 10 were 0.063 (GC-FID) and 0.008 (GC-MS) g/kg, well below the typical squalene concentration levels found in olive oils. The obtained percentage recoveries were 70 ± 2 (GC-FID) and 98 ± 3 (GC-MS), and were not concentration dependent. The potential of the method has been demonstrated by the analysis of several different olive oil samples produced from different cultivars and different locations
Photocatalytic inactivation of Escherichia coli bacteria in water using low pressure plasma deposited TiO2 cellulose fabric
Fabrics obtained from cellulose spinning, extracted from Spanish broom, were coated with TiO2 film, through the low pressure plasma sputtering technique, in order to get antibacterial activity. The obtained fabrics were used for the photocatalytic degradation of Escherichia coli, by irradiation with UV-light emitting diodes (UV-LED), in a batch photocatalytic reactor. Before and after functionalization treatments, cellulosic substrates were chemically characterized by X-ray photoelectron spectroscopy (XPS) analyses. Water Contact Angle (WCA) measurements allowed obtaining information about the hydrophilicity of the materials, while their antibacterial efficiency was determined at several initial concentrations (from 103 up to 108 CFU mLâ1) of bacteria in distilled water, bottled water and synthetic wastewater. It was found that photocatalytic reactions were capable of achieving up to 100% bacterial inactivation in 1 h of treatment, following a pseudo-first order kinetic model. No bacterial regrowth was observed after photocatalytic treatments in almost all experimental conditions. In contrast, during photolytic treatment (i.e. in the absence of the TiO2 coated fabrics) bacteria recovered their initial concentration after 3 h in the dark. Finally, the reusability of the plasma modified fibers to inactivate bacteria was studied
Determination of Commercial Animal and Vegetable Milksâ Lipid Profile and Its Correlation with Cell Viability and Antioxidant Activity on Human Intestinal Caco-2 Cells
none9openantonella aresta; Stefania De Santis; Alessia Carocci; Alexia Barbarossa; Andrea Ragusa; Nicoletta De Vietro; Maria Lisa Clodoveo; Filomena Corbo; Carlo ZAMBONINAresta, Antonella; De Santis, Stefania; Carocci, Alessia; Barbarossa, Alexia; Ragusa, Andrea; De Vietro, Nicoletta; Lisa Clodoveo, Maria; Corbo, Filomena; Zambonin, Carl
HYDROPHILIC FLUOROCARBON COATINGS VIA PLASMA ENHANCED-CHEMICAL VAPOUR CO-DEPOSITION OF ACRYLIC ACID AND HEXAFLUOROPROPYLENE OXIDE
The co-deposition of acrylic acid and hexafluoropropylene oxide in pulsed plasmas
was studied with the purpose to obtain wettable fluorocarbon coatings containing
carboxylic acid groups, which are potentially useful for several employments, e.g.,
as proton-exchange membranes for electrochemical applications.
It was found that the hydrophilic fluorocarbon thin films with the higher
concentration of surface acidic groups can be obtained at lower duty cycle. After
one week of immersion in water at 80°C the trends are inverted, the concentration
of acidic groups and the wettability increase with the duty cycle
Introduction of Basic Functionalities on the Surface of Granular Adsorbers by Low Pressure Plasma Processes
Low pressure plasma, generated in a radio frequency reactor under rotation, was utilized to modify the ability of granular substrates to adsorb volatile acid compounds. Carbon black granules were treated with NH 3 or allylamine containing feeds, while sepiolite granules were processed only in allylamine fed discharges. The chemical modifications induced by plasma treatments were evaluated by means of X-ray photoelectron spectroscopy studies and water contact angle measurements, while scanning electron microscope and Brunauer, Emmet, Teller analyses were performed to study the surface morphological changes caused by plasma processes. The ability of the treated materials to adsorb acids, in gas or vapour phase, was estimated with hydrochloric, acetic and propanoic acid, employing a home-made test system. The results show that the optimized plasma treatments are able to improve the adsorption ability of carbon black and sepiolite granules for the three acids investigated. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Porous alumosilicate aggregate as lead ion sorbent in wastewater treatments
Porous alumosilicate aggregate, namely perlite, was used as an alternative material in wastewater treatments for the selective removal of ionic pollutants such as lead which is present in industrial wastewaters and toxic at relatively low concentrations. Metal retention was investigated by single metals and multispecies equilibrium isotherms (batch system) and by carrying out dynamic (column) experiments. Lead ions were supposedly preferentially retained by ion exchange at the negatively charged silicate functional groups present on the perlite material, and to a minor extent by weak electrostatic (Van der Waals) interactions at non-specific functionalities. In the case of the batch system, the Freundlich isotherm gave a good correlation of the experimental data and lead maximum retention (qmax) in single ion solution was 4.28 mg/gperlite, and in multimetal solution was 1.50 mg/gperlite. In the case of the column system, overall capacity was 3.7 mg/gperlite in single ion solution, and in multimetal solution was 3.0 mg/gperlite. In multimetal solutions, lead ions showed the best interaction at the perlite functional groups because of the lowest free energies of hydration and hydrated radius. After sorption, perlite beads were used as lightweight aggregates for cement mortars after evaluation of the potential release of lead ions from the conglomerates
Preparation of Multifunctional Superhydrophobic Nanocomposite Coatings Deposited by Aerosol-Assisted Atmospheric Cold Plasma Deposition
A general method for the preparation of superhydrophobic organic-inorganic nanocomposite
coatings by atmospheric pressure cold plasma is presented. The method consists of a singlestep
room-temperature aerosol-assisted deposition process in which the aerosol of a
dispersion of oleate-capped ZnO nanoparticles in liquid hydrocarbon precursors (i.e., a
mixture of n-octane and 1,7-octadiene) is injected in a dielectric barrier discharge. The
plasma-deposited hydrocarbon polymer/ZnO nanoparticles nanocomposite coatings show
multifunctional behavior and specifically combine the photocatalytic properties of ZnO with
superhydrophobicity; the latter results from the synergistic effect of the hierarchical
multiscale surface texture due to the incorporation of nanoparticles and the low surface
energy organic component formed via plasma polymerization of the hydrocarbon precursors
Low pressure plasma modified polycarbonate: a transparent, low reflective and scratch resistant material for automotive applications
In this paper, we report a two steps low pressure plasma treatment composed by an etching, optimized for the nano-texturing of polycarbonate to improve its anti-reflective property by simulating the so called âMoth eyeâ effect, and by a plasma enhanced-chemical vapour deposition process to enhance the scratch resistance.
Reflectance/transmittance measurements showed that this approach is able to increase the anti-reflective property of the polycarbonate without drastically damaging its transmittance, while scratching test by âcar washâ simulator demonstrated the increase of scrape resistance. The haze test confirmed the transparency of the plasma treated polymer also after washing
Plasma Treatment for Preparing Durable Water Repellent and Anti-Stain Synthetic Fabrics for Automotive Applications
This paper describes the development of a plasma process to produce a durable water repellent
and anti-stain thin film on synthetic textile, utilized for the upholstery in the automotive field. The
coatings were deposited in non equilibrium low pressure plasmas fed with 1H, 1H, 2H-perfluo-ro-
1-decene employing, as substrates, polyethylene terephthalate and polyethylene terephthalate
thermo-coupled to polyurethane foam. It was found that the XPS F/C ratio of the deposit was
higher than 1.4 and that the treated textile was always very hydrophobic (WCA > 140Ë) and oil resistant
(motor oil CA > 110Ë), even after wear
Plasma Enhanced-Chemical Vapour Deposition of Scuff-Resistant Hydrogenated Amorphous Carbon Coatings on C100 Steel
Hydrogenated amorphous carbon coatings, deposited by low pressure plasma to minimize the wear of C100 steel components, were optimized and characterized. In order to ensure good adhesion of the films to the steel surface, a thin Ti interlayer was deposited, by magnetron sputtering,
before the plasma deposition. The chemical characterization of the deposits was performed by means of RAMAN, XPS, RBS and ERDA analysis, while nanoindentation, nanoscratch and nanowear tests allowed to estimating the tribomechanical properties of the deposits, with the aim of evaluating their scuff-resistance. It was found that the optimized plasma deposited hydrogenated amorphous carbon coatings were well adherent to C100 steel and increased more than 70% its surface hardness