1,721,015 research outputs found
Messa a punto e ottimizzazione di metodologie analitiche per la determinazione di microinquinanti organici in matrici ambientali mediante cromatografia liquida con rivelazione via spettrometria di massa (hplc-ms/ms)
No full textPoly- and Perfluorinated Alkyl Substances in the Atmospheric Aerosol From a Rural Area of the Italian PFAS Hotspot (Veneto Region)
No full textPoly- and Perfluoroalkyl substances (PFASs) comprise a large group of more than 8.000 synthetic organic surfactants, of which only a limited number is known and analyzed. They have a wide range of industrial and commercial applications and are commonly found in a broad variety of industrial and consumer goods.
The physico-chemical properties of PFASs are not yet known in detail and are widely debated. Nevertheless, they show a high water solubility, which makes water resources the principal medium for their environmental transport. From the toxicological perspective, their environmental persistence and bioaccumulative properties make the PFASs a threat for the ecosystems and human health.
In 2013, a widespread PFAS contamination of surface, ground, and drinking waters was discovered in the Veneto Region (North-Eastern Italy), mainly caused by the RiMAr-Miteni S.p.A. industrial wastewaters. Active since the mid-‘60s, this chemical factory contaminated one of the largest underground aquifers in Europe. The inhabitants of the provinces within the so-called “PFAS Red Zone” were exposed, unbeknownst to them, to a PFAS contamination through drinking water for a long time, which led to high concentrations of these chemicals in citizens’ serum.
Given the high resonance and impact of this environmental and health emergency, the PFAS levels in the Veneto Region are continuously monitored in inland freshwaters by the Veneto Regional Environmental Prevention and Protection Agency. Nevertheless, limited information is available in literature on PFAS levels in the atmospheric aerosol, a matrix still little investigated, even in this highly impacted area.
This work was conducted in order to overcome the lack of data relating to the occurrence of PFASs in the atmosphere of the Veneto Region.
Sampling was conducted in a rural area near the municipality of Roncade, in the Treviso province, using a using a low-volume aerosol sampler Skypost PM (TRC-Tecora S.r.l.), equipped with a sequential sampler that operates at a flow rate of 38.3 L min−1. 76 aerosol samples were collected between 02/07/2021 and 12/01/2022.
Analysis of a broad spectrum of PFASs (target compounds, their precursors and substitutes) was carried out by High Performance Liquid Chromatography coupled with tandem Mass Spectrometry (HPLC-MS/MS).
The compounds detected most frequently were the fluorotelomer 6:2 FTS and PFOS, while those with the highest concentration were 6:2 diPAP (802 ± 591 pg m−3), Me-FOSAA (15 ± 10 pg m−3 ), Et-FOSAA (9 ± 8 pg m−3), and the new generation compound GenX (13 ± 12 pg m−3).
It has been observed that the total monthly PFAS concentration in the particulate increases in the winter season, especially for the compounds that belong to the classes of Perfluorinated carboxylic acids (PFCAs) and Perfluorinated sulfonic acids (PFSAs). This evidence is related to the reduction of their volatility with the decrease in temperature. Furthermore, the total monthly PFAS concentration increases with increasing relative humidity during the sampling seasons.
Generally, the concentration levels detected in this study for PFOA and PFOS are comparable with those reported in literature
Fast and sensitive method for determination of domoic acid in mussel tissue
Full text linkDomoic acid (DA), a neurotoxic amino acid produced by diatoms, is the main cause of amnesic shellfish poisoning (ASP). In this work, we propose a very simple and fast analytical method to determine DA in mussel tissue. The method consists of two consecutive extractions and requires no purification steps, due to a reduction of the extraction of the interfering species and the application of very sensitive and selective HILIC-MS/MS method. The procedural method was validated through the estimation of trueness, extract yield, precision, detection, and quantification limits of analytical method. The sample preparation was also evaluated through qualitative and quantitative evaluations of the matrix effect. These evaluations were conducted both on the DA-free matrix spiked with known DA concentration and on the reference certified material (RCM). We developed a very selective LC-MS/MS method with a very low value of method detection limit (9 ng g-1) without cleanup steps
Studio della composizione chimica nelle diverse classi dimensionali dell’aerosol artico idrosolubile
Full text linkLo studio della composizione chimica dell’aerosol atmosferico idrosolubile è di fondamentale importanza ambientale dato che i composti idrosolubili possono influenzare l’igroscopicità delle particelle di aerosol e agire come nuclei di condensazione delle nubi.
In questo studio sono state analizzate le specie anioniche e cationiche, gli acidi carbossilici, i mono- e di-saccaridi, gli alcool-zuccheri ed anidro-zuccheri, i composti fenolici, gli L e D- amminoacidi (FAA e CAA) e i composti di foto-ossidazione dell’α-pinene (acido cis-pinonico ed acido pinico). Le analisi sono state effettuate su campioni di aerosol atmosferico raccolti da aprile a giugno 2015 a Ny Ålesund (78°55'07''N, 11°53'30''E; Isole Svalbard, Norvegia). L’aerosol è stato campionato con un impattore a cascata ad alto volume (TE-6070, PM10 high volume air sampler) che ha permesso di suddividere il particolato atmosferico in sei frazioni dimensionali: 10.0–7.2, 7.2–3.0, 3.0–1.5, 1.5–0.95, 0.95-0.49, <0.49 μm.
La quantificazione dei composti di foto-ossidazione dell’α-pinene, di zuccheri ed alcool- zuccheri, degli amminoacidi combinati e degli enantiomeri L e D in ambienti polari è scarsamente studiata e sono stati condotti solamente alcuni studi preliminari sull'andamento degli amminoacidi in ambienti artici e sull’andamento di zuccheri ed alcool-zuccheri in aree sub-artiche norvegesi e finlandesi. I traccianti da combustione da biomassa, in particolare l’anidro-zucchero levoglucosan e i composti fenolici, risultano invece già abbondantemente studiati in queste aree remote.
L’obiettivo è di valutare i processi di trasporto intercontinentali confrontando la composizione chimica dell’aerosol nelle diverse frazioni dimensionali. Lo studio di questi composti ha permesso inoltre di investigare i processi di formazione e di trasformazione dell’aerosol di origine biogenica e da combustioni da biomassa
Levoglucosan and phenols in Antarctic marine, coastal and plateau aerosols
Full text linkDue to its isolated location, Antarctica is a natural laboratory for studying atmospheric aerosols and pollution in remote areas. Here, we determined levoglucosan and phenolic compounds (PCs) at diverse Antarctic sites: on the plateau, a coastal station and during an oceanographic cruise. Levoglucosan and PCs reached the Antarctic plateau where they were observed in accumulation mode aerosols (with median levoglucosan concentrations of 6.4pgm-3 and 4.1pgm-3, and median PC concentrations of 15.0pgm-3 and 7.3pgm-3). Aged aerosols arrived at the coastal site through katabatic circulation with the majority of the levoglucosan mass distributed on larger particulates (24.8pgm-3), while PCs were present in fine particles (34.0pgm-3). The low levoglucosan/PC ratios in Antarctic aerosols suggest that biomass burning aerosols only had regional, rather than local, sources. General acid/aldehyde ratios were lower at the coastal site than on the plateau. Levoglucosan and PCs determined during the oceanographic cruise were 37.6pgm-3 and 58.5pgm-3 respectively. Unlike levoglucosan, which can only be produced by biomass burning, PCs have both biomass burning and other sources. Our comparisons of these two types of compounds across a range of Antarctic marine, coastal, and plateau sites demonstrate that local marine sources dominate Antarctic PC concentrations
Characterization of Soil Organic Matter along an elevation gradient at Stelvio Pass (Italian Alps)
Full text linkParticle size distribution of inorganic and organic ions in coastal and inland Antarctic aerosol
Full text linkThe concentration and particle-size distribution of ionic species in Antarctic aerosol samples were determined to investigate their potential sources, chemical evolution, and transport. We analyzed aerosol samples collected at two different Antarctic sites: a coastal site near Victoria Land close to the Italian Research Base “Mario Zucchelli”, and another site located on the Antarctic plateau, close to Italian-French Concordia Research Station. We investigated anionic compounds using ion-chromatography coupled to mass spectrometry, and cationic species through capillary ion chromatography with conductometry. Aerosol collected close to the coast was mainly characterized by sea salt species such as Na+, Mg2+, and SO42−. These species represented a percentage of 88% of the total sum of all detected ionic species in the aerosol samples from the coastal site. These species were mainly distributed in the coarse fraction, confirming the presence of primary aerosol near the ocean source. Aerosol collected over the Antarctic plateau was characterized by high acidity, with nss-SO42−, NO3−, and methanesulfonic acid as the most abundant species. These species were mainly distributed in the <0.49 μm fraction, and they had a behavior of a typical secondary aerosol, where several chemical and physical processes occurred
Characterization of the water soluble fraction in ultrafine, fine, and coarse atmospheric aerosol
No full textWater soluble organic carbon significantly contributes to aerosol's carbon mass and its chemical composition is poorly characterized due to the huge number of species. In this study, we determined 94 water-soluble compounds: inorganic ions (Cl−, Br−, I−, NO3−, SO42−,K+, Mg+, Na+, NH4+, Ca2+), organic acids (methanesulfonic acid and C2-C7 carboxylic acids), monosaccharides, alcohol-sugars, levoglucosan and its isomers, sucrose, phenolic compounds, free l- and d-amino acids and photo-oxidation products of α-pinene (cis-pinonic acid and pinic acid). The sampling was conducted using a micro-orifice uniform deposit impactor (MOUDI) at the urban area of Mestre-Venice from March to May 2016. The main aim of this work is to identify the source of each detected compound, evaluating its particle size distribution. Clear differences in size distributions were observed for each class of analyzed compounds.\ud
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The positive matrix factorization (PMF) model was used to identify six factors related to different sources: a) primary biogenic aerosol particles with particle size > 10 μm; b) secondary sulfate contribution; c) biomass burning; d) primary biogenic aerosol particles distributed between 10 and 1 μm; e) an aged sea salt input and f) SOA pinene. Each factor was also characterized by different composition in waters soluble compounds and different particles size distribution
The ubiquity of neonicotinoid contamination: Residues in seabirds with different trophic habits
No full textNeonicotinoids are one of the most diffusely used classes of pesticides whose level of danger toward non-target invertebrate and vertebrate species has raised increasing concern in the last decades. Among vertebrates, birds are particularly susceptible to unintentional neonicotinoid poisoning since they can be exposed through different pathways, including ingestion of dressed seeds, sucking of contaminated pollen, ingestion of sprayed insects, predation on contaminated aquatic and terrestrial preys. In the present study, we investigated the possible exposure of seabirds by measuring the residues of five neonicotinoids (acetamiprid, clothianidin, imidacloprid, thiacloprid and thiamethoxam) in samples of pooled feathers collected from fledglings of the strictly piscivorous Sandwich tern (Thalasseus sandvicensis) and the mixotrophic species Mediterranean gull (Ichthyaetus melanocephalus). At least one neonicotinoid was quantified in all the Mediterranean gull samples (n = 11) and 89% of the analysed Sandwich tern samples (n = 36). The active principles with the highest quantification rates were imidacloprid (100% in Mediterranean gulls and 58% in Sandwich terns) and clothianidin (100% in Mediterranean gulls and 61% in Sandwich terns), while thiacloprid was the less frequently detected pesticide (<20% of samples in both species). Mean concentrations ± standard error for imidacloprid, clothianidin and thiamethoxam were 8.8 ± 1.4, 4.5 ± 0.19 and 0.16 ± 0.02 ng g−1 for the Mediterranean gull, and 5.8 ± 0.55, 0.60 ± 0.08 and 0.36 ± 0.03 ng g−1for the Sandwich tern, respectively. Our data evidenced the exposure of seabirds to neonicotinoids and the further need to investigate the extent of neonicotinoid contamination in non-agricultural ecosystems
Water soluble compounds in size-segregated Arctic aerosol at Gruvebadet, Ny-Ålesund in 2013, 2014, 2015 and 2018-2019
No full textWater Soluble Organic Compounds (WSOCs) chemistry in the Arctic region occurs through several sources, depending on the considered compound. We examine here L- & D- Free and Combined amino acids, mono-saccharides, di-saccharides, anhydro-sugars, alcohol-sugars, organic acids and major cations and anions in 2013, 2014, 2015 and 2018 Arctic campaign at Gruvebadet Laboratory, close to Ny-Ålesund (Svalbard Island - 78°55′03″N, 11°53′39″E). A multi-stage Andersen impactor (TE-6000 series, Tisch Environmental Inc.) was used to collect aerosol samples on six pre-combusted (4 h at 400 °C in a muffle furnace) quartz fiber filters. The sampler accumulated particles with a cut-off diameters of 10.0 μm, 7.2 μm, 3.0 μm, 1.5 μm, and 0.95 μm on slotted filters and <0.49 μm on backup filter. The frequency of sampling varied from 1 to 10 days with a total air volume of about 1000 or 15000 m³ per sample
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