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Determination of water soluble and insoluble (dilute-HCl-extractable) fractions of Cd, Pb and Cu in Antarctic aerosol by square wave anodic stripping voltammetry: distribution and summer seasonal evolution at Terra Nova Bay (Victoria Land).
No full textEight PM10 aerosol samples were collected in the vicinity of the “Mario Zucchelli” Italian Antarctic Station (formerly Terra Nova Bay Station) during the 2000–2001 austral summer using a high-volume sampler and precleaned cellulose filters. The aerosol mass was determined by differential weighing of filters carried out in a clean chemistry laboratory under controlled temperature and humidity. A two-step sequential extraction procedure was used to separate the water-soluble and the insoluble (dilute-HCl-extractable) fractions. Cd, Pb and Cu were determined in the two fractions using an ultrasensitive square wave anodic stripping voltammetric (SWASV) procedure set up for and applied to aerosol samples for the first time. Total extractable metals showed maxima at midsummer for Cd and Pb and a less clear trend for Cu. In particular, particulate metal concentrations ranged as follows: Cd 0.84–9.2 μg g−1 (average 4.7 μg g−1), Pb 13.2–81 μg g−1 (average 33 μg g−1), Cu 126–628 μg g−1 (average 378 μg g−1). In terms of atmospheric concentration, the values were: Cd 0.55–6.3 pg m−3 (average 3.4 pg m−3), Pb 8.7–48 pg m−3 (average 24 pg m−3), Cu 75–365 pg m−3 (average 266 pg m−3). At the beginning of the season the three metals appear widely distributed in the insoluble (HCl-extractable) fraction (higher proportions for Cd and Pb, 90–100%, and lower for Cu, 70–90%) with maxima in the second half of December. The soluble fraction then increases, and at the end of the season Cd and Pb are approximately equidistributed between the two fractions, while for Cu the soluble fraction reaches its maximum level of 36%. Practically negligible contributions are estimated for crustal and sea-spray sources. Low but significant volcanic contributions are estimated for Cd and Pb (∼10% and ∼5%, respectively), while there is an evident although not quantified marine biogenic source, at least for Cd. The estimated natural contributions (possibly including the marine biogenic source) cannot account for the high fractions of the metal contents, particularly for Pb and Cu, and this suggests that pollution from long-range transport is the dominant source
Studio del bioaccumulo di Cd nel fegato del teleosteo antartico Trematomus bernacchii mediante voltammetria di ridissoluzione anodica.
No full textDistribuzione di metalli pesanti in ambiente estuarino: frazionamento disciolto/particellato e determinazione mediante SWASV.
No full textAtti p. 241 (poster n. 30)
Bioaccumulo di cadmio nel pesce antartico Trematomus bernacchii rilevato mediante voltammetria (DPASV) durante esperimento in acquario.
No full textStudies on Cd bioaccumulation in the liver of the Antarctic teleost Trematomus bernacchii.
No full textMisure di Cd, Pb e Cu effettuate per la prima volta nelle spicole di spugne marine antartiche (mare di Ross)
No full textAnodic stripping voltammetric determination of Cd in the liver of the Antarctic teleost Trematomus bernacchii for studies on metal bioaccumulation.
No full textAerosol concentration in Central Antarctica: first PM10 measurements at Concordia Station (Dome C).
No full textRiassunti Estes
Square-wave anodic-stripping voltammetric determination of Cd, Pb and Cu in a hydrofluoric acid solution of siliceous spicules of marine sponges (from the Ligurian Sea, Italy, and the Ross Sea, Antarctica).
No full textSquare-wave anodic-stripping voltammetry (SWASV) was set up and optimized for simultaneous determination of cadmium, lead, and copper in siliceous spicules of marine sponges, directly in the hydrofluoric acid solution (~0.55 mol L−1 HF, pH ~1.9). A thin mercury-film electrode (TMFE) plated on to an HF-resistant epoxy-impregnated graphite rotating-disc support was used. The optimum experimental conditions, evaluated also in terms of the signal-to-noise ratio, were as follows: deposition potential −1100 mV vs. Ag/AgCl, KCl 3 mol L−1, deposition time 3–10 min, electrode rotation 3000 rpm, SW scan from −1100 mV to +100 mV, SW pulse amplitude 25 mV, frequency 100 Hz, ΔEstep 8 mV, tstep 100 ms, twait 60 ms, tdelay 2 ms, tmeas 3 ms. Under these conditions the metal peak potentials were Cd −654±1 mV, Pb −458±1 mV, Cu −198±1 mV. The electrochemical behaviour was reversible for Pb, quasi-reversible for Cd, and kinetically controlled (possibly following chemical reaction) for Cu. The linearity of the response with concentration was verified up to ~4 μg L−1 for Cd and Pb and ~20 μg L−1 for Cu. The detection limits were 5.8 ng L−1, 3.6 ng L−1, and 4.3 ng L−1 for Cd, Pb, and Cu, respectively, with td=5 min. The method was applied for determination of the metals in spicules of two specimens of marine sponges (Demosponges) from the Portofino natural reserve (Ligurian Sea, Italy, Petrosia ficiformis) and Terra Nova Bay (Ross Sea, Antarctica, Sphaerotylus antarcticus). The metal contents varied from tens of ng g−1 to ~1 μg g−1, depending on the metal considered and with significant differences between the two sponge species
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