1,721,097 research outputs found
Antarctic aerosol: direct gravimetric measurement of the mass; soluble/insoluble fractionation of trace heavy metals; characterization by single particle aerosol mass spectrometry.
No full textGlobal Warming: Influence of Raising Temperature on Fatty Acid Composition of Muscle of Antarctic Teleost Trematomus Bernacchii, Analysed by Gas-Chromatography Mass-Spectrometry
No full textRecent sudden decrease of lead in Adriatic coastal seawater during the years 2000-2004 in parallel with the phasing out of leaded gasoline in Italy
No full textIn parallel with the process of lead removal from gasoline in Italy, a research programme was undertaken to study the lead content of Adriatic coastal seawater. In the period 2000–2004 seawater was collected systematically at three sites along the coast line close to the city of Ancona: (i) the mouth of the River Esino, (ii) an area close to the Api refinery and (iii) Portonovo beach, a less impacted zone located along the coast of Mt. Conero. All samples were analyzed by Square-Wave Anodic-Stripping Voltammetry (SWASV). The results show that dissolved Pb content in coastal seawater diminished from an overall median value of 0.25 nmol/L in 2000–2001 to 0.12 nmol/L in 2003–2004, with a decrease of about 50% (statistically significant at 95% significance level). This decrease has been correlated to the concurrent decrease of lead consumption in gasoline in Italy which led to a reduction of ~65% Pb emissions into the atmosphere in the same period (r=0.8791, p<0.05)
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
Determination of Proline in honey: comparison between official methods and optimization of the analytical methodology.
No full textPolveri sottili: descrizione e metodi analitici avanzati. Riconoscimento e ripartizione delle fonti mediante spettrometria di massa di singole particelle.
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Anodic stripping voltammetric determination of Cd in the liver of the Antarctic teleost Trematomus bernacchii for studies on metal bioaccumulation.
No full textRecent temporal variations of trace metal contents in wine.
No full textXXIV Congresso Nazionale della Società Chimica Italiana Lecc
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