Daily PM10 aerosol samples were collected at the Gruvebadet observatory, Ny-Å lesund (Svalbard Islands), during the spring-summer 2014 Italian Arctic Campaign. A total of 136 samples were analysed for ion (inorganic anions and cations, selected organic anions) composition aiming to evaluate the seasonal pattern of sulfate, as a key component of the Arctic haze. Ionic balances indicated a strong sulfate seasonality with mean spring concentration about 1.5 times higher than that measured in summer. The spring and summer aerosol was almost neutral, indicating that ammonia was the major neutralizing agent for atmospheric acidic species. The linear regression between sulfate from potential acidic sources (non-sea salt sulfate and non-crustal sulfate) and ammonium indicated that the mean sulfate/ammonium ratio was intermediate between semi-(NH 4 HSO 4 ) and complete ((NH 4 ) 2 SO 4 ) neutralization. Using sea-salt sodium as sea-spray marker, non-sea-salt calcium as crustal marker and methanesulfonic acid as biogenic marker, a detailed source apportionment for sulfate was carried out. The anthropogenic input (calculated as the differences between total sulfate and the sum of sea-salt, crustal and biogenic contributes) was found to be the most relevant -016-0517-7 contribution to the sulfate budget in the Ny-Å lesund aerosol in summer and, especially, in spring. In this last season, crustal, sea-salt, biogenic and anthropogenic sources accounted for 3.3, 12.0, 11.5 and 74.8 %, respectively.

During the 2010-2011 austral summer, size-segregated aerosol samples were collected at a coastal Antarctic site (Terra Nova Bay, Victoria Land) and analysed for major and trace elements and lead isotopic composition, in order to provide a better understanding of the sources of metals and their transportation pathways towards Antarctica. Aerosol size fractionation was performed by a cascade impactor, able to collect aerosol particles of aerodynamic diameter 10-7.2, 7.2-3.0, 3.0-1.5, 1.5-0.95 and 0.95-0.49 mu m. It was found that Al, Co, Fe, Li, Mn, Rb, Y and V were mainly related to crustal inputs, whereas the marine contribution was significant for Li, Mg, Na and Rb. An additional anthropogenic source influencing the concentration of Cr, Cu, Mo and Pb was clearly demonstrated. The concentration of the elements associated to the crustal and marine inputs showed high values in the coarse mode (7.2-3.0 mu m), whereas the anthropogenic elements were also characterised by a high concentration in the finer (1.5-0.95 mu m) particles. The study of the temporal trends of the measured chemical markers along with the meteorological variables revealed that both the crustal and anthropogenic elements were related to the air masses carried by the katabatic wind from the inland, whereas the marine input appeared to be higher in January when the sea-ice extent was reduced. Finally, lead isotope ratios pointed out that the anthropogenic input was likely related to the polluted aerosols from South America and Australia, representing the predominant fraction (50-70%) of the lead measured in the samples

Environmental context. Antimony is an environmental contaminant of increasing concern, due to its growing industrial usage in flame retardants, lead alloys, glass, ceramics and plastics. Here we show, using X-ray absorption spectroscopy, that antimony may be trapped in wetland sediments by reduced sulfur. This finding has implications for the management and remediation of wetlands contaminated with antimony.Abstract. The biogeochemistry of antimony (Sb) in wetland sediments is poorly characterised, despite their importance as contaminant sinks. The organic-rich, reducing nature of wetland sediments may facilitate sequestration mechanisms that are not typically present in oxic soils, where the majority of research to date has taken place. Using X-ray absorption spectroscopy (XAS), we present evidence of antimony speciation being dominated by secondary antimony-sulfur phases in a wetland sediment. Our results demonstrate that, by incorporating a newly developed Sb III -organic sulfur reference standard, linear combination fitting analysis of antimony K-edge XAS spectra and robust statistical assessment of fit quality allows the reliable discrimination of Sb III coordination environments. We found that a contaminated wetland sediment in New South Wales, Australia, contained 57 % of the total antimony as Sb III -phases, with 44 % present as a highly-disordered antimony phase, likely consisting of Sb III complexed by organic sulfur (e.g. thiols) or an amorphous Sb III sulfide (e.g. SbS 3 ). The methodological approach outlined in this study and our identification of the importance of reduced sulfur in sequestering antimony has implications for future research in the area of antimony biogeochemistry, and for the management of both natural and artificial wetlands contaminated with antimony.

During the 2013 Arctic campaign, direct measurements and size-segregated samplings of atmospheric aerosol were carried out from March to September at the Gruvebadet observatory in Ny-Å lesund (78°56 0 N, 11°56 0 E; Svalbard Islands). Continuous size distribution measurements (104 size classes) were performed both in the nano-(TSI-SMPS system) and micro-metric (TSI-APS device) range with a resolution of 10 min. Aerosol sampling was carried out on daily basis (PM 10 fraction, 00:01-23:59 UTC) and with a 4-day resolution (four-stage cascade impactor). A back-trajectory analysis was performed for specific events to understand transport processes and possible source areas of aerosol reaching Ny-Å lesund. Aerosol samples were analyzed for ion composition (inorganic cations and anions, selected organic anions) by a threechromatograph system after extraction in ultra-sonic bath. Special attention was spent in identifying and interpreting the seasonal pattern of natural and anthropic chemical markers. Sea spray aerosol was evenly distributed along all the sampling period with maxima related to wind speed. Its size distribution peaks in 1.0-2.5 or 2.5-10 lm, depending on the transport conditions and distance from source areas. Anthropic sulfate dominates the spring aerosol load (Arctic Haze), both in acidic form (H 2 SO 4 ) and in partially or totally neutralized ammonium salts. Biogenic contributions, marked by methanesulfonic acid, are relatively relevant in late spring-early summer and are distributed in the finest aerosol fraction (\1.0 lm).

No abstract

Size-segregated (PM10) aerosol samples were collected at Ny-Ålesund (Svalbard Islands, Norwegian Arctic) from April to September 2012 and analysed for lead content and isotopic composition (207Pb/206Pb and 208Pb/206Pb), along with other chemical tracers, such as aluminium (crustal marker) and non-sea-salt sulphates (anthropogenic and marine biogenic marker). It was found that most of lead reaching Ny-Ålesund is anthropogenic, with a marked seasonality of both the concentration and isotopic signature. Particularly, average lead concentration in summer was significantly lower than in spring (p=0.003), whereas 208Pb/206Pb decreased from 2.107±0.002 to 2.090±0.005 (mean±95%-confidence level, p=6.0 10-6). A comparison of the measured isotopic ratios to literature data suggests that the atmospheric lead reaching the Arctic during spring can be mainly related to inputs from eastern Eurasia, whereas North America appeared to be the major source during the summer. Experimental results and sampling strategy also indicate that local inputs of crustal and anthropogenic lead play a minor role. The source-receptor relationship was confirmed by a back-trajectory cluster analysis of air-masses reaching the sampling sit

Reliable determination of Pb isotope ratios in Antarctic snow is challenging because of the low analyte concentration and the low volume of sample typically available. In this work, a combination of a total sample consumption introduction system (the torch-integrated sample introduction system, TISIS) with multi-collector ICP-mass spectrometry (MC-ICP-MS) was used for this purpose. With this instrumental setup, accurate and precise determination of Pb isotope ratios was possible at concentrations as low as 0.5 ng mL(-1), while using 0.2 mL of solution only (total amount of Pb: 100 pg). At 10 ng mL(-1), the repeatability for the Pb-207/Pb-206 ratio was 0.16 parts per thousand RSD. The concentration range was further extended downwards by using 100-fold analyte element preconcentration via freeze-drying of 20 g of snow. The Pb concentration in procedural blanks was 0.5 +/- 0.3 pg g(-1), enabling the determination of Pb isotope ratios in snow samples containing down to 5 pg g(-1) of Pb. After development and validation, the procedure was applied to snow samples collected at Dome C (East Antarctic Plateau) on a monthly basis during the 2006 and 2010 campaigns. The method developed was able to reveal a seasonal variation in the Pb isotope ratios occurring during 2006 and strong inter-annual variation between the two campaigns

Measurement of lead isotope ratios in environmental matrices using inductively coupled plasma-dynamic reaction cell-mass spectrometry at low sample consumption rates was investigated. Two micro-sample introduction systems were evaluated, namely the PFA micronebuliser associated with a low-volume spray chamber, working at 150 mL min?1 and the total-consumption sample introduction system TISIS, operating at 20 mL min?1. In both cases, the dynamic reaction cell pressurised with ammonia was applied to improve the precision by collisional damping. Under optimal operating conditions, 208Pb/207Pb and 206Pb/207Pb ratios were accurately determined with an internal precision of 0.12–0.13% and 0.17–0.18% (%RSD, n ¼ 10, c ¼ 10 mgL?1; t ¼ 10 s). The sample consumption for the assessed sample introduction systems was less than 1.5 mL and 200 mL, allowing the precise analysis of limited-size samples and pre- concentrates. The developed method was characterised in terms of the analytical working range, in-cell interference, and uncertainty estimation. The applicability of the analytical method was demonstrated by the analysis of the lichen reference material CRM 482, as well as those of several environmental samples collected from polar regions, including atmospheric particulate, snow, marine suspended particulate matter and sediment. In particular, by combining a simple pre-concentration procedure with the application of TISIS, it was possible to perform the lead isotope analysis of Antarctic snow samples at the pg g?1 concentration level