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The development of a unique analytical method for the determination of five classes of persistent organic pollutants (POPs) in atmospheric gas and the particle phase through gas chromatography coupled to high-resolution mass spectrometry is presented. Every step of the pre-analytical and analytical optimization process is described. Great effort was put into simplifying the traditional techniques, with reference to EPA and literature methods. Automated instruments were used for sample extraction and cleanup in order to enhance repeatability and reduce contamination risks. Unlike most common approaches, no separation of the analytes was performed before the GC analysis in order to avoid sample fractionation and to save time and materials. This allowed low instrumental and method detection limits (pg to sub-pg) to be achieved. Accuracy and precision were tested by fortifying the matrix and analysing standard reference materials (NIST SRM 1649b Urban Dust and 2585 Organic Contaminants in House Dust). The method was applied to five samples from Terra Nova Bay, Antarctica. Concentrations of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), polybrominated diphenyl ethers (PBDEs) and polycyclic aromatic hydrocarbons (PAHs) are presented. Lighter compounds dominate the distribution and are mainly present in the gaseous phase. The observed pattern may be attributable to long-range transport. Results are in general agreement with literature data, where available.

Deforestation associated with the initial settlement of New Zealand is a dramatic example of how humans can alter landscapes through fire. However, evidence linking early human presence and land-cover change is inferential in most continental sites. We employed a multi-proxy approach to reconstruct anthropogenic land use in New Zealand’s South Island over the last millennium using fecal and plant sterols as indicators of human activity and monosaccharide anhydrides, polycyclic aromatic hydrocarbons, charcoal and pollen as tracers of fire and vegetation change in lake-sediment cores. Our data provide a direct record of local human presence in Lake Kirkpatrick and Lake Diamond watersheds at the time of deforestation and a new and stronger case of human agency linked with forest clearance. The first detection of human presence matches charcoal and biomarker evidence for initial burning at c. AD 1350. Sterols decreased shortly after to values suggesting the sporadic presence of people and then rose to unprecedented levels after the European settlement. Our results confirm that initial human arrival in New Zealand was associated with brief and intense burning activities. Testing our approach in a context of well-established fire history provides a new tool for understanding cause-effect relationships in more complex continental reconstructions.

Despite geographical isolation and almost complete absence of human settlements, Antarctica is affected by Persistent Organic Pollutants (POPs): the traces of these impacts are recorded in the snow. Although POPs were detected in Antarctica decades ago, there are still large knowledge gaps and a comprehensive understanding of their fundamental patterns is lacking. In this study, polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs, including the non-Aroclor PCB-11), polybrominated diphenyl ethers (PBDEs) and polycyclic aromatic hydrocarbons (PAHs) were measured in surface snow samples from five selected locations of Northern Victoria Land. To our knowledge this is the first study providing ground-based measurements of PCDD/Fs, PCB-11 and PBDEs in Antarctic surface snows, including the plateau. Long-range atmospheric transport (LRAT) followed by regional redistribution were hypothesized as governing sources of POPs to the Antarctic Plateau, but also local pollution from human activities was found. Sub-pg L− 1 levels of PCDD/Fs were detected in the coastal samples, while PCBs (ΣPCBs 110-580 pg L− 1) generally showed a decrease with respect to the past decades. Similar concentrations of PBDEs (ΣBDEs 130–340 pg L− 1) were found, mainly attributable to the congeners BDE-47 and BDE-99. PAHs (ΣPAHs 0.65–140 ng L− 1) were the most abundant compounds in all sites with an unexpected high value near a refueling point. Possible source areas of contamination were investigated by means of the HYSPLIT model

Organic molecular markers determined in a sediment core (V95-1A-1P) from Lake Victoria (East Africa) were used to reconstruct the history of human\ud impact and regional fire activity during the Early Iron Age (~2400 to ~1100 yr BP). Fire history was reconstructed using levoglucosan and polycyclic\ud aromatic hydrocarbons (PAHs) as markers for biomass burning that demonstrate two distinct fire periods peaking at 1450–1700 and 1850–2050 cal. yr\ud BP. A partial correlation between levoglucosan and PAHs is interpreted as different transport behaviors and burn temperatures affecting the proxies. A\ud fecal sterol index (CoP-Index) indicates the presence of humans near the lakeshore, where the CoP-Index lags a few centuries behind the fire peaks. The\ud CoP-Index peaks between 1850 and1950 cal. yr BP and between 1400 and 1500 cal. yr BP. Retene, a PAH that indicates softwood combustion, differs\ud from other PAHs and levoglucosan by abruptly increasing at ~1650 cal. yr BP and remaining high until 1200 cal. yr BP. This increase may potentially signal\ud human activity in that the development of metallurgy and/or ceramic production requires highly efficient fuels. However, this increase in retene occurs\ud at the same time as severe drought events centered at ~1500 and ~2000 yr BP where the droughts and associated woodland to grassland transition may\ud have resulted in more intense fires. The grassland expansion could have created favorable conditions for human activities and triggered settlement growth\ud that in turn may have created a positive feedback for further landscape opening

In order to determine sterols and stanols in freshwater sediments to reconstruct the past presence of humans and pastoral animals, we developed an analytical method based on pressurised liquid extraction (PLE), clean-up performed using solid phase extraction (SPE) and sterol determination using gas chromatography-mass spectrometry (GC-MS) analysis. PLE extraction conditions were optimised using dichloromethane (DCM) and DCM/methanol mixtures. Clean-up was performed with 2 g silica SPE cartridges, and the concentrated extracts were eluted with 70 mL DCM. Extraction yield was evaluated using an in-house reference material spiked with (13)C-labelled cholesterol and aged for 10 days. In comparison with pre-extraction, where the sediment is extracted and then spiked with a known analyte concentration, this approach preserves the original composition of the sediment. DCM and DCM/methanol mixtures resulted in high extraction yields ranging from 86 to 92 % with good reproducibility (relative standard deviation (RSD) 5-8 %). PLE extraction yields obtained with DCM as the extracting solvent were about 1.5 times higher than extractions using an ultrasonic bath. The solvent extraction mixture and matrix composition strongly affected the solvent extraction composition where higher overall recoveries (70-80 %) for each compound were obtained with DCM. The extraction mixture and matrix composition also affected the analyte concentrations, resulting in a method precision ranging from 1 to 18 %. Diatomaceous earth spiked with 10 to 100 ng of sterols, and environmental samples fortified with suitable amounts of sterols provided apparent recovery values ranging from 90 to 110 %. We applied the method to environmental samples both close to and upstream from sewage discharge zones, resulting in substantially higher faecal sterol (FeSt) concentrations near the sewage. In addition, we also applied the method to a 37-cm freshwater sediment core in order to evaluate its applicability for obtaining vertical sterol profiles.

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A multiphase (MP) system composed of two immiscible liquids, water and isooctane, and commercial 5% Ru/C as a catalyst, both with and without an additional organic liquid (OL: tetrahydrofuran (THF), 2-methyl-THF, methyl isobutyl carbinol, and cyclopentyl methyl ether) was designed and investigated for the chemoselective catalytic hydrogenation of four model examples of biobased sugars and amino/amido-sugars. At 110 °C and 40 bar of H2, d-glucosamine hydrochloride and N-acetyl-d-glucosamine were converted selectively into their corresponding hydrogenated derivatives, 2-amino-d-sorbitol and 2-acetamide-d-sorbitol, respectively, isolated in >99% yields. Both the reagents and the products were converted and formed in the aqueous phase, respectively, while, by tuning the relative proportions of water, isooctane, and the third added liquid (particularly THF), the catalyst (Ru/C) was perfectly segregated in the organic layer, where it could be recycled and reused up to nine times without any loss of activity and selectivity, in a semicontinuous mode. Under such conditions, the reaction was implemented on a gram scale with a productivity up to 0.89 mmol 2-amino-d-sorbitol/(gcat h). The same hydrogenation efficiency and reagent/product/catalyst separation were achieved during the MP reactions of d-glucose and d-maltose. In this case, however, results were independent of the MP composition: at 120 °C and 20–40 bar of H2, using either H2O/isooctane or H2O/isooctane/OL systems, a quantitative conversion of d-glucose and d-maltose was reached with a selectivity up to 78 and >99% toward sorbitol and maltitol, respectively. Ru/C was perfectly separated out of the aqueous phase in both MP mixtures, with a negligible metal leaching, below 0.01 wt %. The multiphase approach for all the tested substrates proved not only to be an original and robust protocol to improve the product isolation and catalyst recycling, but also effective in preventing metal contamination in the synthesis of final derivatives.