After my recent post on our application chemists developing a single extraction method for PAHs and PCBs from mussel tissue and soil using our Accelerated Solvent Extraction (ASE) technique, I received a really interesting biogeochemistryresearch study on using the same ASE technique from my HighWire subscription and thought our blog readers would be interested in reading about this fascinating study.
The study, titled, Climate impacts on human settlement and agricultural activities in northern Norway revealed through sediment biogeochemistry, (link to article, only the abstract is free) was conducted by researchers from the Climate System Research Center, Department of Geosciences, University of Massachusetts.
In the study, the researchers analyzed the presence of coprostanol (a fecal sterol) which is formed in the gut of most higher animals and birds and is frequently been used as a biomarker for the presence of human fecal matter in the environment (link to Wikipedia page) in a northern Norway lake. (By the way, the image is of a beautiful lake in Norway, just not the lake where they did the data collection.)
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From the abstract, “The arrival of humans is indicated by an abrupt increase in coprostanol (and its epimer epicoprostanol) in the sediments and an associated increase in 5β-stigmastanol (and 5β-epistigmastanol), which resulted from human and animal feces washing into the lake. Human settlement was accompanied by an abrupt increase in landscape fires (indicated by the rise in pyrolytic polycyclic aromatic hydrocarbons) and a decline in woodland (registered by a change in n-alkane chain lengths from leaf waxes), accelerating a process that began earlier in the Holocene. Human activity and associated landscape changes in the region over the last two millennia were mainly driven by summer temperatures, as indicated by independent tree-ring reconstructions, although there were periods when socioeconomic factors played an equally important role.”
In case you are new to the ASE technique, this technique is very suitable for the very fast extraction of solid and semisolid sample matrices using significantly reduced quantities (up to 90%) of common solvents at elevated temperatures and pressures. Results can be generated in a fraction of the time as compared to techniques such as Soxhlet and sonication. (Both links go to Wikipedia pages.) The other advantages include automating sample preparation and achieving filtration and clean-up of solid samples as part of the solvent extraction process in a single step.