Utrecht University’s researchers rely on microwave-assisted extraction for climate change studies
Marine Palynology and Palaeoceanography research group uses the newest microwave extraction system to study primeval seabed sediment.
The project is exploring the influence of ocean conditions on the melting process of Antarctica’s ice cap during climatically warm periods in the geological past, when carbon dioxide conditions were similar to today’s.
The findings could help predict how, and how quickly, climate change can melt the ice caps.
What can past ocean
conditions around the Antarctic ice cap tell us about today and tomorrow?
The Southern Ocean is getting warmer, and therefore quickly melting the Antarctic ice cap. It’s unclear whether this process is reversible, and if not, how long it will take for it to melt entirely.
Lab research on some of the oldest known seabed sediment may in the next few decades shed light on these ice and ocean dynamics. At Utrecht University, the research is being done by OceaNice, a project that got underway in February 2019 and is led by Peter Bijl, who holds a PhD in the environmental and climatological evolution of the early Paleogene Southern Ocean. The reconstructions show how greenhouse effects
and the changing ocean circulation over the past 80 million years have affected the global climate and sea levels.
(MAE) to analyze bores
Bijl’s team uses Microwave-Assisted Extraction (MAE), based on US EPA method 3546. This is a procedure for extracting water-insoluble or slightly water-soluble organic compounds from soils, clays, sediments, sludges, and solid
wastes. The solvability of the analytes increases sharply when the temperature of the solvent increases. The solvent, contained
in closed vessels, is heated by microwave to temperatures exceeding atmospheric boiling point. The pressure in the closed system rises, causing the solvents to remain liquid even above
their boiling point. The use of glass tubes prevents cross-contamination, which is crucial considering the tiny amounts of organic material in the samples.
MAE is faster and produces more accurate and reproducible results than other methods. It is relatively inexpensive, too, because only small amounts of solvents and energy are needed and little cleaning and waste removal is required. That was more than enough reason for OceaNice to invest in an ETHOS X microwave extraction system
with a Milestone fastEX-24 rotor.
Procedure si easily explained:
“Sample preparation consists of grinding the sample into a fine powder with an old-fashioned pestle and mortar. Next, the
powder is put in a glass tube and we add the solvent, a mixture of dichloromethane and methanol. The tube is then sealed in a
Teflon-coated vessel. The extraction container is heated for 10 to 20 minutes, until it reaches extraction temperature."