Pure foraminifera as microanalytical reference material - NFHS-2-Nano-PelletTuesday, May 3, 2022
Foraminifera and their relevance in climate research
Before we get ahead of ourselves, what are foraminifera and why do they matter? Foraminifera (or short: forams) are single-celled organisms which can be found in salt and fresh water and even, rarely, in soil. Primarily however, they are marine and live planktonically throughout the water column in the ocean and benthically in the ocean floor. They produce a calcareous shell made from calcium carbonate (CaCO3) which they gradually expand with further growth-chambers. Apart from Calcium (Ca), Magnesium (Mg) is also incorporated. Depending on the ambient temperature during growth the ratio of Mg/Ca changes, this is the so-called Mg/Ca temperature proxy.
Further, paleoceanographers have figured out which species live where, meaning water temperatures from the sea surface to the seafloor can be reconstructed depending on which species of foram is being investigated. This, among other features, make forams an ideal tool for climate research and climate reconstruction of our planet’s oceans.
Microanalytical tools, such as laser ablation inductively coupled mass spectrometry (LA-ICP-MS) allow the analysis of single forams and even their individual growth-chambers enabling the reconstruction of water temperatures during its life cycle. This is a great advantage over classical wet chemical analysis where whole foraminifera are dissolved in acid. This means that only the entire foraminifera or even several foraminifera can be analysed on average and not individual areas. In addition, foraminifera are of course destroyed during dissolution in acid. The reconstructions of water temperatures are part of the basis of climate models, which in recent times have become and most likely will remain vital for understanding climate change.
Collaborating with NIOZ: NFSH-2-NP combines the best
The raw material for NFHS-2-NP was found at nearly 3 km depth (2878 m, to be accurate) off Namibia’s west coast at the Walvis Ridge. There, a core was taken out of the ocean floor by NIOZ researchers. When the core was examined, it turned out that one section (between the red markers) consisted almost entirely of foraminifera. Some coccolithophores were also present, but these could be sieved out. Subsequently, the material was processed into the reference material powder NFHS-1. However, this powder was too inhomogeneous and therefore not suitable for chemical microanalysis. Since NIOZ knew that we process such powders into ultra-homogeneous binder-free Nano-Pellets, they contacted us. We used our innovative processing method to produce ultra-homogeneous, binder-free nano-pellets (NFHS-2-NP).
The very successful collaboration has not only resulted in a unique reference material but also in a publication. A detailed description of what happened and who else was part of the cooperation can be found in the publication "A New Calcium Carbonate Nano-Particulate Pressed Powder Pellet (NFHS-2-NP) for LA-ICP-OES, LA-(MC)-ICP-MS and µXRF (Accepted proof)":
NFHS-2-NP Publication - Accepted Proofhttps://onlinelibrary.wiley.com/doi/10.1111/ggr.12425
We are proud to have been part of this journey and humbled by the trust given to us in processing this material. NFHS-2-NP is an example of what can be achieved when a community works together. In case this kind of project interests you for a similar or even a completely different material feel free to reach out, we are always happy to expand our horizons and collaborate with you.
Matching accessories and an outlook on microanalytical reference material sets
The NFHS-2 Nano-Pellets will be available in 10 mm diameter for LA-ICP-MS and in 13 mm diameter for µXRF. For the 10 mm Nano-Pellets we have developed two different mounts. A thin section-sized mount that holds up to 6, and an 1-inch round that holds up to 3 10 mm Nano-Pellets. These are available as polymer mounts, manufactured using the 3D printing process, or aluminium mounts CNC-milled from aircraft-grade aluminium and coated with Diamond Like Carbon (DLC).
Of course, not all places must be filled with NFHS-2-NP. Empty spaces can be filled up using other materials from our portfolio, or even just a dummy pellet so the hole does not disturb the gas flow in the ablation cell. NFHS-2-NP is a microanalytical recharacterized material (RCM). Further certified carbonates and iron ores will follow, as well as sets we have put together. These sets will be offered in a custom made and practical case. Stay tuned!
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