Cellulose extraction – first trials

[caption id=”” align=”alignright” width=”320”] NaOH treatment of wood samples[/caption]

This week I started with a first -trial- cellulose extraction for my wood core stable isotope experiment. I have one plate to test the routine and look for possible flaws in the setup before ordering the final batch - money permitting. The setup has been running for a two days now. The picture in this posts shows the small wood samples submerged in NaOH to remove all resins, tannins etc. In a next step you add a strong acid to eat away the lignin and leave the cellulose behind.

The procedure is done in a hot water bath (60°C). I noticed that a lot of water evaporated, or more than I was used too when learning the procedure at GFZ Potsdam last October. Even with a small lid on it the water level decreased at a significant rate, with the possibility of not heating the reagents at the end of a treatment. After some thinking I found to culprit to be the laminary flow system on overdrive. Evaporation depends on the temperature of the water and the air, the evaporative surface area but also the velocity of the air mass above the surface. Given that all other parameters did not deviate significantly from the setup in Potsdam the more draughty laminary flow system in Ghent was an easy find. Opening the hood a bit more so the velocity of the air moving over the heated setup was less reduced the evaporation to within workable values. Covering the tray with a lid would reduce evaporation even further. Covering the water surface itself as with swimming pools, limiting the surface area from which you could evaporate water, would allow me to limit the refills after treatments even further. More on this later…

 

 

New paper in Nature Communications

The Nature Communications paper that was recently accepted and on which I contributed can be downloaded from the Nature website! (http://www.nature.com/ncomms/2013/130805/ncomms3269/full/ncomms3269.html). Congrats to all co-authors on pushing this along.

Another paper with Simon Lewis as lead author was also recently published. They used some of the our data to quantify above ground biomass for 260 plots across tropical africa (http://rstb.royalsocietypublishing.org/content/368/1625/20120295.short).

A new DR Congo field campaign?

I recently started to plan a new field campaign in both Yangambi as well as Yoko. The aim is to collect more wood (core) samples for stable isotope analysis as well as some leaf samples for a diachronic analysis of leaf morphology.

However, talking to people at the Royal Museum for Central Africa I might reconsider and make due with my current samples. It seems that tensions have run high between ‘white’ people and the local population both in Kisangani and Yangambi due to a clash of cultures and expectations. Although I never felt threatened during the last field campaign it only shows how vulnerable interpersonal relations are in DR Congo and how the colonial past still plays a big role in day to day interactions. Although we make it clear that we, as scientists, are not there for diamonds, sometimes it is still perceived to be so.

So I’m still on the fence on this one… more later…

Migrating my google sites pages

I’m finally migrating my old google sites blog to a more pleasing wordpress layout. Most of the data (downloads) will be migrated to the new site, old post on my google sites blog will be partially copied to populate my otherwise rather empty (at first) new blog. Older posts will remain on the old blog. I plan to rewrite some of my short tutorials (bash / GRASS / R scripts) in pages on this blog or blogposts. As such I will not copy these either.

Elsevier Peer Review Challenge

It seems that my 10 minutes of brain storming is paying off. I was selected as runner up in the Elsevier Peer Review Challenge (http://www.elsevierblogs.com/yourpeerreviewfuture/), scoring me a nice Galaxy Tab 10.1. Not bad for a small effort.

Looking forward to receiving my new toy!

Pagination


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