Saturday, 7 December 2013

Day 4 of IR beamtime - more sample analysis action

So now we have some data. After 5 hours of analysis this is what you tend to end up with.

A screen shot from the FTIR software showing a series of point analysis.
During our sample preparation we were hoping to get nice round slices cut through granules. As mentioned previously what happened was that the granules crumbled as they cut and we just got material stuck around the edge. We've told the machine to do point analyses around the edge and in the middle screen in the image above you can see the points we analysed. Along the bottom you can just about see some typical spectra from those points. The really sharp eyed will notice the calcite peaks towards the right hand edge. What we need to do now (this will take some time) is process the data to see whether we get any variation in the ratio of amorphous calcium carbonate to crystalline material.

In order to maximise our time, Liane had brought her portable FTIR machine along as well.

Liane's portable FTIR machine in action
In many ways this works in the same way as the Synchrotron FTIR that we're using (it's all FTIR!). We used it to analyse a few samples from Emma Versteegh's project on the isotopic composition of granules. Emma's results suggest some sort of isotope fractionation from the initial secretion of the milky fluid in the calciferous glands to the secretion of the granules into the soil. This is most likely related to crystalisation of the amorphous calcium carbonate and we just needed to confirm that our samples start off amorphous and then crystalise - we have done, job done.

So all told, not a bad session - there is data to analyse that approximates to what we were after in the first place, we have done a few samples for another (related) project in our spare time and we have a good plan for what to do on the next visit in February.

Many thanks to Mark Frogley and Katia Webhe for their help and to Steffi Lutz and Liane Benning for putting up with me.

And the food wasn't as bad as last time either.....

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