Wednesday 4 December 2013

Day 1 on Beamline B22 Sample prep nightmares

Another 5.15 am start to get to Diamond for 10 am. This time I'm here for 5 days to try and do some infrared mapping to locate amorphous calcium carbonate in the granules. Liane and Steffi arrived on Monday and have been working to optimise the system for the calcite and also their snow algae. We've hit a few problems. There are problems with the samples we cryomicrotomed last time we were here. The samples are stored at - 80 C but when they are transferred to the sample holders for the beamline water in the atmosphere sticks to the samples and freezes producing ice crystals. This makes the samples no good for analysis.

Plan B was to use the samples I prepared in York and Liane prepared in Leeds - these are simply balls of calcite embedded in araldite. We tried microtoming these and the samples just crumbled. It looks like the balls are too fragile to slice into 10 micron thicknesses.

Plan C is to have a final go with basic granules and the cryomicrotome tomorrow but the feeling is that it's a long shot. Plan D is to simply crush the granules and look for amorphous calcium carbonate in the powder - we'll try that tomorrow or possibly Friday depending on how things go tomorrow.

For our next beamtime in February we'll prepare some "classic" thin sections which should definitely work.

Steffi (left) and Liane (right) setting up a sample map.


In the meantime we are running some of Steffi and Liane's snow algae samples that have simply been smeared onto slides.

Liane is now off to bed (11 pm). Steffi and I will stay up until 2 am to put on another sample then we'll reconvene at 9 am tomorrow.

Oh the joys of beamtime

2 comments:

  1. Sounds like i am a sissy going to bed at 11 - but you forgot to say that i blooming had to get up at 3 to change the map
    How convenient ....

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    1. Fair enough - I hold up my hands. Liane has done more of the 3 am slots than me this visit.

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