MEarthSci Part 4: Lab Work Complete

Last time I left off in the saga of my master's research I was mid way through term and has just run my first set of XRD. Spoiler alert, the XRD (even though I did run it another time) ended up not being very useful for my research so was more of a fun learning experience than anything that will go towards my thesis. But that's the point right? Any exposure to new methods and techniques is a good chance to learn. Since then I've done a lot more lab work, including the long (well at least felt long to me) process of decarbonating my samples and then running those samples through the XRD and the mercury analyser again. I pleasantly surprised myself and managed to get my lab work complete by the end of term (got my last few hours in on the last day of term) which was something I had been stressy about to my supervisors in the last few weeks (sorry!). I also fit in a meeting with my supervisors to discuss my results and get my thoughts in place before going home for a week to see my mum. And now it's time to begin writing up my thesis!

Various lab photos form the last 4 weeks (from left to right): Crushing up my samples post decarbonation to run them through the XRD and mercury analyser again; my samples that have just been weighed out and dried in the oven overnight ready in their test tubes for decarbonation; the screen showing my second round of XRD analysis.

So the process of decarbonation is one worth talking about as it was a new style of lab work for me. This took place in the wet chemistry lab (which required a good 5 hours of online safety training and then an in person safety quiz in the lab in front of multiple PhD students which I'm sure you can imagine was great fun) but was very cool once I was allowed in. Decarbonating the rocks was basically to get rid of all the calcium carbonate in the samples. The thinking behind this was that we could re-run the samples in the XRD to see if the calcium carbonate had been essentially hiding/obscuring any signals. We also wanted to run he decarbonated samples in the mercury analyser again as well to see if anything had changed (in theory there should not have been any mercury hosted by the CaCO3 so no change but as we went on to discover this was not the case). Anyway, to do this I had to dissolve the samples in concentrated HCl. Sounds easy in principle but it ended up involving multiple hours of shaking test tubes, so much so that I had to tape up my wrists for my cheer practice that evening because they were so sore. I did find the process interesting even if a bit laborious and have attached some fun lab photos below.

Lab photos from decarbonation (from left to right): Test tubes of samples awaiting acid addition; samples post acid addition left on this shaking platform overnight to ensure thorough reaction; the fume hood set up where I was adding HCl to my samples.

Once decarbonation was done and the final XRD and mercury analysis was complete (a very stressful last week of term indeed) it became time to get my plots in order so I could bring them to show my supervisors. Unsure if I mentioned this before or not but I've been making my plots using R and actually find the process very satisfying. If I'm being honest, I have spent a lot of this process not really knowing what is going on. I can make the graphs and tell you what they are saying but the being able to suggest why this is happening or what my data actually means that didn't come quite as naturally for me. I think its because sedimentary mercury was not a topic I had done much reading about before so although I had basic knowledge from my degree and pre reading for my project I didn't know enough to really bring ideas to the table. Lucky for me my supervisors have been very patient and willing to walk me through things so I've started to get more of an idea as the project has gone on. As I've been making figures for my thesis this week I have started to become way more clear on what direction my thesis is going in and what the key research points are I'm trying to get across. Its been a whole process trying to figure out how to organise the many graphs and separate bits of data I ave into a coherent bit of writing but I was advised to make the figures first and then I know what the key bits to talk about are and this has really worked.

Now I'm at the point of only having one figure left to make and then it's write up time. It feels like I literally only just started this project and there is so much more to explore but just not enough time in only a one year masters. But that's where I am for now - spending my holidays writing up everything to hand the thesis in on the first week of term after the easter vac. then it'll be time to turn my mind to 6 weeks of hard core revision for the seminar courses I have been neglecting to get my lab work done before our final set of exams. I'll keep you updated...