It’s #RealTimeChem week (@RealTimeChem on Twitter). To celebrate, I’m going to illustrate both some of the procedures we do in the laboratory and how #RealTimeChem works. I’ll also show how geochemistry, while somewhat different from ‘traditional’ chemistry (geochemists tend to have degrees in geology and not in chemistry, for example), it is still chemistry.
I’m a geochemist. More specifically, I’m a stable isotope geochemist. I’ve written a few blog posts on the geochemistry that I do and my own research. I won’t go too much into details, other than to say that, no, I don’t work with radioactive things like uranium or plutonium. Nothing radioactive. I just look at different stable (not radioactive) isotopes of things like carbon, nitrogen, and oxygen.
The materials I analyze are mostly ‘geological,’ meaning that I’m trying to analyzed carbon, nitrogen, and oxygen from rocks and minerals. This includes skeletal materials from fossils and modern animals, because bones and shells are actually made of minerals.
A certain amount of preparation has to take place before I can just analyze samples. I have to purify them, and then do something to get the elements of interest out and into the mass spectrometer.
What I’m going to talk about here is the step-by-step of a chemical pre-treatment of bioapatite, the mineral that makes up bones and teeth. We are interested in analyzing carbon and oxygen from bioapatites. We need to be sure that there are no other sources of carbon or oxygen on the samples (like dirt, hair, dust) that can affect our analysis.
I’m going to do this in the spirit #RealTimeChem week should work as well. #RealTimeChem is about tweeting your chemistry research in real time, as in what you are doing right at the moment. I pretreated some samples the other day and live-tweeted my progress. I’ve collected those tweets here.
Pretreating bioapatites for isotopic analysis. First, react powdered enamel with hydrogen peroxide. #RealTimeChem twitter.com/paleololigo/st…
— Penny Higgins (@paleololigo) April 18, 2013
//platform.twitter.com/widgets.jsThe hydrogen peroxide is for getting rid of organic material like hair or oils off my fingers.
Vortexing #RealTimeChem twitter.com/paleololigo/st… — Penny Higgins (@paleololigo) April 18, 2013
Let the samples react undersonication for 20 minutes. #realtimechem twitter.com/paleololigo/st… — Penny Higgins (@paleololigo) April 18, 2013
Samples in the centrifuge. Rinse, rinse, rinse. #realtimechem twitter.com/paleololigo/st… — Penny Higgins (@paleololigo) April 18, 2013
That tweet sounded a little like a song. I got some help coming up with a tune and a few lyrics:
Samples in the centrifuge, rinse, rinse, rinse! Out with impurities, spins, spins, spins! (to tune of “Up on the Rooftop”) #realtimechem — Penny Higgins (@paleololigo) April 18, 2013
Back to work://platform.twitter.com/widgets.js
Prevortexing. Not much sample. Single shot analysis. #realtimechem twitter.com/paleololigo/st… — Penny Higgins (@paleololigo) April 18, 2013
After vortexing. Where’d my sample go? Always a little nerve wracking. #realtimechem twitter.com/paleololigo/st… — Penny Higgins (@paleololigo) April 18, 2013
Next step: An acetic acid rinse.#realtimechem Mmm. Vinegar. twitter.com/paleololigo/st…
— Penny Higgins (@paleololigo) April 18, 2013
The acetic acid is for getting rid of extra carbonates, like calcite, which have tons of carbon and oxygen!
Anything to make pipetting more interesting! #realtimechem twitter.com/paleololigo/st…
— Penny Higgins (@paleololigo) April 18, 2013
Always label your vials in more than one place, because this can happen. #realtimechem twitter.com/paleololigo/st…
— Penny Higgins (@paleololigo) April 18, 2013
And, where possible, offer little tips for budding scientists everywhere.
When the samples are dry, they’re ready for analyses. I’ll discuss the set-up for that in another post.
I didn’t include every detail of every step in the process, but I think that a reader (or follower of the #RealTimeChem hashtag on Twitter) would get a good sense of the process that we go through to go analyses.
And I hope that all of this de-mystifies chemistry (and geochemistry) just a little bit for everyone!