Chapter Eight: Weighing Dirt Is Hard, Man (feat. Melanie, Jeff, Jamie, Bryden, Sabrina)

Remember a few posts ago, where I said that I was really bad at keeping my hand steady? Remind me to eat well so that I don't shake when I'm creating microwave acid digestion bombs.

Let me explain: no, I didn't burn myself with acid. This week, I did some digestion prep for soil and sediment samples - I spilled dirt, nothing serious.

Being able to do this part of the process was especially interesting because I've already cleaned digestion tubes after the actual digestion and testing! Here's how digestion works:

First we load up about 2 milligrams of each soil sample into these tubes (which caused quite a mess) so that it'll be easier...

To load about 0.4 milligrams of the samples into the microwave "bombs." They're not actually bombs, but they are incredibly pressured, so the name sticks.

We add the sample into the bombs...

and add some different concentrations of acids...

that we need to be precise with, so we have this here auto-pipette!

The acids, however, produce toxic fumes, so we keep them under a fume hood.

Using this tool to tighten the bombs into their holders...

Using this spin-wheel, we insert the bombs into the microwave, where they get heated and pressurized, causing the soil to break down into liquid.

After transferring the dissolved soil into new tubes, we clean the bombs with distilled water and dunk them in this nitric acid bath.

After all of this is done, we'll run the liquid through this machine...

Which blocks out every wavelength of light except for the wavelength of a particular ion. We run the samples through the machine, and the change in the light intensity is measured.

 And that's essentially digestion! Besides that, I've worked on NAS trays. I'm also still waiting to hear back from that professor, so I'll hopefully have that in next week's post. Additionally, Jeff ran my samples through a denitrification machine to get another reading on how much nitrate is in my sample! He's yet to compile the results, so that'll also hopefully be in next week's post.

Thanks for reading! Remember that the day of Senior Research Project presentations is May 6th, from 9-4:30 (or so). Mark that date on your calendar!

End of Chapter Eight.