Week 6: HPLCs are Terribly Finicky Machines

I completely forgot about this week's blog entry! I can't believe it's already Tuesday and I'm just now writing Week 6's blog. My apologies for the belated update. 

I started out the week running samples on the HPLC from the T=0 (where T is time) sediment sample that I'd prepped last week. I ran samples all of Monday.

One week prior to Tuesday we'd gotten sediment samples from JP and we put them in tubes to be stored at 5 different temperatures: -80, -22, 4, 15, and 25 degrees Celcius. There were two sets to tubes, one to be stored for 1 week and another to be stored for 1 month. Tuesday marked the 1 week point so we took out our samples from the various freezers and storage places. We were going to run tests on TNT as well as 2-CAP and two other dyes, but we needed more sediment for the 2-CAP sampling than was available, so I combined the sediment tubes that were meant for TNT and 2-CAP together into small, brown, glass bottles in the glovebox and sealed them (so they would be anaerobic). I then spiked each of the 5 bottles (one from each temperature) with 2-CAP.

After spiking each bottle, I shook them for about a minute then took samples from each, and this would be the time 0 samples. I put each sample in a microfuge tube, centrifuged it, took the supernatant, and filtered the supernatant into a different microfuge tube to either be kept in the fridge (until the HPLC decided to work again) or analyzed by HPLC right away. I repeated this procedure at times 1 hour and 2 hours. Dimin took the 4 and 7 hour samples while I took another 22 hour sample the next day. 

On Wednesday I tried to run the HPLC again but I wasn't giving very good results (too long retention times and peak trailing for 2-CAP) so Dimin had to spend the rest of the day fixing the HPLC. I really can't imagine Dimin likes the HPLC very much, seeing as how he has to fix it all the time. I wish I could help him when he has to but there's really nothing I can do since I know so little about the machine. It's working now, so I can only hope with fingers crossed that it continues to be good. 

Thursday and Friday the HPLC seemed to be behaving itself, so I spent both days running more samples. Dimin and I ended up taking quite a few samples and getting pretty good at the sampling procedure. We ended up taking samples at 30 hours, 45 hours, 54 hours, 69 hours, 97 hours, 121 hours, and finally 144 hours. That's a lot of samples to analyze! But as long as the HPLC works, at least I'll have work to do. Until next week then! I'll try to update much sooner than I did this week.