Week 4 - Wednesday and Thursday

Wednesday in the lab:
We started the dialysis of our practice samples today at 9:00 am. Anna, Marie, Adama, Vieux, and I were present. As it takes at least 4 hours to travel to St. Louis, we left Vieux to finish the 2nd half of the dialysis. Anna, Marie, Adama, and I left for St. Louis Wednesday around 3:00 pm.

Thursday - The retrieval
As we were heading to the first site the pick-up decided to leak all of the water and coolant out of a fitting on the water pump about 10 miles from the site. We had to hitch a ride with what I believe was one of the driver's friends. For the rest of the retrieval we used a horse cart to travel from site to site. The retrieval was successful and all cages were still present and accounted for. Something did happen to the cages though...something i feared after taking a look at the old style cages. They had rusted. Some more than others. It seems as though the stainless used was either a bad batch or low grade. Most of the rust occurred along the welds. I will take some pictures on Monday and post them. I added one picture that kind of shows the rust.

The pickup was towed back to St. Louis and fixed relatively fast though we did have to wait several hours after the retrieval and our horse drawn carriage ride was over.

Sorry I did not post earlier, but I didn't get back to the hotel until about 9 pm.

Week 4 - Tuesday

Great news...at about 5:15 pm the oven arrived. If we ever need to bake anything out at 3000 C we are set. See picture below. I was told they will install it on Wednesday. The size is a little deceptive, it has a lot of insulation.


We are still trying to get a hold of a pesticide grade hexanes distributor. I'm not sure we can get high quality hexanes before my time is up here.

We made the stock solution for the 14 analytes with the ethyl acetate we found yesterday. I ran several injections of the ethyl acetate on the GC to make sure it was clean....it was. We decided to make some practice samples. We will use the reagent grade hexanes and see what happens. The samples are LFT that were spiked with both our PRC mix and our mix of 14 analytes. While running the ethyl acetate I noticed one peak that shows up in both detectors very consistently. It is definitely higher in the first run of the day if the GC remains idle overnight.

Wednesday we will do a dialysis of the practice samples then leave for St. Louis. We will retrieve on Thursday then head back to Dakar in the afternoon.

Week 4 - Monday

The project of the day was to track down pesticide grade hexanes in Senegal since the only grade in the lab is standard reagent grade. It looks as if there is none in Senegal. It would take at least 2 weeks to ship it, probably more since most of the companies we have contacted, including Fisher seem to take their sweet time answering inquiries. Also, the french websites are not as nicely laid out as the American ones and they are not the same product numbers, so it took a very long time to do to say the least. We did happen upon some pesticide grade ethyl acetate which will work great for standards in the mean time. Baba, Anna, and I spent a lot of time working this out so far.

We ran into a problem with the rotovaps and our glassware but found a solution. The rotovaps have a larger fitting than the round bottom flasks we shipped over previously. Adama found an adapter in a storage room and it works. The problem is that we only have one....so only one operational rotovap. This will increase blow down time unfortunately. We will search harder for another fitting. We have been steadily baking what glassware we can until the new oven arrives.

I'm still running into degradation in the inlet of our third PRC dibutylchlorendate. I re-did the liner for the front inlet, but kept the back the same to compare. It does look much better than before but the dibutylchlorendate is still a problem. Maybe we should not use it. I will be able to better evaluate the situation once we make a standard of the analytes (14 components).