Week 6 - Monday

The 1st retrieval samples ran over the weekend on the GC.

GC training was done with Anna mostly (Adama, Marie, and Vieux were watching, but were also in and out). We processed the front column chromatograms and looked at the standards we ran with the samples. While viewing and processing the QC samples it was obvious that there was a cross contamination (of most of the analytes in our method) issue happening, which is unfortunate. The worst sample was probably the reagent blank, which during the dialysis was the last sample to be transferred and processed to see if we had cross contamination.

Part of the day was spent trying to track down where this contamination occurred. There was a centrifuge tube that had hexanes in it that was in the blow down module that had been exposed to the air in the lab for ~1 week and we ran that and found no peaks that were identifiable, so the contamination is probably not coming from the ambient air. I had previously not seen any contamination with solvent blown down on the rotovap, so that is likely not the source.

We made 4 blank LFT and set them up in the hood, bench top, freezer, and LFT construction rig to see a worse case scenario. If we see nothing in these samples then I don't really know where the contamination came from. If you have any ideas please post them as a comment to this post.

Tuesday I hope to prepare and run samples from the 2nd retrieval. We will also finish updating the the calibration curve for the back column and hopefully finish analyzing chromatograms so we can start looking at the calculation spreadsheet.