I arrived at CERES around 8AM and left at 4:30PM.
Inspection of the instrument
revealed that the detector baselines did stabilize, however both were significantly higher than before! Front = 870 +/- 1 Hz, Back = 1920 +/- 2.5 Hz.
They were previously around 650 and 1200 Hz. I decided to run blanks to
evaluate the baseline over the run. They both looked really cruddy… high
baselines, continuous large saw tooth pattern, random systematic signal dips,
and a step up and back down 2/3 of the way into the run. See below.
Front Detector - n-Hexane Blank
Back detector - n-Hexane blank
Everything that I’ve been reading points to
low purity gases, saturated gas purifiers, and worn-out detectors; it wouldn’t
surprise me if CERES has all three working together against them. Anna and I
discussed this, I suggested she contact a technician, and she subsequently scheduled an appointment with a local
Senegalese technician from a company called Technical House (not sure of the
spelling). She told me that they will be here tomorrow morning, though not sure
what time – they said that they would call and let us know tomorrow… Instrumental
analysis continues to be on hold until instrument capability has been restored.
In spite of this set back, I’m
still finding plenty of things to work on with CERES staff. For instance, I
looked over the post deployment cleaning bench sheets that CERES should have
filled out during the execution of the process before my arrival. However, no
information was filled in for:
1) The
chemists that performed the activity
2) Completion
date and initials
3) Solvents
used (i.e. Isopropanol and HCl)
4) Chemist
review signature and date
I
had Anna fill in the information right then and there and again communicated
the importance of keeping tidy notes and completing project documentation for
ease of reference later on in the project. I also helped Ann with some
injection port maintenenace on CERES’ GC-MS. She handled new injection port
liners with her bare hands, set them down on non-cleaned surfaces, and packed
them with way too much wool using a pair of large tweezers – less than ideal.
So I used the opportunity to discuss the importance of maintaining clean liners
for achieving low baselines, showed her how to use a glass wool packing tool,
and how to use acetone on a swab to clean out the injection port. I helped Anna
organize GC tools and components into a small tool box for ease of locating.
Also, I assembled a list of solvents used in this study and included chemical
company name and purities for Kim Anderson (OSU).
2 comments:
Training required repeation even under the best of circumstances. From the training at OSU with Anna:
Research Chemist, Glenn Wilson, performed training on additional instrument maintenance. This included reviewing standard operating procedures, demonstrating the techniques and practices and then letting Anna have hands-on practice. The following procedures were covers:
• GC liner changes,
• GC cleaning of injection system.
Also Glenn provided training on the application of solvent blanks to method these concepts were presented, discussed and reviewed.
Of course clean contaminant free techniques were illustrated and required.
Norman,
Did you communciate with Anna that filling out paperwork weeks after something has been done defeats the purpose of accountability and tracability? It is not just an "OSU tidy thing", it is required by any accrediating field, there simply is no validity to this kind of documentation process.
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