The sample extractions were started first thing in the morning (~8:00 am). Adama and Anna added 100 mL of hexanes to the samples and prepared a reagent blank and lab OC pesticide spike. The OCP spike consisted of 200uL of a 1,000 ppb concentration standard prepared from the Chemservice OC pesticide standard OSU provided. Adama, Marie, Anna, and Sokhna worked on the second dialysis.
Dialysis of retrieved PSDs.
Cheikh ran the standards on the GC using the OSU methods. Results should be available Friday.
A review of the field bench sheets revealed substantial deviations, mostly in the form of unrecorded data. I discussed this with Cheikh and we will work with the staff on the next retrieval to increase completion.
Oct. 5th 2007
The standards finished without incident on the GC but there was not time for anything but a cursory review of the runs. Background was low, many of the 5 ppb peaks were identified, but specifics will not be available until Monday at the earliest, possibly Wednesday due to the field work at
Today Locustox performed the sample blow down on Rotavaps and the Techne Dri-block. In attendance: Adama, Marie, Sokhna and Cheikh.
Transfer from round bottom flask to smaller tube.
One sample, the trip blank, became contaminated with water on the Rotavap blow down. We used it as an example on how to remove water from a sample and where to keep accurate notes on the bench sheet.
After the extraction the samples were loaded onto the GC with the standards for analysis over the weekend.
4 comments:
How many rotavaps are available? I am looking down the road when we will need to be extracting samples via batches, not 1 or 2 at a time. What about a evap/recovery system here, would it work? Curious is hazardous waste an issue?
The half way point, deep breath all. You have one more set of field samples to collect, yes? (fyi, week six in review)
What was the follow-up on the update of chemstation, (your version), and uploading it on a laboratory computer?
There are three Rotavaps already up and running, and a couple more in storage. They have a vacuum pump and chiller for the Rotavaps, which are considerable newer than our units. They work extremely well.
The Techne Dri-block worked fine, but cannot hold half as many samples as a TurboVap LV (which can hold 50).
We are at the half way mark, but we have two more sets of field samples to collect. Tuesday we collect the Locustox/OSU duplicates, then another set the following week.
The update of Chemstation was unsuccessful on my computer. I'm still not sure what happened. The diagnostic check says the install is good, the license is good, but it shuts down immediately after start up. I'm still trouble shooting.
This newest version of Chemstation has changed the interface substantially. The look of the reports and chromatograms are the same, but menus and sidebars are quite different. It's taking me some time to get used to it.
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