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Mobil 3309 by GC/MS

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Good morning everyone. I'm not quite sure this belongs in the "repair section" but... here we go. As I'm sure many of you have seen by my relentless posts on the topic, I've been in transmission fluid land for the last couple days. I am a medical technology student but to pay the mortgage I am a gas chromatography mass spectrometry (GC/MS) analyst. So logically I had to analyze some clean Mobil 3309 by GC/MS of course!

I was mostly interested in the additive package but unfortunately I was unable to identify any compounds of interest amidst the hydrocarbon background. Not wanting the work I've done go to waste I though I'd share with you the "total ion" chromatogram of the fluid. Attached is that image. The peaks with the red arrows indicate internal standards that we used to help quantify compounds in the solution so they aren't actually part of the fluid. I analyzed this sample for "tentatively identified compounds " which are compounds that we don't have standards for or don't look for regularly. While this didn't produce anything I would be comfortable reporting on a day to day basis the only thing that I identified was a compound known as trans-4'-Amino-4-(dimethylamino)chalcone (don't worry it doesn't mean anything to me either) with a 72% match labeled with the green arrow. We normally want to see matches in the 80% range. I feel the match was brought down by coeluting hydrocarbons so I'm fairly comfortable that this may actually be in the sample. 

As far as the total ion to me this looks pretty much like motor oil but seems to be tuned for specific hydrocarbon ranges (the larger and more complex the hydrocarbon the farther to the right it will be) as the response drops off suddenly after that last internal standard. To see what I'm talking about just google "motor oil chromatogram". Maybe if I have time I'll run the old stuff too. This was a 1:100 dilution by the way (fairly high to protect the instrument).

Anyway I thought it'd be fun to share becasue... science.

mobil 3309 edited.png

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