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- Posts: 185
- Joined: Fri Jul 20, 2012 9:18 am
another update in the odor-story.
I was trying to add 246_Tribromoanisole to our routine methode. When injecting (SPME) a high standard simply spiked in mQ there is no problem detecting it. but when I apply the regular sample prep I can't find 246TBA anymore.
I managed to trace the problem to the 25µl 1M NaOH that is added to 10ml of sample in order to get a better peak chape for 2-MIB.
Apparently 246TBA breaks down, or is unable to be trapped on SPME when the pH is high.
On the image below you can see:
-> a 246TBA standard in the presence of NaOH
-> the same 246 TBA standard without NaOH
-> a mass spectrum of the peak at 15.69min in chromatogram 1 (this is not 246TBA)
-> a mass spectrum of the peak at 15.76min in chromatogram 2 (this is 246TBA)
please note that the scaling is different for both peaks.
Can anyone explain to me why I don't see this effect with 246-Trichloranisole? I'm perfectly able to see TCA at 0.02-0.05ng/l and the 246TBA peaks shown above are about 10-20ng/l.