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- Posts: 2
- Joined: Mon Jan 28, 2019 9:31 am
I'm quite new to GCMS and on my first use I had a strange problem (strange for me).
I injected SCFA's standarts with water as a solvent. I also used formic acid in order to lowered the pH.
This protocol has been used once before at our lab few month ago and it had good results (very nice peeks) when the acetic acid was the first to be out of the column then: propionic acid, isobutyric acid, butyric acid, 2methylbutyric acid, isovaleric and valeric acid. Actually, I guess the formic acid was the first to go out but they didn't see it because the "solvent delay" option.
last week I tried to do it again and I got another picture when the acetic acid went out first, then formic acid (which masked the propionic, isobutyric and the isobutyric acid) and then I saw the peeks of the rest (2methylbutyric acid, isovaleric and valeric acid)
It's reasonable to think that formic acid will go out first from the column and it doesn't happen, I spent a whole day trying change the settings.
Any idea's
TNX
Settings: https://drive.google.com/drive/u/0/folders/1jr7YRm6vRDgLgE9MPojuRlfFKmdzlXel