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- Posts: 9
- Joined: Wed May 31, 2017 11:10 am
I'm having some trouble with my HPLC runs:
I'm getting some ghost peaks (2 or 3) in almost every injection with the same intensity.
I get it with samples, blanks and no-injection runs.
Even though I'm using a gradient (H2O + 0,1% TFA : Acetonitrile; actually I'm running with different gradients, e.g. 10%AcN -> 95% AcN or 40% AcN -> 90% AcN), it is NOT due to solvent mixtures since it started appearing some days ago (and have plenty of previous runs with the same method without these peaks).
Im using a Phenomenex Luna C18 (5um)
I tried several things:
Preparing new mobile phase (problem persists)
Preparing mobile phase without TFA (problem persists)
Changing pre-column (problem persists)
Changing column (same column, problem persists)
Running with no column and pre-column (NO PEAKS)
Running with no column (NO PEAKS)
To my eyes, everything points out to be something precipitated in the column, but when I changed it for another one with the same specifications and got the same results I just couldn't believe it.
Any other suggestion?
What can it be?
Thanks in advance!