-
- Posts: 54
- Joined: Sat Apr 21, 2007 5:17 pm
Hello everyone
Ihave astrange problem in method development and I hope finding who has an experience to help me solving it.
I work on eztimibe method development on mass spectrometry on API4000 (Applied Biosystem) for bioequivalence studies
And I use D4-Eztimibe as Internal standard
My mobile phase (80%Methanol+0.1%FA) and (20%H2O+0.1%FA)
I use different columns Phenomenex Synergi MAX, Fusion, LunaC18 (2), ordinary C18 all with 50mm long and I try C18 150 mm
I try Acetoinitrile instead of methanol and I use Ammonium acetate buffer as another option instead of water
My ionization is ESI MRM -ve
408-271for drug and 412-271 for IS
I investigate all sources of contaminations and try to avoid it
Now the Question
Why when i inject blank iget interference peak at retintion time of eztimibe and i didnt get it D4-eztimibe although they have same daughter ion
I dont have carry over because injection of water,acn,meoh give me clean
chromatogram
Ihave astrange problem in method development and I hope finding who has an experience to help me solving it.
I work on eztimibe method development on mass spectrometry on API4000 (Applied Biosystem) for bioequivalence studies
And I use D4-Eztimibe as Internal standard
My mobile phase (80%Methanol+0.1%FA) and (20%H2O+0.1%FA)
I use different columns Phenomenex Synergi MAX, Fusion, LunaC18 (2), ordinary C18 all with 50mm long and I try C18 150 mm
I try Acetoinitrile instead of methanol and I use Ammonium acetate buffer as another option instead of water
My ionization is ESI MRM -ve
408-271for drug and 412-271 for IS
I investigate all sources of contaminations and try to avoid it
Now the Question
Why when i inject blank iget interference peak at retintion time of eztimibe and i didnt get it D4-eztimibe although they have same daughter ion
I dont have carry over because injection of water,acn,meoh give me clean
chromatogram
