Prilates

[totosr]

Hi,

We are trying to quantitate Pril/Prilates from human plasma.
Our problem is that the sensitivity for Prilat is much much lover than that of Pril. (Enalapril/Perindopril/Ramipril/Quinalapril).
We are using positive ESI with MS/MS detection, MeOH/H2O with 2.5 mM Ammonium Formate in mobile phase. We have varied the MeOH / H2O ratio
from 91/10 to 45/55, but no significant reponse enhancement, only better separation at lower Methanol ratio.
Also tried in negative ESI but no response.

If any of you has an idea for a better method please help.

Best Regards,

TR

[sam.pedraglio]

I've never faced these cmpd's but, based on the structure, have you tryed to work with basic mobile phases and negative ionisation? I'm thinking to NH4HCO3 10mM/MeOH.