UPLC mobile phase with pH above 10
Posted: Thu Oct 20, 2011 6:30 pm
Hi,
I am using a mobile phase A (80% of acetonetrile, 10 mM ammonium formate) and B (50% of acetonitrile, 10 mM ammonium formate). The pH of mobile phase was adjusted to around pH 10 with ammonium hydroxide (need a lot of ammonium hydroxide). the preliminary data looks promising. But I worry about the the amount of ammonium hydroxide there. will it be stable (or evaporated out)? the separation of targets compounds favor high pH and high buffer concentration. Should I use higher salt concentration (15mM) and lower pH (around 9) to minimize the amount of ammonium hydroxide? Thanks for any suggestions?
I am using a mobile phase A (80% of acetonetrile, 10 mM ammonium formate) and B (50% of acetonitrile, 10 mM ammonium formate). The pH of mobile phase was adjusted to around pH 10 with ammonium hydroxide (need a lot of ammonium hydroxide). the preliminary data looks promising. But I worry about the the amount of ammonium hydroxide there. will it be stable (or evaporated out)? the separation of targets compounds favor high pH and high buffer concentration. Should I use higher salt concentration (15mM) and lower pH (around 9) to minimize the amount of ammonium hydroxide? Thanks for any suggestions?