Dear members,
Using LC-MS, I have a complex sample to separation. According reference materials, part of it compostion is easy to ionize in ESI and rest compostions easy in APCI. Could I expect complete the analysis in APCI. In another words, could I ionize those compounds in APCI which is easy to ionize in ESI?
Thank you in advance.
Michelle

Dear Michelle

You have to try it in your lab.

A general answer cannot be given - if it always was possible to ionize "ESI-compounds" in APCI-mode, then why would anyone buy ESI?

Of course there is a possibility, that you can ionize your compounds with APCI, but only trial (and error?) will tell you.

I agree with Thomas. Some compounds that work readily by ESI, will degrade in the hotter APCI source. Others will work well either way, so it is worth a try.

Thank you, dear friends!
Michelle