[bstanley]

Hi all,

There are some molecules that can suppress the analyte signal in mass spectrometer (MS) when using electrospray ionization (ESI) as ionization process. My question is: do amine and ketone/aldehyde suppress analyte signal in electrospray (ESI) if they are present? Thank you.

B

[MOTOBALL]

You have posted a very generalised question, so I shall give you a very generalized answer...

1. Amines, being very basic, will have a very good MS response (ESI, APCI, CI) and even at a 1:1 molar ratio will likely swamp the response of a less basic compound (e.g. a ketone/aldehyde).  I would guess that you might have to inject an RNH2/RCHO mixture at the 1:100-1000 ratio to get an equal response for the [M+H]+ signals of each.

2. The same argument can be extended to a mixture of RCHO and a less basic compound

3. Experimentally, you could check for suppression by periodic injections of the RNH2 or RCHO into a continuously infused solution of the analyte of interest.
 
MOTOBALL