LC-MS - Secondary Amines and Ammonia

Dear all,

I’ve been given a method from a 3rd party to have a look at that is giving some unusual and variable results.

Nothing in it looks too unusual from other methods I have been looking at, except that any potential nitrosamine is washed from the SPE column utilising ammonia solution!! Now this by itself seems a little unusual, as other methods have involved aqueous formic acid, or formic acid in methanol.

I am wondering if there is the potential for the formation of nitrosamines during the preparation through the use of the ammonia and the presence of chloride ions, similar to below.

Does anyone have any thoughts, or seem anything similar?

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Hi Mark!
I stumbled upon an article reporting degradation of some aniline derivatives on C18 column with ammonia/acetonitrile eluent. You may want to explore it, I have just read the summary.

There is also an article reporting on column nitrosamine formation with NH4OH containing mobile phase:


Awesome - thank you!! I will investigate this - I was starting to think that nitrosamines were finally turning me a little mad! :crazy_face:

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