[kamiyu]

I got the results of HRMS and I found there are two peaks above molecular ions, which is M+16 and M+28

I asked the staff doing the HRMS and I was told this can be normal due to atmospheric contaminant. This may not suggest my sample is not pure (My sample is NMR very pure)

Any comment??


Fortunately, the staff comments the result can be used for publication

[Corribus]

It's all relative of course but NMR is not a particularly good indicator of purity. Other techniques may be more sensitive to impurities that do not show up in an NMR sample.

[MOTOBALL]

Which MS method was used ?

[kamiyu]

Seems to be ESI

This time I observe dimeric ion in MS.

[MOTOBALL]

Can you be more specific about the ESI method, i.e., what was the sample dissolved in and what was the mobile phase.  M+16 and M+28 are not normal adduct ions.