By Anonymous on Thursday, March 4, 2004 - 02:55 am:
Dear all,
Can anybody give some suggestion or Reference(s) about LCMS anlaysis of Pyrimidine base related compounds. We have observed only the M+ not M+1 or M+18 in our analysis.
Is all the pyrimdine related compounds give M+ only?
Advance thanks.
By MG on Thursday, March 4, 2004 - 06:33 am:
I don't know your structure, so first check to see if your compound isn't already pre-charged, like a quaternary amine. If it's pre-charged, you'll just see the cation without a proton adduct. (If it did form a proton adduct, it would be doubly charged in that case).
If that doesn't answer the question, there are two other possibilities. (1) You are making a radical ion, which is rare with ESI or APCI. (2) Your mass calibration is off.