Hello all!
I am trying to develop an LC–MS/MS method for N‑nitroso‑ambroxol, but I am facing a recurring problem: I only observe the intact ambroxol ion, with no evidence of the nitrosated ion under any conditions tested. I have already varied source temperature and fragmentation energy, tested different mobile phases, several additives (both acidic and basic), and even other ionization conditions, but there is still no consistent signal for the nitrosated species.
This raises a fundamental question: Is N‑nitroso‑ambroxol actually stable enough to be detected by LC–MS?
Or does it simply decompose rapidly (e.g., by losing NO and reverting to the ambroxol m/z)?
I would like to ask the community: Has anyone ever attempted to analyze N‑nitroso‑ambroxol? Did you encounter similar difficulties? Was the nitrosated standard stable at all? What strategies worked (or did not work) for you? Is there any viable alternative if the nitrosated species is not stable for ESI analysis? (I have also tested APCI without success.)
Any insight, practical experience, or suggestions would be greatly appreciated.