Fragmentation at 4.9 mz January 15, 2018, 02:02:05 AM Dear Forum members, My MS1 files are showing multiple fragments at 26 mz apart with a strong base peak in between them. The more fragmented MS2 (I mean MSe here since this isn't MSMS) files are then showing the same peaks shifted by 4.9 mz each backwards. Any idea what this may be? Quote Selected
Re: Fragmentation at 4.9 mz Reply #1 – January 15, 2018, 02:19:15 AM 4.9554 could be a Na+<-> NH4+ difference. https://github.com/stanstrup/commonMZ/blob/master/inst/extdata/adducts_fragments.tsv26 I don't have a good idea for. What is it accurately? Quote Selected
Re: Fragmentation at 4.9 mz Reply #2 – January 15, 2018, 05:12:08 AM Hi Jan, Yes, I did think NH4 to Na made sense, but it would occur at least three times in a row. The 26 difference is 26.0225, also at least 3 times in a row...And why would it all be shifted by 5 mz between MS1 and MS2? Quote Selected Last Edit: January 15, 2018, 05:14:20 AM by ab123
Topic: Fragmentation at 4.9 mz