What Does the '+1' Signify in Mass Spectrometry Notation?

[Lindsayyyy]

Hi everybody,

I'm new to the subject and I'm having a question. I have a MS of peptide fragments. I just learned about a,b,c ions etc. In my diagram it shows only b ions. I don't understand the following:
On one peak it says b5 -H2O+1

I understand it this way: It's the mass of the b5 ion plus the mass of one h2o molecule (~18u). Is that correct? Or in other words: What does the +1 at the end mean after the H2O?

If I'm in the wrong forum for this I'm sorry.

Thanks for your help in advance.

Regards lindsayyyy

 

[Zefram]

Hi lindsayyyy,

Welcome to the subject! The +1 at the end of the notation indicates the charge of the ion. In mass spectrometry, peptide fragments are typically ionized, meaning they have gained or lost one or more electrons, giving them a positive or negative charge. In this case, the b5 ion has lost one hydrogen ion (H+) and one water molecule (H2O), resulting in a +1 charge. This notation is used to indicate the mass and charge of the ion, which is important for identifying and analyzing peptide fragments.

I hope this helps clarify things for you. Don't hesitate to ask any other questions you may have. Happy researching!