Insights into the fragmentation pathways of gas-phase protonated sulfoserine

- The CID fragmentation pathway of protonated sulfoserine was investigated.
- The two dominant fragment ions resulted from loss of SO3 and H2SO4.
- The SO3-loss ion was found to be structurally analogous to protonated serine.
- The H2SO4-loss ion was assigned an aziridine structure as its major constituent.