Structural characterization of polymethoxymethylsiloxanes by electrospray ionization tandem mass spectrometry

- CID of ammoniated polymethoxymethylsiloxane (PMMS) was studied to propose MS/MS rules.
- In the high mass range, PMMS eliminated CH2O/CH4 neutrals in an iterative manner.
- In the low mass range, cleavage of SiO bond generated product ions containing one end-group.
- The number of CH2O/CH4 losses provided the polymerization degree of the precursor.
- The end-group characterization allowed unique insights into the synthesis route.