Accurate end group determination of low molecular weight polymers by electrospray ionization time-of-flight mass spectrometry

A method is described for the identification of monomers and end groups in low molecular weight synthetic polymers using electrospray ionization and an orthogonal accelerated time-of-flight mass spectrometer. Thanks to the high mass accuracy the elemental composition of the monomer and end group of an unknown alkylated poly(ethylene oxide) was determined with an error of 1 mDa. The present method compares well with literature data for polymer characterization by Fourier transform ion cyclotron resonance mass spectrometry and might be a simple alternative provided that the inherent lower resolution is not critical.