Poly(2-hydroxyethyl methacrylate) (poly(HEMA)) has been characterised by means of electrospray ionisation-mass spectrometry/mass spectrometry (ESI-MS/MS), in order to evaluate this technique for the generation of end group information. Low energy collision-induced dissociation (CID) data from poly(HEMA) enabled information on both end groups of the polymer chain to be gleaned, in a similar fashion to that proposed previously for other methacrylate polymer systems. Exact-mass CID information was employed to aid the understanding of the dissociation mechanism of the polymer Some additional fragmentation pathways, compared to other methacrylate polymer systems, are proposed. An example of how software can aid the interpretation of the MS/MS data is also shown (C) 2010 Elsevier Ltd All rights reserved.