Utilising time-lag focusing ultraviolet-matrix-assisted laser desorption/ionisation-mass spectrometry for the end group analysis of synthetic polymers

Time-lag focusing matrix-assisted laser desorption/ionisation-mass spectrometry (MALDI-MS) has been employed to analyse synthetic polymers with average molecular weights between approximately 3500 and 12500 Da. Spectra are shown that demonstrate the improvement in resolution and sensitivity when time-lag focusing is used instead of prompt extraction techniques. A resolution of almost 9000 (FWHM) was obtained, in the reflectron mode of operation, for a poly(methyl methacrylate) (PMMA) sample with a relatively narrow dispersion. The data for PMMA polymers of industrial relevance easily enables the differentiation of many end groups as a consequence of the improved signal-to-noise and good mass accuracy when time-lag focusing is employed.