Utilizing time-lag focusing matrix-assisted laser desorption/ionization mass spectrometry for the end group analysis of synthetic polymers

Time-lag focusing matrix-assisted laser desorption/ionization mass spectrometry has been employed to analyse synthetic polymers with average molecular weights between approximately 3500 and 12 500 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 (full width at half maximum) was obtained, in the reflectron mode of operation, for a poly(methyl methacrylate) (PMMA) sample with a relatively narrow range of molecular weights. The data for PMMA polymers of industrial relevance easily enable the differentiation of many end groups as a consequence of the improved signal-to-noise ratio and the good mass accuracy when time-lag focusing is employed.