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 spe ctrometry has been employed to analyse synthetic polymers with average molecular weights between approximately 3500 and 12 500 Da. Spectra a re shown that demonstrate the improvement in resolution and sensitivit y when time-lag focusing is used instead of prompt extraction techniqu es, A resolution of almost 9000 (full width at half maximum) was obtai ned, in the reflectron mode of operation, for a poly(methyl methacryla te) (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 si gnal-to-noise ratio and the good mass accuracy when time-lag focusing is employed. (C) 1997 by John Whey & Sons, Ltd.