Effect of combined changes in delayed extraction time and potential gradient on the mass resolution and ion discrimination in the analysis of polydisperse polymers and polymer blends by delayed extraction matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

Data reported here show that, in the delayed extraction matrix-assisted laser desorption/ionization time-of-flight (DE-MALDI-TOF) mass spectrometric analysis of synthetic polydisperse polymers, different experimental conditions of spectral recording are required to optimize the signal in all the m/z regions of the spectrum. The effect of combined changes in delay time and grid voltage % values on both mass resolution and mass accuracy of DE spectra of a polyethylene glycol sample (PEG(mix), with a well-defined molar distribution of its components) is discussed. The necessity of a compromise between the values of these two parameters is shown. Furthermore, the occurrence of analyte discrimination, which can invalidate the composition analysis especially in the case of polymer blends, is demonstrated. Copyright 1999 John Wiley & Sons, Ltd.