MALDI PSD of low molecular weight ethoxylated polymers

Abstract

Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry has become an important technique to characterize the chemical structure of industrial polymer materials. MALDI methods have been developed to address a broad variety of different polymer materials, containing different chemistries. One of the key aspects of the typical MALDI experiment is the generation of intact molecular ions. The development of MALDI post-source decay (PSD) techniques has opened a new method to obtain chemical structure information from MALDI experiments. PSD provides an accessible MALDI MS/MS experiment that can be done on most commercial time-of-flight (TOF) reflectron instruments. MALDI PSD techniques have been successfully applied to a variety of synthetic polymers. This work explores the applicability of MALDI PSD methods to relatively low molecular weight ethoxylated surfactants. In these experiments, we show the PSD fragmentation mass spectra of some ethoxylated surfactants, explore the mechanisms for the fragmentations, investigate the effect of different alkali cations, and compare the fragments from isobaric surfactant molecules.