Determining the time needed for the vortex method for preparing solvent-free MALDI samples of low molecular mass polymers.

Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry is an important technique to characterize many different materials, including synthetic polymers. MALDI mass spectral data is used to determine the polymer average molecular weights, repeat units, and end groups. The development of the vortex method of solvent-free sample preparation showed that remarkably short mixing times could prepare samples that yielded high quality MALDI mass spectra.

Imaging the morphology of solvent-free prepared MALDI samples.

Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry is an important technique to characterize many different materials, including synthetic polymers. MALDI mass spectral data can be used to determine the polymer average molecular weights, repeat units, and end groups. The development of solvent-free sample preparation methods has enabled MALDI to analyze insoluble materials and, interestingly, can provide higher-quality mass spectral data.

Investigations of electrospray sample deposition for polymer MALDI mass spectrometry.

In the interest of a more thorough understanding of the relationship between sample deposition technique and the quality of data obtained using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry, details of the electrospray (ES) process of sample deposition are investigated using a number of techniques. Sample morphology was observed with scanning electron microscopy (SEM) and atomic force microscopy (AFM), while matrix-enhanced secondary ion mass spectrometry (MESIMS) monitored surface coverage. Electrospray deposition reduces the analyte segregation that can occur during traditional dried droplet deposition for MALDI.