GPC separation of polymer samples for MALDI analysis

Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry is an important technique to characterize the average molecular weights, oligome r repeat units, and end groups of polymer materials. Although MALDI methods have been developed for a broad variety of different synthetic polymers, M ALDI continues to struggle with polymer samples having broad polydispersity (PD). We have combined MALDI and gel permeation chromatography (GPC) analy ses for broad PD polymer samples with the use of a liquid chromatography (L C) interface. The LC interface uses heated sheath gas and a capillary nozzl e to remove most of the mobile phase and deposit the GPC eluants on the pre coated matrix on a moving MALDI plate. Our experiments demonstrate that the combination of GPC-LC interface-MALDI can aid in the characterization of b road PD samples, the verification of the presence of low-intensity, high-ma ss oligomers, and the detection of minor series in polymer samples.