Automated MALDI-TOF-MS sample preparation in combinatorial polymer research

A new automated matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) sample spotting technique that allows the integration of MALDI sample preparation in the workflow of combinatorial polymer research is described. The technique is performed utilizing a commercially available synthetic robot and was first evaluated with polymer standards of known composition and later on used for the monitoring of the living cationic ring-opening polymerization of 2-ethyl-2-oxazoline. The spotting was carried out as a multiple layer approach, which offers the ability of complex sample preparation without the requirement of premixing the different components. The described technique reduces the time required for sample preparation and offers the possibility of automated sample spotting during polymerization reactions performed in a synthetic robot. This allows the integration of molecular weight screening and polymer end/group determination utilizing MALDI-TOF-MS as a high-throughput tool in combinatorial polymer research.