MALDI Mass Spectrometry of Synthetic Polymers

This paper reviews the application of matrixassisted laser desorption/ionization mass spectrometry (MALDI-MS) to the analysis of synthetic polymers, and includes data obtained by Toyota CRDL. In MALDI-MS of synthetic polymers, the selection of a matrix and cationizing agent, as well as the sample preparation techniques, are very important to obtaining a successful spectrum. MALDI-MS makes it possible to measure the absolute molecular weight and molecular weight distribution of synthetic polymers having narrow polydispersity. For most synthetic polymers with wide polydispersity, on the other hand, a technique combining size-exclusion chromatography and MALDI-MS has been proposed to determine the absolute molecular weight distribution in order to overcome the problem with mass discrimination whereby the high molecular weight components are hard to detect, such that the molecular weight distribution cannot be obtained accurately. Additionally, MALDI-MS makes it possible to characterize the molecular structure of the products of degradation caused by light or heat, as well as insoluble samples such as polycyclic aromatic hydrocarbon. It is expected that MALDI-MS will significantly contribute to the progress of materials development and degradation analysis. We believe that many interesting avenues of research remain unexplored in the field of MALDI-MS of synthetic polymers. These include the search of a universal matrix that can ionize any synthetic polymers, sample preparation techniques, and so on.