Improvement of Kendrick Mass Defect (KMD) Analysis to Accelerate the Polymer Characterization by High-resolution Mass Spectrometry

High-resolution mass spectrometry is a powerful method for the characterization of polymer materials, but the resulting complex mass spectra bring with it the difficulty of data analysis. Kendrick mass defect (KMD) analysis, which converts complex but informative mass spectra into a two-dimensional plot, can visualize the distribution of multiple components, and has recently attracted attention as a practical polymer characterization technique. Conventional KMD analysis is still insufficient for analysis of industrial polymer materials with complex compositions, so we have proposed several advanced KMD analysis techniques, such as resolution-enhanced KMD (RE-KMD) and remainder of KM (RKM). Sample pretreatment methods have been further developed to observe high quality matrix-assisted laser desorption ionization (MALDI) mass spectra suitable for the KMD analysis. The KMD analyses have been further expanded to other mass spectrometric techniques such as electrospray ionization (ESI)-MS, direct analysis in real time (DART)-MS, and pyrolysis-GC-MS. These achievements are expected to accelerate polymer characterization using high-resolution mass spectrometry.