Advanced Polymer Characterization: Modular Operations for Spectral Alignment by Iterative Compression (MOSAIC)

Matrix-assisted
laser desorption/ionization (MALDI) mass spectrometry
encodes structural information across diverse homo- and copolymer
ensembles, yet decrypting these spectra requires a systematic analytical
approach. We introduce Modular Operations for Spectral Alignment by
Iterative Compression (MOSAIC)a general cipher algorithm that
applies modular arithmetic to filter monomer-derived mass contributions
and cluster MALDI peaks by nonconstitutional repeating units (non-CRUs).
MOSAIC performs sequential modular operations using monomer mass differences
as base units to compress complex spectral data, revealing end-group
distributions and comonomer incorporation. As a demonstration, we
applied MOSAIC to five copolymers formed by two different polymerization
mechanisms. The resulting remainder–mass plots clearly resolve
polymer homologs with distinct non-CRUs into visually apparent clusters,
enabling intuitive assignment of mass spectral features.