Maldi time-of-flight mass spectrometry of synthetic polymers

TLDR

Mass spectrometry of intact synthetic polymers has historically been limited to field desorption, but recent advances in soft ionization techniques such as ESI and MALDI combined with time‑of‑flight analyzers have expanded the field, enabling characterization of a wide range of polymers while still facing challenges with halogenated polymers, polyolefines, copolymers, blends, and block‑copolymer sequencing. This review focuses on MALDI time‑of‑flight mass spectrometry for polymers. Reliable MALDI‑TOF spectra require careful choice of matrix, cationization salt, and sample preparation, and hyphenated methods such as SEC/MALDI have been introduced to address mass discrimination. Even with optimized conditions, mass discrimination can occur when analyzing polydisperse polymers, limiting oligomer discrimination. © 1999 John Wiley & Sons, Inc., Mass Spec Rev 18: 309–344.

Abstract

Mass spectrometry of intact synthetic polymers has been limited to field desorption (FD) MS for many years. More recently, soft ionization techniques such as electrospray (ESI) and matrix-assisted laser desorption/ionization (MALDI) and the revival of time-of-flight analyzers created new opportunities for the characterization of polymers. In this review emphasis is put on MALDI time-of-flight mass spectrometry of polymers. The selection of an appropriate MALDI matrix, cationization salt and sample preparation techniques are critical success factors for obtaining a reliable mass spectrum and to infer structural information such as monomer mass(es) and end-groups. However even under optimized conditions mass discrimination in the analysis of polydisperse polymers and specific oligomer discrimination might occur. Hence hyphenated techniques such as size exclusion chromatography (SEC)/MALDI have been developed. Many different polymer applications appeared in recent literature, but most studies deal with homopolymers. Many challenges remain, particularly in the fields of halogenated polymers, polyolefines, copolymers, blends, and in the sequencing of block-copolymers. © 1999 John Wiley & Sons, Inc., Mass Spec Rev 18: 309–344, 1999