An attempt at end-group analysis of polycarbonates up to 100,000 molecular weight using SEC preparative separation and NewSpiralTOF™
MSTips No. 527
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) is a powerful tool for characterizing synthetic polymers, including confirming molecular weight distribution and estimating end group composition, because it can detect monovalent ions over a wide mass range. However, in the analysis of polymers with high polydispersity, "mass discrimination," where ionic intensity decreases in the high molecular weight range, is a challenge. To overcome this challenge, it is known that fractionating polymers according to molecular weight using size exclusion chromatography (SEC) to reduce polydispersity before measurement with MALDI-TOFMS is effective. Generally, low-resolution linear TOF is often used for measuring synthetic polymers with molecular weights exceeding 10,000, but its low mass accuracy makes it unsuitable for end group composition estimation. In this report, we attempted end group analysis using high-precision MALDI-TOFMS after SEC fractionation of polycarbonate (PC) with high polydispersity.