Visualizing fragmentation channels of polyethylene oxide with different end groups using the JMS-S3000 SpiralTOFTM with TOF–TOF option
Tandem mass spectrometry is a powerful tool for polymer characterization. It can obtain information about polymer end groups, repeating structures (linear, cyclic, or branched), and copolymerization. High-energy collision–induced dissociation (HE-CID) is a fragmentation method that is available only in tandem time-of-flight mass spectrometry (TOF–TOF). The informative fragmentation channels, which are difficult to observe with commonly used low-energy CID, are often observable in HE-CID spectra. In MSTips 270, we proposed a method to visualize this abundant structural information and enable intuitive analysis using the “Remainders of KM” (RKM) plot method. In this report, we applied the method to analyze polyethylene oxide (PEO) with different end groups.
We dissolved polypropylene glycol HO (C2H4O)nH, polyethylene glycol monolauryl ether HO (C2H4O)nC12H25, and polyoxyethylene monocetyl ether HO (C2H4O) nC16H33 in methanol (10 mg/mL). We used α-cyano-4-hydroxycinnamic acid (α-CHCA; 10 mg/mL in methanol) and sodium trifluoroacetate (NaTFA; 10 mg/mL in methanol) as matrix and cationizing agent, respectively. The sample, α-CHCA, and NaTFA were mixed at 1:10:1 (v/v/v), spotted on a target plate, and air dried. Product-ion spectra were acquired in positive-ion mode using JMS-S3000 SpiralTOF™ with the TOF–TOF option. We analyzed the data using msRepeatFinder version 3.0.