MALDI-TOF MS stability study of model poly(p-phenylene terephthalamide)s

Area of Science:

• Polymer Analysis
• Mass Spectrometry

Background:

• Poly(p-phenylene terephthalamide) (PPD-T) is a high-performance polymer.
• Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a common technique for polymer analysis.

Purpose of the Study:

• To investigate potential chain fragmentation of PPD-T during MALDI-TOF MS analysis.
• To differentiate between fragmentation caused by sample preparation and the MALDI laser.

Main Methods:

• Utilized evaporation-grinding (E-G) MALDI sample preparation method.
• Employed analysis of variance (ANOVA) to statistically assess fragmentation.
• Varied laser area and laser fluence during MALDI-TOF MS analysis.

Main Results:

• No significant PPD-T chain fragmentation was observed due to the E-G MALDI sample preparation method, even with increased grinding.
• Laser fluence showed a significant effect on lower mass oligomers (<1,400 Da) but not on higher mass species (up to ~2,300 Da).

Conclusions:

• MALDI-TOF MS analysis, particularly the E-G preparation method, is unlikely to cause PPD-T chain fragmentation.
• Observed low mass species are likely artifacts from PPD-T synthesis, amplified during sample preparation and analysis.