Analysis of advanced materials by FD/FI using “AccuTOF GC” - analysis of multifunctional thiols, curing agents for functional polymers

Significance of the topic

Multifunctional thiols serve as critical curing agents in functional polymer manufacture. Conventional electron ionization often results in extensive fragmentation that obscures molecular ions, challenging accurate mass determination. Field ionization (FI) offers a softer alternative that preserves molecular ions, facilitating reliable characterization of complex thiol compounds.

Objectives and study overview

This study compares gas chromatography–electron ionization (GC/EI) with gas chromatography–field ionization (GC/FI) using the AccuTOF GC mass spectrometer to analyze two multifunctional thiols, Karenz MT® BD1 and PE1, evaluating the ability of FI to detect molecular ions relative to EI fragmentation patterns.

Methodology

• Samples: Karenz MT® BD1 (C12H22O4S2) and Karenz MT® PE1 (C21H36O8S4), multifunctional thiols.
• GC conditions: ZB-5ms capillary column (30 m × 0.25 mm, 0.25 μm); helium at 1.0 mL/min; oven program 40 °C (2 min) → 30 °C/min → 280 °C (12 min).
• MS conditions: EI (70 eV, 300 μA) and FI (cathode −10 kV, emitter 0 mA); mass range m/z 35–550; spectral scan interval 0.4 s.

Used instrumentation

• AccuTOF GC mass spectrometer (JEOL JMS-T100GC).
• ZB-5ms GC column (30 m × 0.25 mm, 0.25 μm film).
• Helium carrier gas delivery and temperature‐controlled GC oven.

Main results and discussion

• GC/EI spectra for BD1 and PE1 exhibited extensive fragmentation without observable molecular ions.
• GC/FI spectra displayed clear molecular ions with minimal fragmentation, enabling precise mass identification.
• FI proved superior for intact molecular ion detection in multifunctional thiols compared to EI.

Practical benefits and applications

• Enhanced molecular ion detection simplifies structural elucidation of curing agents.
• Improved mass accuracy supports quality control in polymer manufacturing.
• FI methodology can extend to other high‐mass, thermally stable compounds.

Future trends and potential applications

• Combining FI with high‐resolution time‐of‐flight analyzers to improve mass accuracy.
• Automated FI ion sources for routine industrial QC workflows.
• Applying FI to complex mixtures such as polymer additives and oligomers.

Conclusion

Field ionization on the AccuTOF GC platform enables robust detection of molecular ions in multifunctional thiols where EI fails, enhancing analytical capabilities for polymer curing agents and promising wider adoption in material science and QA/QC practices.

References

• JEOL Ltd. MS Data Sheet No. 040 and No. 090, Mass Spectrometry Application Group, Mass Spectrometry Business Unit.