Fast Screening of Polycyclic Aromatic Hydrocarbons using Trapped Ion Mobility Spectrometry - Mass Spectrometry

Area of Science:

• Analytical Chemistry
• Environmental Science
• Physical Chemistry

Background:

• Polycyclic aromatic hydrocarbons (PAH) are prevalent environmental contaminants.
• Accurate identification of PAHs in complex matrices is challenging.
• Conventional separation techniques for PAHs can be time-consuming.

Purpose of the Study:

• To demonstrate the advantages of trapped ion mobility spectrometry coupled to mass spectrometry (TIMS-MS) for rapid PAH identification.
• To report accurate collision cross-section (CCS) values for common PAHs.
• To showcase the separation of PAH geometric isomers and application to complex mixtures.

Main Methods:

• Utilized trapped ion mobility spectrometry coupled to mass spectrometry (TIMS-MS).
• Performed theoretical calculations using DFT/B3LYP for structure optimization.
• Measured experimental collision cross-section (CCS) values in nitrogen as a bath gas.
• Analyzed a complex soil mixture sample.

Main Results:

• Achieved millisecond timescale identification of PAHs.
• Reported accurate experimental CCS values for common PAHs with <5% agreement with theoretical calculations.
• Demonstrated separation of three isobaric PAH pairs with mobility resolution >150.
• Successfully applied TIMS-MS to a complex soil mixture without extensive pre-separation.

Conclusions:

• TIMS-MS combined with theoretical calculations provides a powerful tool for rapid and accurate PAH identification.
• The high mobility resolution of TIMS-MS enables separation of PAH isomers.
• This approach simplifies the analysis of PAHs in complex environmental samples.