Detection, Quantification, and Isomer Differentiation of Per- and Polyfluoroalkyl Substances (PFAS) Using MALDI-TOF...

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Mass Spectrometry

Background:

• Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants with known adverse health effects.
• Accurate analytical methodologies are crucial for characterizing PFAS in diverse sample matrices.
• Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) offers a chromatography-free approach for in situ sample analysis.

Purpose of the Study:

• To develop and optimize a novel analytical method for sensitive and quantitative PFAS detection.
• To enhance PFAS characterization by integrating trapped ion mobility spectrometry (TIMS) with MALDI-MS.
• To demonstrate the capability of the developed method for isomer separation and high-throughput analysis.

Main Methods:

• Utilized matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) coupled with trapped ion mobility spectrometry (TIMS).
• Optimized MALDI matrix composition and instrument parameters for calibration curve generation.
• Employed ion mobility spectrum filtering for enhanced sensitivity and separation.

Main Results:

• Achieved parts per billion (ppb) calibration curves for various perfluorosulfonic acids (PFSAs) and perfluorocarboxylic acids (PFCAs).
• Demonstrated parts per trillion (ppt) calibration curves for PFSAs using ion mobility filtering.
• Successfully separated three structural isomers of perfluorooctanesulfonic acid (PFOS) in the gas phase via TIMS.

Conclusions:

• The developed MALDI-TOF-MS/TIMS method provides a fast, quantitative, and sensitive approach for PFAS analysis.
• This technique facilitates high-throughput and in situ analysis of PFAS, including potential for MS imaging.
• The ability to separate isomers offers deeper insights into PFAS contamination and toxicology.