Comprehensive Analysis of Microplastics and Their Adsorbed Environmental Matrix Constituents Using a Combination of Thermal Desorption and Pyrolysis with GCxGC-HRTOFMS

Importance of the Topic

Environmental contamination by microplastics and their associated chemicals poses a growing risk to ecosystems and human health. Analytical methods that fully characterize both polymer fragments and adsorbed pollutants are essential for monitoring air quality and understanding pollutant transport.

Study Objectives and Overview

The study aimed to analyze air filter samples collected at rural and urban sites for microplastic particles and co adsorbed compounds. A combined thermal desorption and pyrolysis workflow paired with two dimensional gas chromatography high resolution time of flight mass spectrometry was applied to enable comprehensive profiling of both volatile and high molecular weight targets.

Methodology and Instrumentation

• Sample collection: PM10 quartz filters used for 24 hour sampling.
• Sample preparation: Filter punches transferred into quartz tubes inserted into a multi mode inlet.
• Analysis workflows:
  1. Thermal desorption with electron ionization and GCxGC HRTOFMS for semivolatile organics.
  2. Pyrolysis followed by GCxGC HRTOFMS for polymer identification and pyrolytic marker detection.
• Instrumentation: Pegasus HRT+ 4D system with multi mode source, GL Sciences Optic 4 inlet, two orthogonal GC columns, high resolution TOF detector.

Main Results and Discussion

Non targeted analysis of semivolatile organics revealed aromatic hydrocarbons, heteroaromatics, linear alcohols, aldehydes and siloxanes. Targeted analysis identified plastics related markers such as styrene and alpha methylstyrene dimers and trimers. In pyrolysis mode, characteristic pyrolytic fragments of polyurethane polyamide polystyrene and polyethylene were detected and confirmed by library matching with high similarity scores. Two dimensional contour plots enhanced peak separation, increased signal to noise and enabled rapid identification of low level compounds.

Benefits and Practical Applications

The combination of thermal desorption and pyrolysis in a single instrument accelerates screening of air filters for both adsorbed pollutants and microplastic composition. High resolution and multidimensional separation improve annotation rates and support retrospective analysis using time aligned fractionation.

Future Trends and Applications

Advances in high resolution multidimensional chromatography and data processing will further enhance detection of emerging contaminants. Integration with automated data mining and machine learning can enable routine air quality surveillance and source apportionment studies for microplastic pollution.

Conclusion

The presented TD Py GCxGC HRTOFMS method offers a versatile platform for comprehensive assessment of microplastics and associated environmental chemicals. By capturing both adsorbed organics and polymer markers the workflow improves pollutant screening in complex air samples.

References

No additional references provided in source text