Detection of Plasticizers and Flame Retardants in Polymers by Pyrolysis GC-APCI QTOF MS

Significance of the Topic

Analytical detection of plasticizers and flame retardants in polymeric materials is essential for safeguarding human health and meeting evolving regulatory standards. Many additives used to impart flexibility or fire resistance have been linked to toxicological concerns, including endocrine disruption and developmental toxicity. Rapid and reliable screening methods are therefore vital for industries ranging from textiles to protective equipment manufacturing.

Objectives and Overview of the Study

This work aimed to apply pyrolysis gas chromatography coupled with atmospheric pressure chemical ionization quadrupole time-of-flight mass spectrometry (Py‐GC‐APCI‐QTOF MS) to identify 85 target plasticizers and flame retardants directly in various fabric samples. Five fabric types—cotton T-shirt, polyester T-shirt, and three protective gear layers (moisture barrier, thermal barrier, outer lining made of Kevlar®, Nomex®, PBI® blends)—were screened using a targeted suspect-screening workflow.

Methodology and Instrumentation

Sample Preparation and Pyrolysis:

• Pieces of fabric (100–200 µg) were heated to 750 °C in a CDS Model 6200 Pyroprobe, generating volatile fragments.
• Pyrolysates were transferred at 300 °C into a Bruker 456 GC and separated on a Restek RXI-5Sil MS column (30 m ×0.25 mm, 0.25 µm).

Chromatographic Conditions:

• GC temperature program: 40 °C (1 min), ramp 6 °C/min to 320 °C, hold 5 min.
• Injector: split 50 at 280 °C; transfer line and valve oven at 300 °C.

Mass Spectrometry and Data Analysis:

• Bruker compact UHR-QTOF MS with GC-APCI in positive ion mode (m/z 20–1000, 3 Hz).
• Calibration with PFTBA; corona needle at 4000 nA; dry gas 1 L/min at 150 °C.
• TASQ software Suspect Finder used for high-resolution extracted ion chromatograms (±3 mDa) and mSigma scoring.

Main Results and Discussion

Cotton T-shirt:

• Predominant pyrolysis peaks corresponded to cellulose breakdown products.
• Only melamine (a flame retardant) was detected among the 85 targets.

Moisture Barrier Fabric:

• Major peaks reflected Kevlar®/Nomex® decomposition.
• Detected ethyl terephthalate and four additional target analytes at low abundance using TASQ’s traffic-light scoring (green/yellow indicators for match confidence).

Other Fabrics:

• No target additives were found in the polyester T-shirt, thermal barrier, or outer lining under the chosen conditions.

Benefits and Practical Applications

• Direct analysis of solid samples without extensive preparation increases throughput.
• High mass accuracy (<2 ppm) and isotope ratio confirmation (<2 % error) support unambiguous identification.
• TASQ software enables rapid screening, confirmation, and semi-quantitation of a large target list in complex matrices.
• Applicable to quality control of textiles, protective gear certification, and regulatory compliance monitoring.

Future Trends and Potential Uses

• Integration of automated pyrolysis sampling with online data processing for real-time screening.
• Expansion of suspect libraries to emerging additives and non-halogenated flame retardants.
• Coupling with tandem MS/MS acquisition to improve isomer differentiation.
• Application to other polymeric and composite materials in consumer products and environmental samples.

Conclusion

Py-GC-APCI-QTOF MS combined with targeted suspect screening offers a robust platform for detecting hazardous additives in polymers. The method’s minimal sample prep, high specificity, and flexible data mining make it well suited for routine screening in industrial and regulatory laboratories.

Reference

1. Shaw S. et al. Halogenated flame retardants: Do the fire safety benefits justify the risks? Rev. Environ. Health. 2010;25:261–306.
2. National Institute of Environmental Health Sciences. Flame Retardants. Reviewed October 12, 2018.
3. Kind T., Fiehn O. Metabolomic database annotations via query of elemental compositions: Mass accuracy is insufficient even at less than 1 ppm. BMC Bioinformatics. 2006;7:234.