Overview
ISO/TS 21396:2017 - Rubber - Determination of mass concentration of tire and road wear particles (TRWP) in soil and sediments - Pyrolysis‑GC/MS method specifies a laboratory procedure to quantify the mass concentration (µg/g) of tyre and road wear particles (TRWP) in soil and sediment samples. The technique uses pyrolysis followed by gas chromatography/mass spectrometry (pyrolysis‑GC/MS) to generate and quantify polymer dimer fragments that are specific to tyre rubber polymers. Results can be reported on a TRWP, tyre rubber polymer, or tyre tread basis.
Key topics and technical requirements
- Principle: Thermal decomposition of tyre polymers produces characteristic dimeric pyrolysis fragments (NR, SBR, BR dimers) that are separated by GC and identified by MS. Dimer markers provide greater specificity than monomer markers, which can be interfered with by non‑TRWP sources (e.g., styrene from diesel).
- Sample collection & preparation:
- Field sampling using pre‑cleaned trowels, corers or dredges.
- Oven drying at 105 °C for 24 h is specified for dry mass determination.
- Dry sieving/homogenization (nominal sieve opening ~1 mm) to prepare material for pyrolysis.
- Precision balance requirements (accuracy to 0.01 mg) for mass measurements.
- Analytical method:
- Addition of a deuterated internal standard to correct for matrix effects, instrument drift and recovery.
- Preparation of calibration curves from stock solutions and internal standards.
- Pyrolyser operation at 670 °C for 5 s in a helium atmosphere; high‑purity helium specified for carrier gas.
- Quantification & reporting:
- Calculation of polymer mass in the sample from dimer peak areas and internal standard calibration.
- Conversion of polymer mass to TRWP concentration (µg/g), accounting for tyre tread and mineral encrustation fractions.
- Performance: The specification addresses measuring range, method detection limits, repeatability, and test report requirements.
Applications
- Environmental monitoring of TRWP in urban soils, roadside sediments, and aquatic sediments.
- Comparative and trend studies to assess temporal changes in TRWP loads.
- Supporting environmental impact assessments, source apportionment, and mitigation studies for microplastic and tyre wear pollution.
- Research into tyre composition, road abrasion, and fate/transport of TRWP.
Who should use this standard
- Environmental testing laboratories and analytical service providers.
- Academic and government researchers studying microplastics, particulate pollution, or soil/sediment contamination.
- Regulatory agencies, road authorities and consultants performing baseline or monitoring studies.
- Tire manufacturers and material scientists investigating abrasion and wear.
Related standards
- ISO 7270‑1 - Rubber - Analysis by pyrolytic GC methods - Part 1: Identification of polymers (referenced normatively for pyrolysis‑GC identification procedures).
Keywords: ISO/TS 21396:2017, TRWP, tyre and road wear particles, pyrolysis‑GC/MS, soil, sediments, tyre rubber polymer, dimer markers, deuterated internal standard, environmental monitoring.