Preliminary study to characterize plastic polymers using elemental analyser/isotope ratio mass spectrometry (EA/IRMS)

Area of Science:

• Environmental Science
• Analytical Chemistry
• Materials Science

Background:

• Plastic waste poses a significant and persistent threat to marine ecosystems globally.
• Monitoring plastic pollution is a key concern, addressed by international conventions and EU directives.
• Plant-derived biodegradable plastics are gaining importance, necessitating new characterization methods.

Purpose of the Study:

• To conduct the first preliminary characterization of carbon stable isotopes (δ¹³C) in various plastic polymers.
• To expand the dataset of isotopic values for applications in polymer research and marine environmental surveillance.
• To investigate the potential of δ¹³C analysis for identifying plastic origins and degradation states.

Main Methods:

• Isotope Ratio Mass Spectrometry (IRMS) was employed for precise δ¹³C measurements.
• Analysis included petroleum-derived, plant-derived (
• BIO
• ) plastics, and recycled materials.
• Collected plastic samples from marine environments were analyzed to assess degradation effects.

Main Results:

• δ¹³C values successfully differentiated plant-derived plastics from petroleum-based ones.
• Recycled plastics showed intermediate δ¹³C signatures.
• Degraded plastics from marine environments exhibited less negative δ¹³C values compared to pristine samples.
• Plastic color did not significantly influence δ¹³C variability.

Conclusions:

• Carbon stable isotope analysis is a valuable tool for tracing plastic origins and assessing degradation.
• IRMS offers sensitive, rapid, and cost-effective analysis for plastic characterization, even for dark samples.
• This method supports enhanced monitoring of plastic pollution in marine ecosystems.