A new elemental analytical approach for microplastic sum parameter analysis-ETV/ICP-MS with CO₂

Area of Science:

• Environmental Science
• Analytical Chemistry
• Materials Science

Background:

• Microplastics (MPs) are significant global pollutants, posing challenges for environmental analysis.
• Current analytical methods for MPs in complex matrices are often slow and lack SI traceability.
• A need exists for rapid, comprehensive, and standardized MP detection techniques.

Purpose of the Study:

• To develop a fast screening tool for the sum parameter analysis of microplastics.
• To enable SI-traceable quantification of MPs in environmental samples.
• To overcome limitations of existing MP detection methods.

Main Methods:

• Utilized electrothermal vaporization (ETV) coupled to inductively coupled plasma-mass spectrometry (ICP-MS).
• Developed a size-independent detection method for MPs based on ¹³C⁺ signal.
• Employed external gas calibration with dynamic CO₂/argon dilution for quantification.

Main Results:

• Demonstrated size-independent detection of MPs across nano- to micrometer ranges, irrespective of polymer type.
• Achieved quantification of ¹³C⁺ MP signals with 80-96% recovery rates using MP reference material.
• Successfully applied the method to a soil sample via spiking experiments with polyethylene MP reference material.
• Established a limit of detection (LOD) of 0.13 µg C and a limit of quantification (LOQ) of 0.42 µg C.

Conclusions:

• The developed ETV-ICP-MS method provides a fast and comprehensive analytical approach for microplastic sum parameter analysis.
• This technique offers SI-traceable quantification, addressing a critical gap in current MP analysis.
• The proof-of-concept study highlights the potential for routine application in complex environmental matrices like soil.