Understanding the Need for Mass Balance Measurements in Microplastics and the Three GC/MS Techniques Used to Get Them

Analyzing Microplastics in the Environment: Striving to Better Assess Occurrence, Fate and Effects
Oral Presentation

Prepared by K. Thaxton
GERSTEL Inc., 701 Digital Drive Suite J, Linthicum Heights, Maryland, 21090, United States

Contact Information: kurt_thaxton@gerstel.com; 14102475885


Measuring microplastic (MP) contamination in drinking water, surface waters, waste water, and other sources has been an focus in the European Union for many years now, and in the last few years has become a growing interest in North America, with a particular focus in coastal water systems in the US west coast. Measurement of MP’s in indoor air similar matrices has also been a growing interest in the standards community and the scientific community as a whole.

MP’s cannot be measured using a single technique; many different types of information are desired (particle size, polymer content, mass balance, and metal content). Spectroscopic techniques such as IR and Raman microscopy are commonly used for particle size and polymer identification; ICP emission spectroscopy or mass spectrometry are used for metal content.

Mass balance information is also needed and is determined differently. Mass balance is the relative composition of the major polymers that make up a collection of MP particles in aggregate. It is the next step beyond polymer identification: the relative amounts of the polymers present.

Both polymer identification and mass balance can be determined by thermal extraction, pyrolysis, or thermal extraction-desorption GC/MS. This talk will provide an overview of each of these three approaches with a explanation of each technique, including sampling and preparation, and of the strengths and weaknesses of each when used for mass balance determinations.