This project will develop and implement microplastic extraction and characterization from an environmental Standard Reference Material (SRM) 2585 Organic Contaminants in House Dust, and a subsequent effort to analyze the extracted microplastics for per- and polyfluoroalkyl substances (PFAS). This effort will develop analytical and characterization methods for quantifying microplastics that could be used to assist laboratories in their own efforts. SRM 2585 has known, homogenous PFAS concentrations, but it is unclear if the microplastic fraction contributes to the overall PFAS concentration of the material. SRM 2585 is anticipated to be one of the most difficult matrices to separate microplastics from due to the high content of organic material. By developing methods for a more complex and analytically difficult matrix, future method development for other environmental matrices such as sediment or soil should be more straightforward. A detailed evaluation of both microplastics and PFAS concentrations in the microplastic and non-microplastic fractions from a complex matrix will help underpin future efforts in the field and improve quality laboratory performance.

The National Institute of Standards and Technology SRM 2585 Organic Contaminants in House Dust has reference mass fractions for select PFAS, but microplastics quantities and types have not been investigated. Plastics and PFAS are known to be associated, but the interaction between these two chemicals of concern in SRM 2585 are currently unknown. This project is divided into three primary tasks. Task one focuses on separating the microplastics from the rest of the abiotic matrix and identifying and quantifying them through the use of attenuated total reflection-fourier transform infrared spectroscopy and pyrolysis-gas chromatography/mass spectrometry (MS). Task two involves the chemical assessment of both the microplastics and remaining dust matrix after separation for 44 individual PFAS via liquid chromatography-MS to include both legacy PFAS (e.g., perfluorocarboxylic acids and perfluorosulfonic acids) and less commonly measured PFAS (e.g., zwitterionic PFAS [e.g.,fluorotelomer betains], perfluoro sulfonamido ethanols, etc). Task three will apply the methods developed to a candidate RM 8697 PFAS in Soil I.

This project will help develop an extraction method to separate microplastics from abiotic matrices, understand the distribution of PFAS within the reference material, and determine whether individual or multiple PFAS are associated with the microplastic fraction. This study will evaluate an available, homogenous product, SRM 2585, for microplastics, and determine if the Certificate of Analysis can be updated to include reference values for microplastics. Currently, no values for microplastics exist in SRM. There is a critical need for an environmental standard containing microplastics and this study will determine if SRM 2585 can fill this necessary role. Additionally, application of this robust microplastic method developed for House Dust to candidate RM 8697 PFAS in Soil I will provide a realistic environmental sample from a PFAS-, but unknown microplastic, impacted location. The successful execution of this research will yield data essential for the development of advanced technologies aimed at enhancing ongoing remediation efforts at PFAS-impacted sites, thereby providing crucial safeguards for warfighters and installation communities. (Anticipated Project Completion - 2026)