44 Environmental Geoscience (Posters)

Wednesday, 11 March 2026
9:00 AM - 12:00 PM
RCC, Lower Level Hall

Evaluating Micro-X-ray Fluorescence (μXRF) as a Complementary Tool for Microplastic Particle Identification

Paper number: 44-9
Program: Technical Sessions
Time: 9:00 AM – 9:00 AM

Authors

Abstract

Microplastics are ubiquitous environmental contaminants detected across diverse matrices and represent a growing global concern. Following sample processing steps such as digestion and density separation, particle identification commonly relies on optical microscopy coupled with spectroscopic techniques (e.g., Raman or FTIR). While micro-X-ray fluorescence (μXRF) has previously been applied to characterize hazardous elements in plastics, investigate vessel-induced contamination, and assess metal accumulation on plastic debris, its potential utility for identifying microplastic particles in processed samples remains understudied. Laboratory tests were conducted to evaluate the capabilities of μXRF for particle detection and characterization using the IXRF Systems ATLAS X μXRF spectrometer. In-house created microplastic particles of varying morphologies (fibers, foam, film, and fragments) and sizes, were deposited onto 1.6 μm glass fiber filters. Additionally, organic matter, including cotton fibers, wood, and hair, were analyzed as a control to assess discrimination potential. Elemental mapping was performed at 5-10 μm pixel resolution and a dwell time of 50 ms to evaluate detection limits and spatial resolution. Elemental mapping of trace constituents identified higher concentrations of Ti, Ca, Fe, and Cl in many microplastic particles, consistent with some common pigments, fillers, and additives. The absence of silicon within plastic particles relative to the underlying glass fiber filter enabled effective visualization and discrimination of most microplastics, despite μXRF’s inability to directly identify polymer composition. Non-plastic control samples indicated a mix of elements with a higher presence of Ca, S, Cl, and an absence of Si. An additional test using a stainless-steel filter demonstrated successful detection of a microplastic fiber based on a localized Ti signal and suppression of background Fe. Preliminary results indicate that μXRF analysis could partially support particle counting and spatial characterization following sample processing and removal of non-plastic particles, particularly when pigments, coatings, or additives are present. Limitations include potential long scan times, reduced detection efficiency for particles smaller than 10 μm, and similar elemental signatures that could lead to misclassification. Despite these constraints, results indicate that μXRF analysis shows promise as a complementary tool for microplastic research, particularly for assessing elemental associations, additives, and sorbed contaminants on plastic particles.

Geological Society of America Abstracts with Programs. Vol. 58, No. 1

doi: 10.1130/abs/2026SE-411639

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