Characterization of Eraser Wipe Solid Extraction Method Targeting Indoor and Outdoor Surface Films Influenced by Biomass Burning Aerosol

JOSEPH BERBERICH, Janie (Yeaseul) Kim, Holden Schoenherr, Christopher Cappa, Elise Palombella, Shareen Ashby, Victoria Barber, Rachel O'Brien, University of Michigan

     Abstract Number: 242
     Working Group: Indoor Aerosols

Abstract
Wildfires produce immense quantities of biomass-burning aerosol (BBA) particles, which present health challenges for people living downwind, including oxidative stress, inflammation, and respiratory issues. Wildfire smoke may infiltrate, and BBA particles can deposit onto surfaces indoors and influence surface film development. Surface films act as a source and sink for semi-volatile organic compounds, a site for chemical reactions, and a means for resuspension of aerosol particles once perturbed. As humans spend ~90% of their time indoors and indoor environments have much greater surface-area-to-volume ratios than outdoor environments, chemical exposure (transdermally or respiratorily) to surface films can be important to understanding human health in fire-impacted areas. Based on economic and logistical challenges, passive/offline sampling approaches to analyze BBA-influenced surface films are desirable. However, common extraction approaches have limitations; liquid extraction surface analysis (LESA) is often impractical for porous or vertical surfaces, and solid-phase extraction with Kimwipes can have poor extraction efficiencies. Herein, we propose and validate a solid-phase extraction of surface films using poly(melamine-formaldehyde) polymer sponges, commercially available for low cost as the Mr. Clean Magic Eraser® (ME). We probe a matrix of analytes (polar and nonpolar), approaches (commercial sponge, treated sponge, LESA, and Kimwipe), and surfaces commonly found indoors to evaluate our extraction efficiency and application space. We use high-resolution Orbitrap mass spectrometry (MS) and offline high-resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS) to analyze samples for qualitative and quantitative information. We compare our validation experiments to various surfaces sampled with ME wipes at UC Davis campus (outdoors, 2024) and Californian homes near/next to wildfires (outdoors/indoors, 2025). Our analysis will help improve the methodological landscape to extract BBA-influenced surface films for indoor and outdoor surfaces.