Mozhgan Panji: Evaluating Oxidative Digestion Methods for Reliable Airborne Microplastic Analysis

This study evaluates three oxidative digestion protocols for the pre-treatment of small reference microplastics: 30% H₂O₂ at 70°C for 24 h, 30% H₂O₂ at 55 °C for 48 h, and Fenton oxidation. Eight polymer types were assessed for chemical and morphological stability using ATR-FTIR and SEM, while quantitative method development was performed using pyrolysis–gas chromatography–mass spectrometry (Py-GC/MS).

SEM showed no discernible surface alterations following digestion, whereas FTIR indicated limited chemical changes in PVC and polyurethane. Py-GC/MS method development also demonstrated substantial matrix-related effects on the response of anthracene-d₁₀ used as an internal standard, particularly in the presence of polymer mixtures and quartz filter material. These findings highlight the importance of evaluating both digestion-induced polymer changes and matrix effects when developing reliable quantitative methods for atmospheric microplastic analysis.</p>