Quantification and identification of microfibers released from textiles during simulated accelerated washing

• Fabrics were subjected to accelerated washing to assess release of microfibers. • Different methodologies were used: mass balances, microscopy, mFTIR, mRaman, py-GC/MS. • Use of software for automated identification may result in misidentifications. • International standards should be applied for direct comparison of results. Microplastics, including plastic microfibers, consist of a wide range of materials of varying composition and morphology, as well as surface chemistry. Given their already demonstrated ubiquity in the environment and the inherent complexity of the different matrices in which these are found, detection and quantification methods are, consequently, quite disparate and gathered data are often not amenable for comparison. As such, methods for the sampling, quantification and characterization of microplastics should be fit-for-purpose, meaning that they should account for the scientific questions being asked within a determined setting and environment. However, within identical matrices and between comparable research questions, methodologies should match, and standardization should be applied. As such, in this work, fibers from different fabrics were subjected to a simulated accelerated washing process to determine the release of microfibers into the resulting water following established and defined international standards. Though there are numerous examples of scientific works delving into this subject, the present work constitutes an initial step towards the use of internationally recognized methodologies for the determination of microfibers during washing processes that, when in conjunction with other similarly carried out works, may contribute to a better understanding of the mechanisms of release of these materials during everyday activities, such as washing and drying of clothes. Furthermore, experimental results showed that special care and attention should be paid when resorting to automated software-based identification of microplastics in environmental matrices, as this may not be as accurate as previously considered, particularly for increasingly used techniques, such as pyrolysis-gas chromatography/mass spectrometry.