Supplementary information files for "Tailored analytical approaches to assess microplastic fibers and nanoparticles release from textiles during washing"

Optical microscopy and scanning electron microscopy were applied for MPF quantification and morphological assessment, while dynamic light scattering and nanoparticle tracking analysis (NTA) provided complementary information on the size distributions and number concentrations of NSPs in the sub-micron fraction. Atomic force microscopy provided high-resolution imaging of individual NSPs, yielding detailed information on particle shape and surface morphology.

Polymer-specific mass release from the MPF fraction was quantified using pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS), supported by total organic carbon analysis, while Fourier transform infrared spectroscopy was used to assess changes in the chemical composition of textiles after washing. In parallel, inductively coupled plasma mass spectrometry was used to assess the release of inorganic elements and trace metals associated with textile materials.

Using the tiered analytical approach, released MPFs ranged from 455 to 843 µm in length with the average diameter from 11 to 23 µm. NSPs released during washing tests ranged from 25 to 100 nm. PLA textiles released more MPFs (2.28 × 10⁵ particles/kg) than Standard PET (1.40 × 10⁵ particles/kg) and Recycled PET (1.32 × 10⁵ particles/kg).

NTA indicated that PLA also released the highest concentration of NSPs (1.97 × 10¹⁰ particles/mL), followed by Recycled PET (1.37 × 10¹⁰ particles/mL) and Standard PET (8.77 × 10⁹ particles/mL). Py-GC/MS revealed higher polymer mass release from PLA (0.36 ± 0.07 mg/L) compared with Standard PET (0.25 ± 0.03 mg/L) and Recycled PET (0.21 ± 0.03 mg/L). In addition, measurable leaching of ⁵⁶Fe (19.14 µg/L) and ¹²¹Sb (28.26 µg/L) of washing water was detected.

Overall, this study highlights how the strategic combination of complementary analytical techniques enables a holistic assessment of textile-derived MPFs, NSPs, and metals emissions during textile washing and reveals differences between conventional synthetic and biobased textiles with tailored analytical approaches, providing new insights for environmental risk assessment.<br><br>© The Author(s), CC BY-NC-ND-4.0</p>