Integrated GC–MS and ATR–FTIR analysis of airborne microplastics captured by spider webs

Our study evaluated airborne microplastics (MPs) captured by spider webs (Agelenidae) in an urban environment (Wrocław, Poland). GC–MS was used to characterize extractable organic compounds linked to MPs, while ATR–FTIR spectroscopy enabled detection of polymer-related signals in solid residues after solvent extraction. All samples contained compounds associated with polymeric materials, including rubber- and silicone-related components, with rubber signals detected at all sites. No significant differences were observed between central and suburban locations, indicating a relatively uniform distribution of airborne MPs. ATR–FTIR results further suggested the occurrence of tire-derived materials in all samples, along with polyamides (Nylon 6; 40%), polypropylene-related materials (including Epcar 5875; ~20%), polyvinyl alcohol (20%), and polyethylene (LDPE; 13%), expressed as frequency of occurrence across samples. Overall, the results demonstrate that spider webs can serve as accessible passive samplers, providing a qualitative and integrative representation of airborne microplastic contamination in urban environments.