Rooftop farming in urban areas showed a growing diffusion in recent years, together with the development of suitable cultivation substrates (technosols), such as those employing urban waste (Fabbri et al., 2021; Grard et al., 2020). However, urban wastes employed as growing substrates could release pollutants, with potential food safety risks. Research in this field focused on pathogens, trace elements, pesticides, and persistent organic pollutants (Buscaroli et, al, 2021), but few studies evaluate micro-and nano-plastics (MP and NP), which are ubiquitous and emerging contaminants. One of the main problems with MP and NP is that analytical quantification is still a challenge, especially within complex organic mixtures such as plant parts or technosols. This study presents a method for the simultaneous identification of synthetic organic matter (SyOM) in a natural organic matter (NOM) matrix employing analytical pyrolysis coupled to GC-MS (Py-GC-MS). This technique volatilizes samples at high temperatures (600°C), and the resulting gases (pyrolyzates) undergo a chromatographic separation followed by mass spectroscopy identification. However, in the case of complex mixtures, the identification is not unambiguous, because of similar produced molecular fragments from SyOM and NOM.