Razvoj novih protokola za izolaciju polietilen tereftalata i polistirena iz morskih uzoraka te njihova identifikacija pomoću ATR-FTIR-a i MALDI-MS-a

Polymers are macromolecules with repeated structural units. Synthetic polymers have first been introduced in the middle of the 19th century, and since then their production has exponentially increased on yearly basis. As of 2015, more than 6300 Mt of plastic waste has been generated throughout the world, with more than 76% of that waste ending in landfills and oceans. To fully estimate the effect of this pollution on our planet, simple standardized protocols should be set in place for microplastic analysis. This study presents a novel approach for isolating polyethylene terephthalate (PET) and polystyrene (PS) particles and their quantification and identification using Fourier transformation infrared spectroscopy (FTIR) and matrix-assisted laser desorption ionization (MALDI) mass spectrometry. Additionally, seawater samples were analyzed to determine and optimize the microplastic isolation protocol using chemical digestion of the organic matter coupled with density separation of microplastic from sodium metatungstate (SPT) saline solution. Chemical digestion of the organic matter from seawater samples was tested with both hydrogen chloride (HCl) and hydrogen peroxide (H2O2) solutions. FTIR was later used to determine minimal concentration of PET and PS in seawater needed for their identification. Acquired minimal concentration was further tested with reagents used in chemical digestion to assess the effect of various solutions on PET and PS particles identification. The MALDI method for PET and PS identification was used to study the effect of different polymer suspension concentrations and two different cationization agents, sodium iodide (NaI) and silver trifluoroacetate (AgTFA). Identification of both PS and PET with FTIR in different solutions as well as the development of the MALDI method for PET identification were successful.