# Simply Applicable Method for Microplastics Determination in Environmental Samples
## 1 Introduction
The main degradation products of PET, found in the thermal degradation studies, were carbon dioxide, acetaldehyde, vinyl benzoate, terephthalatic acid, benzaldehyde, divinyl terephthalate, benzoic acid, linear dimers, and cyclic oligomers of up to three monomer units in size [15]. PS is an aromatic polymer, produced by the polymerization of styrene monomer units and is used to produce packaging materials and insulation [16]. Dominated PS thermal decomposition mechanisms are thought to be random and chain-end scissions, followed by depolymerization, intramolecular transfer and bimolecular termination, which lead to the formation of styrene and its larger units (dimers, trimers), aromatics, light hydrocarbons, and some oligomeric fragments [8; 14; 17; 18]. The main degradation products of TED-GC-MS and Py-GC-MS analyses were identified as styrene, 2,4-diphenyl-1-buten (dimer), and 5-hexene-1,3,5-triyltribenzene, 2,4,6-triphenyl-1-hexene (trimers) [7; 8; 13; 18; 19; 20]. PVC is the most common halogenated polymer, made with the polymerization of vinyl chloride, and currently it is mainly used in the production of construction materials and household accessories [14; 16]. Thermal degradation of PVC is reportedly a complex process, generally taking place in two stages [21]. The first stage is the dehydrochlorination process (200-277 \({}^{\circ}\)C), where hydrogen chloride (HCI) is eliminated via random scission of secondary chlorine atoms and leaving the unsaturated hydrocarbons behind [14; 22]. The second stage (above 300 \({}^{\circ}\)C) comprises of the degradation of the double bond hydrocarbon backbone, and following the hydrogen evolvement, further splitting up the unsaturated hydrocarbons into small unsaturated linkages, resulting in the occurrence of volatile saturated and unsaturated, aliphatic and aromatic hydrocarbons, such as benzene and toluene [23; 24; 25; 22]. Py-GC-MS for MPs identification mainly detected aromatic hydrocarbons, such as biphenyl, toluene, naphthalene, fluorine, benzene [10; 18; 20], while chlorobenzene was only detected with the TED-GC-MS method [19]. The lack of detected chlorinated compounds with these methods could be, according to [PERSON] et al. [10], a consequence of enhanced elimination of the main dehydrochlorination compound, HCl. Chlorinated hydrocarbons, namely 1-chlorododecane and dichlorobenzene, were detected after thermal decomposition of waste plastic pellets at 200 \({}^{\circ}\)C in the air and 1-chlorobutane was detected as a VOC from PVC based wrapping films [26; 27]. PP and PE are the most commercially produced and used aliphatic polymers. They are obtained using the polymerization of ethylene and propylene, respectively, and their thermal decomposition has been well researched. Hydrocarbons with several structural types and isomers are the main thermal decomposition products of polyolefins, such as PP and PE and this is the main reason why their identification poses a challenge [28]. PP reportedly degrades by random backbone chain scission into a repeating pattern of mainly methylated alkenes and unsaturated hydrocarbons [10; 29]. Out of these, the most common and abundant is reported to be a trimer, 2,4-dimethylhept-1-en, as the main product of PP splitting [28; 30]. This trimer was also identified in Py-GC-MS and TED-GC-MS analyses of PP, and commonly identified thermal degradation products 2,4,6-trimethyl-1-nonene, 2,4,6,8-tetramethyl-1-undecene, and 2,4,6-trimethyl-1-nonene [7; 13; 18; 19; 20]. Despite PE and PP both being polyolefins, the thermal decomposition of PE gives different distribution of components than the decomposition of PP [29; 30]. The main mechanism of PE thermal decomposition has been reported to be random chain scission into saturated, monounsaturated, and diunsaturated hydrocarbons [28]. These are, according to [PERSON] et al. [31], unique in their formation of distinct patterns of series of triplets of the aliphatic carbons (alka-\(\alpha\),\(\omega\)-diene, alike-1-en, and n-alkane).