## 3 Results and Discussion  
### Identification of Volatile and Semi-Volatile Compounds by GC-MS  
The optimization of PBAT and TPS/PBAT sample extraction was achieved through solvent extraction using ethanol and dichloromethane. This method was chosen because it detects a greater number of highly volatile compounds with a lower expansion volume [17; 18; 19; 20]. Compound identification was analyzed via GC-MS using liquid injection. Figure 1 shows a chromatogram of the dissolved PBAT and TPS/PBAT films obtained through solvent extraction, facilitating the identification of unknown migrants in food contact materials. Table 2 lists 13 identified compounds with library matching scores \(\geq\) 80% compared to NIST library. A total of 15 different volatile compounds were reported in the literature, with 7 found in PBAT resin and 9 in PBAT film. Both PBAT resin and film samples exhibited identical compounds when analyzed by GC-MS. Cyclopentancarboxylic acid, 2-oxo-, ethyl ester is a degradation by-product of PBAT resins, as reported by [PERSON] et al. [21] and [PERSON] et al. [7]. Additionally, 1,6-Dioaxacyclododecane-7,12-dione is a cyclic molecule formed during PBAT polymerization via polyester condensation involving the monomers 1,4-butanediol and adipic acid. It was found in both the resin and film and is classified as a non-intentionally added substance (NIAS) as noted by [PERSON] et al. [7], [PERSON] et al. [22], [PERSON] et al. [23]. Other compounds present at lower intensities in both PBAT resin and film included cyclopentanone, tetraethyl silicate, butylated hydroxytoluene (BHT), 2-ethylhexyl salicate, methyl stearate, and ethyl stearate [19; 24]. Cyclopentanone is formed by a radical reaction between aldehydes and ketones occurring in PBAT resin. The intensity of this peak slightly decreased in film samples, likely due to the high temperature during film manufacturing, as previously detected by [PERSON] et al. [23] and [PERSON] et al. [21]. Tetraethyl silicate, a silane compound, is a common additive used as a coupling agents in resins, adhesives, and inks to improve their chemical and thermal resistance [25]. BHT, used as an antioxidant or plastic stabilizer, is approved for food contact applications under EU regulation [26] and was previously detected by [PERSON] et al. [6] and [PERSON] et al. [27]. However, BHT has been scrutinized for its potential endocrine-disrupting properties and long-term safety at higher exposure levels [28]. 2-Ethylhexyl salicate, used as a UV-filter additive, is generally regarded as safe but may contribute to cumulative exposure risks depending on its concentration and frequency of ingestion [29]. Stearate compounds were detected and are derived from fatty acids from, though they are also commonly found as contaminants in packaging materials. Additionally, an unknown compound with a retention time of 26.00 min was also detected. Based on the bibliographic information and mass spectrum several key fragments were observed: \(m/z\) 54.0 likely represents a small alkyl chain breakage associated with the molecule's fragmentation, while \(m/z\) 104.0 could correspond to a larger fragment, indicating more complex molecular breakage possibly involving part of the cyclic structure. The mid-range \(m/z\) values of 132.0 and 149.0 may represent fragments of the dioxacyclododecane core, reflecting partial structures of the compound. Finally, \(m/z\) 369.1 represents the molecular ion peak (M+), which corresponds to the entire molecule and is characteristic of the molecular mass of 1,6-Dioxacyclododecane-7,12-dione. Given this fragmentation pattern, the compound is likely an oligomer formed during the PBAT polymerization process via polyester condensation, which involves the monomers 1,4-butanediol and adipic acid. This suggests that the compound is a larger oligomer than 1,6-Dioxacyclododecane-7,12-dione, which also has a similar fragmentation pattern.