Characterization of VOCs and additives in Italian PET bottles and studies on potential functional aldehydes scavengers

This study focused on characterization of Volatile Organic Compounds (VOCs) as contaminants and non-volatile additives in Italian PET bottles, also suggesting potential functional aldehydes scavengers. Several VOCs, such as acetic aldehyde (AA), butanal, 3-methyl butanal, 1,3-dioxolane, pentanal, hexanal, octanal, 5-hepten-2-one, nonanal, and decanal, were identified by Head Space-Gas Chromatography/Mass Spectrometry (HS-GC/MS) in the PET bottles used for the packaging of six Italian brands mineral waters. AA, 1,3-dioxolane, octanal, 5-hepten-2-one, nonanal, and decanal were the most abundant compounds identified. These contaminants were also identified in the PET-bottled mineral waters. Different experiments using bottle-grade PET pellets (Btlg-PET) and PET bottles' fragments with and without the addition of epoxidized soybean oil (ESBO) or erucamide as lubricant/plasticizer additives, poly(m-xylene adipamide) (MXD6), and/or anthranilamide (2-aminobenzamide) as potential aldehydes scavengers were carried out. Mostly VOCs observed in the PET bottles analysed were identified in a neat ESBO sample. The presence of the ESBO additive in the PET-bottle fragments was also observed by matrix-assisted laser desorption/ionization time of flight mass spectrometry analysis (MALDI-TOF MS). The ESBO sub-products were not observed in the virgin btlg-PET pellets analysed by both HS-GC/MS and MALDI-TOF MS. These results suggest that the VOCs come from an ESBO additive probably loaded during the blow-moulding processes used for the manufacturing of PET bottles. Further studies established that MXD6 (1%w), an efficient oxygen scavenger, could be also used as AA scavenger even in the presence of the commonly used anthranilamide.