Analytical Chemistry Department, GUIA Group, I3A, EINA, University of Zaragoza, Mª de Luna 3, 50018, Zaragoza, Spain.
ASSET Technology Centre, Institute for Global Food Security, School of Biological Sciences, Queens University Belfast, 9, Belfast, Northern Ireland, UK.
Anal Bioanal Chem. 2022 Jan;414(3):1335-1345. doi: 10.1007/s00216-021-03755-0. Epub 2021 Nov 8.
Biopolymers based on polylactic acid (PLA) and starch have numerous advantages, such as coming from renewable sources or being compostable, though they can have deficiencies in mechanical properties, and for this reason, polyester resins are occasionally added to them in order to improve their properties. In this work, migration from a PLA sample and from another starch-based biopolymer to three different food simulants was studied. Attention was focused on the determination of oligomers. The analysis was first performed by ultraperformance liquid chromatography quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS), which allowed the identification of the oligomers present in migration. Then, the samples were analyzed by two ambient desorption/ionization techniques directly coupled to mass spectrometry (ADI), direct analysis in real-time coupled to standardized voltage and pressure (DART-MS) and atmospheric pressure solids analysis probe (ASAP-MS). These methodologies were able to detect simultaneously the main oligomers migrants and their adducts in a very rapid and effective way. Nineteen different polyester oligomers, fourteen linear and five cyclic, composed of different combinations of adipic acid [AA], propylene glycol [PG], dipropylene glycol [DPG], 2,2-dibutyl-1,3-propanediol [DBPG], or isobutanol [i-BuOH] were detected in migration samples from PLA. In migration samples from starch-based biopolymer, fourteen oligomers from poly(butylene adipate co-terephthalate) polyester (PBAT) were identified, twelve cyclic and two linear. The results from ADI techniques showed that they are a very promising alternative tool to assess the safety and legal compliance of food packaging materials.
基于聚乳酸（PLA）和淀粉的生物聚合物具有许多优点，例如它们来自可再生资源或可生物降解，但它们的机械性能可能存在缺陷，因此，偶尔会向它们中添加聚酯树脂以改善其性能。在这项工作中，研究了 PLA 样品和另一种基于淀粉的生物聚合物向三种不同食品模拟物的迁移情况。研究重点是测定低聚物。首先通过超高效液相色谱四极杆飞行时间质谱法（UPLC-Q-TOF-MS）进行分析，该方法允许鉴定迁移中存在的低聚物。然后，通过两种直接与质谱联用的环境解吸/电离技术（ADI），直接实时分析与标准化电压和压力（DART-MS）和常压固体分析探针（ASAP-MS）对样品进行分析。这些方法能够非常快速有效地同时检测主要的低聚物迁移体及其加合物。在 PLA 的迁移样品中检测到了十九种不同的聚酯低聚物，其中十四种为线性，五种为环状，由己二酸[AA]、丙二醇[PG]、二丙二醇[DPG]、2,2-二丁基-1,3-丙二醇[DBPG]或异丁醇[i-BuOH]组成的不同组合。在基于淀粉的生物聚合物的迁移样品中，鉴定出了聚（己二酸丁二醇酯-co-对苯二甲酸酯）聚酯（PBAT）的十四种低聚物，其中十二种为环状，两种为线性。ADI 技术的结果表明，它们是评估食品包装材料安全性和合规性的非常有前途的替代工具。
