聚乳酸(PLA)秸秆具有环保潜力;然而,用于增强机械强度的残留二异氰酸酯会产生致癌的伯芳胺(PAAs),构成健康风险。在这里,我们提出了一个快速的,在18个品牌的食品级PLA吸管中检测PAA并评估其迁移到各种食品模拟物中的综合策略。进行表面增强拉曼光谱以快速筛选秸秆中的PAAs。随后,定性测定将PAAs迁移到各种食品模拟物中(4%乙酸,10%乙醇,50%乙醇)在70°C下使用液相色谱-质谱法进行2小时。三种PAA,包括4,4'-亚甲基二苯胺,2,4'-亚甲基二苯胺,在所有秸秆中均检测到2,4-二氨基甲苯。具体来说,50%乙醇中的2,4-二氨基甲苯超过2μg/kg的特定迁移极限,引发安全担忧。值得注意的是,在短短2小时内,PAAs向10%和50%乙醇的迁移超过了4%乙酸。此外,PLA秸秆在迁移前后发生了不同程度的形状变化。与没有聚(丁二酸丁二醇酯)的秸秆相比,具有抗变形性,表明增强的耐热性,而聚(己二酸丁二醇酯-共对苯二甲酸酯)改善了耐水解性。重要的是,溶胀研究表明,溶胀作用不是导致乙醇食品模拟物中PAAs迁移增加的主要因素,因为不同食物模拟物的肿胀程度没有显着差异。FT-IR和DSC分析显示,50%乙醇中较高的PAA含量是由于高浓度的极性乙醇破坏了氢键和将PLA分子保持在一起的范德华力。总的来说,减少聚乳酸吸管和酒精食品之间的接触对于避免PAA带来的潜在安全风险至关重要。
Polylactic acid (PLA) straws hold eco-friendly potential; however, residual diisocyanates used to enhance the mechanical strength can generate carcinogenic primary aromatic amines (PAAs), posing health risks. Herein, we present a rapid, comprehensive strategy to detecting PAAs in 18 brands of food-grade PLA straws and assessing their migration into diverse food simulants. Surface-enhanced Raman spectroscopy was conducted to rapidly screen straws for PAAs. Subsequently, qualitative determination of migrating PAAs into various food simulants (4 % acetic acid, 10 % ethanol, 50 % ethanol) occurred at 70 °C for 2 h using liquid chromatography-mass spectrometry. Three PAAs including 4,4\'-methylenedianiline, 2,4\'-methylenedianiline, and 2,4-diaminotoluene were detected in all straws. Specifically, 2,4-diaminotoluene in 50 % ethanol exceeded specific migration limit of 2 μg/kg, raising safety concerns. Notably, PAAs migration to 10 % and 50 % ethanol surpassed that to 4 % acetic acid within a short 2-hour period. Moreover, PLA straws underwent varying degrees of shape changes before and after migration. Straws with poly(butylene succinate) resisted deformation compared to those without, indicating enhanced heat resistance, while poly(butyleneadipate-co-terephthalate) improved hydrolysis resistance. Importantly, swelling study unveiled swelling effect wasn\'t the primary factor contributing to the increased PAAs migration in ethanol food simulant, as there was no significant disparity in swelling degrees across different food simulants. FT-IR and DSC analysis revealed higher PAAs content in 50 % ethanol were due to highly concentrated polar ethanol disrupting hydrogen bonds and van der Waal forces holding PLA molecules together. Overall, minimizing contact between PLA straws and alcoholic foods is crucial to avoid potential safety risks posed by PAAs.