基于FT-IR和GC-MS分析市售PLA吸管中挥发性物质

Analysis of Volatiles in Commercially Available Polylactic Acid Straws Using Fourier Transform Infrared Spectroscopy and Gas Chromatography-Mass Spectrometry

通过傅里叶变换红外光谱法对收集的市售聚乳酸(polylactic acid,PLA)吸管样品进行成分鉴定,采用气相色谱-质谱(gas chromatography-mass spectrometry,GC-MS)法对吸管样品进行非靶向分析,结合保留指数、NIST谱库和MS-DIAL解卷积定性,利用物质数据库对化合物进行溯源和安全风险关注。结果表明,样品均为PLA或以PLA为基材,不同程度混合了聚己二酸/对苯二甲酸丁二醇酯和聚丁二酸丁二醇酯;GC-MS分析检测出41种挥发性物质,顶空GC-MS检出173种挥发性物质,主要为塑料添加剂以及可能来源于原材料的杀虫剂、洗涤剂等,部分物质安全性应当被重点关注。GC-MS和顶空GC-MS结果相互补充,有利于更准确地分析挥发性物质。本研究为市售PLA吸管中挥发性物质的分析及安全风险评估提供基础。

Commercially available straw samples were collected for compositional analysis by Fourier transform infrared(FT-IR) spectroscopy,and the non-targeted analysis of volatile compounds in the straw samples was performed by gas chromatography-mass spectrometry(GC-MS).The compounds were identified using retention index,the National Institute of Standards and Technology(NIST) mass spectral library and mass spectrometry-data-independent acquisition(MS-DIAL)deconvolution,and relevant databases were used for traceability analysis and to identify compounds of safety concern.The results showed that the samples were all found to comprise PLA alone or mixed with poly(butyleneadipate-co-terephthalate)(PBAT) and poly(butylene succinate)(PBS) in different proportions.Totally 41 volatile substances were detected by GC-MS,and 173 volatile substances by headspace GC-MS(HS-GC-MS),mainly plastic additives and pesticides and detergents that may originate from raw materials,and the safety of some substances should be of concern.The results of GC-MS and HS-GC-MS were complementary to each other,which is beneficial for more accurate analysis of volatile substances.This study provides a basis for the analysis and safety risk assessment of volatile substances in commercially available PLA straws.