School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom.
School of Metallurgy and Materials, University of Birmingham, Birmingham B15 2TT, United Kingdom.
Environ Sci Technol. 2021 Jul 6;55(13):8721-8729. doi: 10.1021/acs.est.1c01085. Epub 2021 Jun 10.
Reliable chemical identification of specific polymers in environmental samples represents a major challenge in plastic research, especially with the wide range of commercial polymers available, along with variable additive mixtures. Thermogravimetric analysis-Fourier transform infrared-gas chromatography-mass spectrometry (TGA-FTIR-GC-MS) offers a unique characterization platform that provides both physical and chemical properties of the analyzed polymers. This study presents a library of 11 polymers generated using virgin plastics and post-consumer products. TGA inflection points and mass of remaining residues following pyrolysis, in some cases, proved to be indicative of the polymer type. FTIR analysis of the evolved gas was able to differentiate between all but polypropylene (PP) and polyethylene (PE). Finally, GC-MS was able to differentiate between the unique chemical fingerprints of all but one polymer in the library. This library was then used to characterize real environmental samples of mesoplastics collected from beaches in the U.K. and South Africa. Unambiguous identification of the polymer types was achieved, with PE being the most frequently detected polymer and with South African samples indicating variations that potentially resulted from aging and weathering.
可靠地识别环境样品中的特定聚合物是塑料研究中的一个主要挑战，特别是在商业聚合物种类繁多且添加剂混合物变化多样的情况下。热重分析-傅里叶变换红外-气相色谱-质谱联用（TGA-FTIR-GC-MS）提供了一个独特的特征化平台，可提供分析聚合物的物理和化学性质。本研究建立了一个由 11 种聚合物组成的文库，这些聚合物使用原始塑料和消费后产品制成。在某些情况下，热重分析的拐点和热解后剩余残留物的质量证明了聚合物的类型。对释放气体的傅里叶变换红外分析能够区分除聚丙烯（PP）和聚乙烯（PE）之外的所有聚合物。最后，气相色谱-质谱联用能够区分文库中除一种聚合物之外的所有聚合物的独特化学特征。然后，该文库用于表征从英国和南非海滩收集的中密度塑料的真实环境样品。实现了对聚合物类型的明确识别，PE 是最常检测到的聚合物，南非样本显示出的变化可能是由于老化和风化造成的。
