An Untargeted Thermogravimetric Analysis-Fourier Transform Infrared-Gas Chromatography-Mass Spectrometry Approach for Plastic Polymer Identification

Abstract

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.

Adsorption of Tannic Acid and Macromolecular Humic/Fulvic Acid onto Polystyrene Microplastics: A Comparison Study

“…Further, the fingerprint region of an infrared spectrum ranges from 1300 cm −1 -400 cm −1 [29]. Overall, the FTIR spectrum of the PS MPs used in this study are similar to those reported in recent research, despite plasticizers or other additives that may cause the remaining peaks in PS MPs [46]. After HA was adsorbed by PS MPs, new peaks appeared at 3469 cm −1 and 1615 cm −1 , which may be due to the presence of hydroxyl groups and the formation of aromatic C = C skeleton [47].…”

Non-Destructive Extraction and Separation of Nano- and Microplastics from Environmental Samples by Density Gradient Ultracentrifugation

“…Except for PMMA, other plastic particles were irregular (Figure S1). These NMPs were chosen due to their wide availability either from household products, laboratory items, or real environmental samples. , Polystyrene nanoplastics (2.5% (w/v), density = 1.047 g/mL) were purchased from Aladdin Co., with a particle size of 50–100 nm as shown in the diagram (Figure S2), and CsCl salts were purchased from Ron’s Reagents in AR grade. NaCl, NaBr, MgSO 4 ·7H 2 O, and ZnCl 2 salts were purchased from Sinopharm in AR grade.…”

Development and Verification of Conformer-Specific Vibrational Spectroscopy

“…The Journal of Physical Chemistry A pubs.acs.org/JPCA Article and oxetane isomers with no available intermediate state; 33,34 this is because of the difficulty in experimentally separating the two isomers from the solution with azeotropic composition. 35 The results show that the summed isomer-specific vibrational spectra of acetone and oxetane in the S 0 and the D 0 states, respectively, can represent the IR-resonant VUV-PI and onephoton VUV-MATI spectra of the binary mixture under the supersonic expansion condition.…”

“…In this study, we demonstrate IR dip/hole-burn VUV-MATI spectroscopy to investigate the structures of individual conformers in both states, considering that the previous studies focused on only the S 0 state. The invented conformer-specific vibrational spectroscopic techniques are tested by measuring the isomer-specific vibrational spectra in the S 0 and the D 0 states for the binary mixture in the gas-phase of acetone and oxetane isomers with no available intermediate state; , this is because of the difficulty in experimentally separating the two isomers from the solution with azeotropic composition . The results show that the summed isomer-specific vibrational spectra of acetone and oxetane in the S 0 and the D 0 states, respectively, can represent the IR-resonant VUV-PI and one-photon VUV-MATI spectra of the binary mixture under the supersonic expansion condition.…”