We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Formula‐Level Turnover and Homologous‐Series Patterns in Dissolved Organic Matter Associated With Sunlight‐Exposed PLA, PET, PE, and PBAT by Negative‐Ion ESI FT‐ICR Mass Spectrometry
AI summary Read the abstract
Scientists found that sunlight breaks down common plastics (like PLA, PET, PE, and PBAT) into thousands of different dissolved chemical compounds, and the mix changes the longer plastic sits in sunlit water. This matters because these breakdown products, not just microplastic particles themselves, could end up in water supplies, though more testing is needed to confirm health effects.
ABSTRACT Rationale Sunlight exposure can alter plastic‐associated material and generate a filterable dissolved organic matter (DOM) pool containing polymer fragments, oxygenated products, and additives. This study compared the molecular composition and time‐dependent spectral differences of DOM associated with four widely used plastics. Methods Particles of poly(lactic acid) (PLA), poly(ethylene terephthalate) (PET), polyethylene (PE), and poly(butylene adipate‐co‐terephthalate) (PBAT) were dispersed in water and exposed to natural sunlight for 6 or 48 h. After particle removal, DOM was enriched by PPL solid‐phase extraction and analyzed by negative‐ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. Assigned formulas were compared using elemental classes, intensity‐weighted descriptors, van Krevelen distributions, Jaccard similarity, Bray–Curtis dissimilarity, and homologous‐series screening. Results Between 2247 and 4661 molecular formulas were assigned per sample, with maximum absolute mass errors below 0.60 ppm. Relative to corresponding 6‐h spectra, formula numbers were lower at 48 h for PLA (−37.5%) and PET (−39.3%) but higher for PE (+41.8%) and PBAT (+14.0%). Formula‐set similarity was lowest for PET (Jaccard 0.329; Bray–Curtis 0.787) and highest for PBAT (0.712; 0.260). In PLA, a C 3 H 4 O 2 ‐spaced oxygen‐rich series increased from 13.4% to 20.9% of the assigned intensity. A C 10 H 8 O 4 ‐spaced PET‐related series contributed 8.70% at 6 h and 0.17% at 48 h. PET‐48 h was dominated by CHSO formulas, whereas PE showed greater CHNO abundance and higher relative contribution of lower mass oxygenated CH 2 series. PBAT retained the greatest formula‐set overlap between spectra. Conclusions The 6‐ and 48‐h spectra showed distinct polymer‐dependent compositional differences. Homologous‐series analysis provided information beyond van Krevelen statistics, whereas nonexclusive N‐ and S‐containing signals highlighted the need for process blanks, dark controls, and tandem mass spectrometry before source‐specific assignments. Because replicate and matched control spectra were not available in the analyzed dataset, these differences are interpreted descriptively and do not demonstrate chemical formation, disappearance, or sunlight‐specific transformation.
More Papers Like This
Molecular Signatures of Dissolved Organic Matter Generated from the Photodissolution of Microplastics in Sunlit Seawater
AI summary Read the abstract
Researchers incubated polyethylene, polypropylene, and expanded polystyrene microplastics in sunlit seawater and characterized the dissolved organic matter produced as the plastics broke down. The study found that sunlight generated hundreds of unique oxygen-containing chemical products from each plastic type, while virtually none were produced in the dark. Evidence indicates that a single process, photodegradation, can transform simple plastic polymers into a complex array of dissolved organic chemicals in ocean environments.
Molecular fingerprints of dissolved organic matter leached from microplastics over prolonged photochemical aging: Implications for aquatic carbon cycling
AI summary Read the abstract
Researchers used ultra-high-resolution mass spectrometry to identify the dissolved organic molecules that leach from polypropylene, polyethylene, and polystyrene microplastics after prolonged exposure to sunlight. They found that polystyrene released the most diverse array of molecules, many of which could persist in water systems. The study suggests that as microplastics degrade in sunlight, they release non-natural organic compounds that may affect the aquatic carbon cycle from rivers to oceans.
High-Resolution Mass Spectrometry Combined with Reactive Oxygen Species Reveals Differences in Photoreactivity of Dissolved Organic Matter from Microplastic Sources in Aqueous Environments
AI summary Read the abstract
Researchers analyzed the dissolved organic matter that different types of microplastics release into water and how it reacts with sunlight. Plastics with aromatic structures like polystyrene and PET released compounds that broke down faster and generated more reactive oxygen species than polyethylene or polypropylene. Understanding how different plastics chemically alter water quality is important because these released compounds and reactive species can affect aquatic life and the safety of water sources used by people.
Photochemical weathering of polyurethane microplastics produced complex and dynamic mixtures of dissolved organic chemicals
AI summary Read the abstract
Researchers studied how sunlight breaks down polyurethane microplastics in ocean surface waters and what chemical byproducts are released. The study found that photochemical weathering produced complex and constantly changing mixtures of dissolved organic chemicals, with different polyurethane types releasing different compounds. The findings reveal that while sunlight helps degrade microplastics, the resulting chemical cocktails may themselves pose environmental risks.
Insight into chain scission and release profiles from photodegradation of polycarbonate microplastics
AI summary Read the abstract
Researchers studied how sunlight breaks down polycarbonate microplastics in water and what chemicals are released in the process. The study found that UV exposure caused the plastics to fragment into smaller pieces while releasing bisphenol A (BPA) and other potentially harmful organic compounds. Importantly, BPA accounted for only a small fraction of the total chemicals released, suggesting that many unknown degradation products are also entering aquatic environments.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.