PMID- 34904601
OWN - NLM
STAT- MEDLINE
DCOM- 20220127
LR  - 20220127
IS  - 2050-7895 (Electronic)
IS  - 2050-7887 (Linking)
VI  - 24
IP  - 1
DP  - 2022 Jan 26
TI  - Characterizing photochemical ageing processes of microplastic materials using 
      multivariate analysis of infrared spectra.
PG  - 52-61
LID - 10.1039/d1em00392e [doi]
AB  - Microplastics in the environment are an emerging concern due to impacts on human 
      and environmental health. In addition to direct effects on biota, microplastics 
      influence the fate and distribution of trace organic contaminants through 
      sorption and transport. Environmental weathering may influence the rate and 
      extent of chemical sorption. Changes in the surface characteristics of four 
      common plastics including low-density polyethylene (LDPE), high-density 
      polyethylene (HDPE), polypropylene (PP), and polystyrene (PS) were followed under 
      the influence of both artificial light (UV-B) and natural sunlight for up to six 
      months. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) 
      spectra were collected at regular intervals. Principal component analysis (PCA) 
      of the full dataset of UV-B weathered samples (n >500 spectra) simultaneously 
      discriminated plastic type and extent of photochemical weathering. The magnitude 
      of PCA scores correlated with exposure time and the loadings were consistent with 
      surface chemistry changes including photooxidation. Projecting sunlight and UV-C 
      exposed samples onto this PCA model demonstrated that similar chemical changes 
      occurred, albeit at different rates. The results were compared to the carbonyl 
      index (CI) with similar weathering trends indicating PP weathered at a faster 
      initial rate than LDPE and HDPE. We propose that a multivariate approach is more 
      widely applicable than CI as illustrated by PS, which lacked a stable reference 
      peak. Kinetic analysis of the time series indicated that outdoor weathering 
      occurred 5-12 times slower than the artificial exposure used here, depending on 
      the plastic and the light source employed. The results provide unique insights 
      into weathering processes and the photochemical age of naturally weathered 
      plastics.
FAU - Zvekic, Misha
AU  - Zvekic M
AUID- ORCID: 0000-0003-1653-3074
AD  - Applied Environmental Research Laboratories (AERL), Department of Chemistry, 
      Vancouver Island University, 900 Fifth Street, Nanaimo, British Columbia, Canada. 
      Erik.Krogh@viu.ca.
AD  - Department of Chemistry, University of Victoria, PO Box 1700, Stn CSC, Victoria, 
      British Columbia, Canada.
FAU - Richards, Larissa C
AU  - Richards LC
AUID- ORCID: 0000-0002-6871-8946
AD  - Applied Environmental Research Laboratories (AERL), Department of Chemistry, 
      Vancouver Island University, 900 Fifth Street, Nanaimo, British Columbia, Canada. 
      Erik.Krogh@viu.ca.
AD  - Department of Chemistry, University of Victoria, PO Box 1700, Stn CSC, Victoria, 
      British Columbia, Canada.
FAU - Tong, Christine C
AU  - Tong CC
AD  - Applied Environmental Research Laboratories (AERL), Department of Chemistry, 
      Vancouver Island University, 900 Fifth Street, Nanaimo, British Columbia, Canada. 
      Erik.Krogh@viu.ca.
FAU - Krogh, Erik T
AU  - Krogh ET
AUID- ORCID: 0000-0003-0575-7451
AD  - Applied Environmental Research Laboratories (AERL), Department of Chemistry, 
      Vancouver Island University, 900 Fifth Street, Nanaimo, British Columbia, Canada. 
      Erik.Krogh@viu.ca.
AD  - Department of Chemistry, University of Victoria, PO Box 1700, Stn CSC, Victoria, 
      British Columbia, Canada.
LA  - eng
PT  - Journal Article
DEP - 20220126
PL  - England
TA  - Environ Sci Process Impacts
JT  - Environmental science. Processes & impacts
JID - 101601576
RN  - 0 (Microplastics)
RN  - 0 (Plastics)
RN  - 0 (Water Pollutants, Chemical)
SB  - IM
MH  - Aging
MH  - Humans
MH  - Kinetics
MH  - *Microplastics
MH  - Multivariate Analysis
MH  - Plastics
MH  - *Water Pollutants, Chemical/analysis
EDAT- 2021/12/15 06:00
MHDA- 2022/01/28 06:00
CRDT- 2021/12/14 09:42
PHST- 2021/12/15 06:00 [pubmed]
PHST- 2022/01/28 06:00 [medline]
PHST- 2021/12/14 09:42 [entrez]
AID - 10.1039/d1em00392e [doi]
PST - epublish
SO  - Environ Sci Process Impacts. 2022 Jan 26;24(1):52-61. doi: 10.1039/d1em00392e.