Raman imaging of microplastics and nanoplastics generated by cutting PVC pipe

Yunlong Luo; Md Al Amin; Christopher T Gibson; Clarence Chuah; Youhong Tang; Ravi Naidu; Cheng Fang

doi:10.1016/j.envpol.2022.118857

Raman imaging of microplastics and nanoplastics generated by cutting PVC pipe

Environ Pollut. 2022 Apr 1:298:118857. doi: 10.1016/j.envpol.2022.118857. Epub 2022 Jan 13.

Authors

Yunlong Luo¹, Md Al Amin², Christopher T Gibson³, Clarence Chuah⁴, Youhong Tang⁴, Ravi Naidu¹, Cheng Fang⁵

Affiliations

¹ Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan, NSW, 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, Callaghan, NSW, 2308, Australia.
² Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan, NSW, 2308, Australia.
³ Flinders Institute for NanoScale Science and Technology, College of Science and Engineering, Flinders University, South Australia, 5042, Australia; Flinders Microscopy and Microanalysis, College of Science and Engineering, Flinders University, Bedford Park, 5042, Australia.
⁴ Flinders Microscopy and Microanalysis, College of Science and Engineering, Flinders University, Bedford Park, 5042, Australia.
⁵ Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan, NSW, 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, Callaghan, NSW, 2308, Australia. Electronic address: cheng.fang@newcastle.edu.au.

PMID: 35033619
DOI: 10.1016/j.envpol.2022.118857

Abstract

The characterisation of nanoplastics is much more difficult than that of microplastics. Herewith we employ Raman imaging to capture and visualise nanoplastics and microplastics, due to the increased signal-noise ratio from Raman spectrum matrix when compared with that from a single spectrum. The images mapping multiple characteristic peaks can be merged into one using logic-based algorithm, in order to cross-check these images and to further increase the signal-noise ratio. We demonstrate how to capture and identify microplastics, and then zoom down gradually to visualise nanoplastics, in order to avoid the shielding effect of the microplastics to shadow and obscure the nanoplastics. We also carefully compare the advantages and disadvantages of Raman imaging, while giving recommendations for improvement. We validate our approach to capture the microplastics and nanoplastics as particles released when we cut and assemble PVC pipes in our garden. We estimate that, during a cutting process of the PVC pipe, thousands of microplastics in the range of 0.1-5 mm can be released, along with millions of small microplastics in the range of 1-100 μm, and billions of nanoplastics in the range of <1 μm. Overall, Raman imaging can effectively capture microplastics and nanoplastics.

Keywords: Logic-based algorithm; Microplastics; Nanoplastics; PVC pipe; Raman imaging.

MeSH terms

Algorithms
Gardens
Microplastics*
Plastics
Polyvinyl Chloride
Water Pollutants, Chemical* / analysis

Substances

Microplastics
Plastics
Water Pollutants, Chemical
Polyvinyl Chloride