How suitable is the gold-labelling method for the quantification of nanoplastics in natural water?

Journal article (2023)

Authors

F. Pirade IHE Delft Institute for Water Education, Sanitary Engineering - CEG
K.M. Lompe Sanitary Engineering - CEG
Javier Jimenez-Lamana Université de Pau et des Pays de l'Adour
Sulalit Bandyopadhyay Norwegian University of Science and Technology (NTNU)
Katharina Zürbes Norwegian University of Science and Technology (NTNU)
Nesrine Bali Norwegian University of Science and Technology (NTNU)
Dušan Materić Universiteit Utrecht, Helmholtz Centre for Environmental Research - UFZ
J.W.A. Foppen Water Resources - CEG
Research Group
Sanitary Engineering (CEG) (TU Delft)
Copyright: © 2023 F. Pirade, K.M. Lompe, Javier Jimenez-Lamana, Sulalit Bandyopadhyay, Katharina Zürbes, Nesrine Bali, Dušan Materić, J.W.A. Foppen
DOI
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https://doi.org/10.2166/aqua.2023.278
ICP-MS Metal labelling Nanoplastics quantification NOM interference
More Info
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Published Date

2023

Language

English

Faculty

Civil Engineering & Geosciences

Department

Water Management

Research Group

Sanitary Engineering

Abstract

Nanoplastics are detected in surface water, yet accurately quantifying their particle number concentrations remains a significant challenge. In this study, we tested the applicability of a gold-labelling method to quantify nanoplastics in natural organic matter (NOM) containing water matrices. Gelatin-coated gold nanoparticles (Au-gel NPs) form conjugates with nanoplastics via electrostatic interaction which produces peak signals which can be translated into particle number concentration using single-particle inductively coupled plasma–mass spectrometry (SP-ICP-MS). We used water samples with various NOM concentrations, with and without the addition of 1 10
7 particle
–1 nanoplastics. Our results indicate that nanoplastics in low NOM samples (,1 mg·C L
1) could be successfully quantified. However, in high NOM samples (.15 mg·C L
1), only 13–19% of added nanoplastics were successfully quantified. Further digestion to remove NOM yielded only 10% of spiked nanoplastics. This discrepancy in high NOM samples could likely be attributed to the competition between nanoplastics and NOM existing in the water sample to bind with Au-gel NPs. Our study highlights the suitability of the Au-gel labelling method for quantifying nanoplastics in low NOM water samples. Nevertheless, further optimization, including pre-digestion steps, is essential to apply this method for high NOM water samples effectively.