Persistence of copper-based nanoparticle-containing foliar sprays in Lactuca sativa (lettuce) characterized by spICP-MS

Author(s)
Stephanie Laughton, Adam Laycock, Frank von der Kammer, Thilo Hofmann, Elizabeth A. Casman, Sónia M. Rodrigues, Gregory V. Lowry
Abstract

Copper oxide and hydroxide nanoparticles (Cu-NPs) are components of some commercial pesticides. When these Cu-NPs dissolve in the environment, their size distribution, efficacy, and toxicity are altered. Since acute toxicity screens typically involve pristine NPs, quantification of the transformation of their size distribution in edible leaf vegetables is necessary for accurate consumer risk assessment. Single particle ICP-MS was used to investigate the persistence of three forms of Cu-NPs following foliar application to live lettuce (Lactuca sativa): CuO NP, Cu(OH)2 NP, and Kocide 3000®. A methanol-based digestion method was used to minimize Cu-NP dissolution during extraction from the leaf tissues. After dosing, the NPs associated with the leaf tissues were characterized over a 9-day period to monitor persistence. Nanoparticle counts and total copper mass concentrations remained constant, though the particle size distributions shifted down over time. Washing the leaves in tap water resulted in removal of total copper while the number of Cu-NPs remaining depended on the form applied. This work indicates that washing of lettuce preferentially removed dissolved Cu over Cu-NPs, and that the amount of residual Cu-NPs remaining is low when applied at the recommended rates for Kocide 3000®.

Organisation(s)
Department of Environmental Geosciences
External organisation(s)
Carnegie Mellon University, University of Aveiro
Journal
Journal of Nanoparticle Research
Volume
21
No. of pages
13
ISSN
1388-0764
DOI
https://doi.org/10.1007/s11051-019-4620-4
Publication date
08-2019
Peer reviewed
Yes
Austrian Fields of Science 2012
104023 Environmental chemistry, 105906 Environmental geosciences, 210004 Nanomaterials
Keywords
ASJC Scopus subject areas
Condensed Matter Physics, Bioengineering, Atomic and Molecular Physics, and Optics, General Chemistry, General Materials Science, Modelling and Simulation
Portal url
https://ucrisportal.univie.ac.at/en/publications/f15ee4a8-b84b-4d8d-9abd-0e47aab565a0