Persistence of copper-based nanoparticle-containing foliar sprays in Lactuca sativa (lettuce) characterized by spICP-MS
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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®.
KeywordsNanoparticle fate Copper nanoparticle Nano-enabled agrochemicals Lettuce Nanoparticle transformation Single particle ICP-MS Environmental issues
This material is based upon work supported by the US National Science Foundation (NSF) and the Environmental Protection Agency (EPA) under NSF Cooperative Agreement EF-1266252, Center for the Environmental Implications of NanoTechnology (CEINT), from the NSF Integrated Graduate Education and Research Traineeship Nanotechnology Environmental Effects and Policy (IGERT-NEEP) (DGE-0966227), and CBET-1530563 (NanoFARM). This study was financially supported by Austrian FFG in the framework of the ERA-NET SIINN project 849880 (NanoFarm). Thanks are also due for the financial support to CESAM (UID/AMB/50017-POCI-01-0145-FEDER-007638), to Portuguese FCT/MCTES through national funds (PIDDAC), and the co-funding by the FEDER, within the PT2020 Partnership Agreement and Compete 2020 (project references in Portugal: SIINN/0001/2014 (NanoFarm) and POCI-01-0145-FEDER-016749 and PTDC/AGR-PRO/6262/2014 (NanoFertil)). S. M. Rodrigues acknowledges the financial support from FCT (Project IF/01637/2013).
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Conflict of interest
The authors declare that they have no conflict of interest.
- Bao D, Oh ZG, Chen Z (2016) Characterization of silver nanoparticles internalized by Arabidopsis plants using single particle ICP-MS analysis. Frontiers Plant Sci 7:32Google Scholar
- E.I. du Pont de Nemours and Company (2006) DuPont Kocide 3000. Wilmington, DelawareGoogle Scholar
- Huang Y, Zhao L, Keller AA (2017) Interactions, transformations and bioavailability of nano-copper exposed to root exudates. Environ Sci Technol 51:9074–9083Google Scholar
- ISO (2017) ISO/TS 19590:2017 Nanotechnologies—size distribution and concentration of inorganic nanoparticles in aqueous media via single particle inductively coupled plasma mass spectrometryGoogle Scholar
- Keller AA, Adeleye AS, Conway JR, Garner KL, Zhao L, Cherr GN, Hong J, Gardea-Torresdey JL, Godwin HA, Hanna S, Ji Z, Kaweeteerawat C, Lin S, Lenihan HS, Miller RJ, Nel AE, Peralta-Videa JR, Walker SL, Taylor AA, Torres-Duarte C, Zink JI, Zuverza-Mena N (2017) Comparative environmental fate and toxicity of copper nanomaterials. NanoImpact 7:28–40CrossRefGoogle Scholar
- Ma R et al (2014) Sulfidation of copper oxide nanoparticles and properties of resulting copper sulfide. Environ Sci: Nano 1(4):347–357Google Scholar
- May TW, Wiedmeyer RH (1998) A table of polyatomic interferences in ICP-MS. Atom Spectrom 19(5):150–155Google Scholar
- Peters RJB et al (2014) Development and validation of single particle ICP-MS for sizing and quantitative determination of nano-silver in chicken meat characterisation of nanomaterials in biological samples. Anal Bioanal Chem 406(16):3875–3885Google Scholar
- Rodrigues SM, Demokritou P, Dokoozlian N, Hendren CO, Karn B, Mauter MS, Sadik OA, Safarpour M, Unrine JM, Viers J, Welle P, White JC, Wiesner MR, Lowry GV (2017) Nanotechnology for sustainable food production: promising opportunities and scientific challenges. Environ Sci-Nano 4(4):767–781CrossRefGoogle Scholar
- U.S. EPA (1996) Method 3050B: acid digestion of sediments, sludges, and soils. Revision 2Google Scholar
- Wang Z et al (2013) Biological and environmental transformations of copper-based nanomaterials. Am Chem Soc Nano 7(10):8715–8727Google Scholar