Asymmetric flow field-flow fractionation for comprehensive characterization of hetero-aggregates made of nano-silver and extracellular polymeric substances.

Autor: Gasco R; University of Geneva, Faculty of Sciences, Department F.-A. Forel for Environmental and Aquatic Sciences, Environemntal Biogeochemistry and Ecotoxicology, Bvd Carl-Vogt 66, 1211 Geneva Switzerland., Worms IAM; University of Geneva, Faculty of Sciences, Department F.-A. Forel for Environmental and Aquatic Sciences, Environemntal Biogeochemistry and Ecotoxicology, Bvd Carl-Vogt 66, 1211 Geneva Switzerland. Electronic address: isabelle.worms@unige.ch., Santos D; University of Geneva, Faculty of Sciences, Department F.-A. Forel for Environmental and Aquatic Sciences, Environemntal Biogeochemistry and Ecotoxicology, Bvd Carl-Vogt 66, 1211 Geneva Switzerland., Slaveykova VI; University of Geneva, Faculty of Sciences, Department F.-A. Forel for Environmental and Aquatic Sciences, Environemntal Biogeochemistry and Ecotoxicology, Bvd Carl-Vogt 66, 1211 Geneva Switzerland. Electronic address: vera.slaveykova@unige.ch.
Jazyk: angličtina
Zdroj: Journal of chromatography. A [J Chromatogr A] 2025 Jan 04; Vol. 1739, pp. 465507. Date of Electronic Publication: 2024 Nov 07.
DOI: 10.1016/j.chroma.2024.465507
Abstrakt: The present study explores the capability of asymmetrical flow field-flow fractionation (AF4) coupled online with diode array (DAD), fluorescence detectors (FLD), multi-angle light scattering (MALS) and dynamic light scattering (DLS) to characterize silver nanoparticles (nAg) hetero-aggregates formed with diatoms derived extracellular polymeric substances (EPS). The content of EPS varied from 10.5 to 105 mgC L -1 and nAg were dispersed at 4 mg L -1 in a freshwater medium. Good recoveries (∼ 76.9 ± 8.4 %) of nAg-EPS were obtained from AF4-DAD signals, but an anomalous elution was observed as EPS concentration increased: AF4 retention times decreased despite average gyration radii measured by MALS for nAg-EPS increased (from 16 nm to 24 nm), which suggests a change in the aggregation state, as evaluated by UV-Vis scans obtained from DAD. A regular Brownian relaxation of nAg-EPS was proven for each EPS concentration using these 2 detectors. The comparison of on-line and batch DLS measurements validated in addition, that no (dis)aggregation occurs upon injections. After a thorough comparison with classical AF4 using standards, the frit-inlet-AF4 was used. Slightly higher recovery (79.6 ± 4.6 %) was obtained but similar deviation of nAg-EPS elution occurred, excluding the implication of membrane differential fouling of nAg-EPS /conditioning effects of EPS. The investigation of physico-chemical parameters controlling the Brownian relaxation of nAg-EPS suggests the influence of nAg-EPS structure and EPS loading. This study demonstrates the suitable use of AF4 coupled to multiple detectors to probe-out eco-corona formation and characterize polydisperse systems containing NPs, EPS and their hetero-aggregates in freshwaters, even under a non-ideal size-fractionation scenario.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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