Identification of factors affecting physicochemical fate of metallic - - PowerPoint PPT Presentation

PhD Research

Identification of factors affecting physicochemical fate of metallic nanoparticles in aquatic environments

Frederik Van Koetsem Ghent, 24 February 2011 Promotor: Prof. Gijs Du Laing

1. . Met etall llic en engin ineered nan anopartic icles (E (ENPs)

• Ultrafine particles (1 – 100 nm) containing metals
• Can exhibit size-related properties
• Potential adverse effects on humans & ecosystems

Frederik Van Koetsem – Laboratory of Analytical Chemistry and Applied Ecochemistry – 24 February 2011

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In Introduction

• Fig. Au Nanoparticles
• Fig. ZnO Nanoparticles
• Fig. Ag Nanoparticles

2. . Applic icati tions of

• f meta

etallic ENPs

Frederik Van Koetsem – Laboratory of Analytical Chemistry and Applied Ecochemistry – 24 February 2011

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In Introduction

• To contribute to the identification of factors affecting the

fate of metallic ENPs

• To reveal the kinetics of NPs’ transformation processes
• To study environmental factors affecting remobilization of

adsorbed or precipitated metallic ENPs

• To aid in the development of analytical methods to

quantify metallic ENPs of different sizes

Frederik Van Koetsem – Laboratory of Analytical Chemistry and Applied Ecochemistry – 24 February 2011

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Aim im

• Recently, coupling of chromatographic techniques to an

element specific detector as ICP-MS, e.g.:

• RPC-ICP-MS
• SEC-ICP-MS
• FFF-ICP-MS
• Focus ⇨ optimization of existing analytical procedures
• HDC ⇨ separation of particulate matter of ≠ sizes
• ICP-MS ⇨ measurement of metal content

Frederik Van Koetsem – Laboratory of Analytical Chemistry and Applied Ecochemistry – 24 February 2011

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Analy lytical method development

• Current lab set-up ⇨ HPLC-ICP-MS hyphenated system
• Size calibration with Au NPs
• Method validation & additional analysis @ external labs
• EM techniques (e.g., TEM, SEM)
• DLS
• ζ-potential measurements
• BET
• Etc.

Frederik Van Koetsem – Laboratory of Analytical Chemistry and Applied Ecochemistry – 24 February 2011

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Analy lytical method development

HD HDC

• To contribute to the identification of factors affecting the

fate of metallic ENPs

• To reveal the kinetics of NPs’ transformation processes
• To study environmental factors affecting remobilization of

adsorbed or precipitated metallic ENPs

• To aid in the development of analytical methods to

quantify metallic ENPs of different sizes

Frederik Van Koetsem – Laboratory of Analytical Chemistry and Applied Ecochemistry – 24 February 2011

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Aim im

1. . Phy hysicochemical be behavio ior of

• f meta

etallic ENPs

• Widespread use of NMs in consumer products ⇨ rel

elease in in aq aquati tic, ter terrestr trial, , an and atm atmospheric en envir ironments

Frederik Van Koetsem – Laboratory of Analytical Chemistry and Applied Ecochemistry – 24 February 2011

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Fate of f ENPs re rele leased in into aquatic environments

• ENPs’ unique properties ⇨ unexpected health and/or

environmental hazards

• Few studies

⇰ Strong need for complete life cycle analysis of

• f the

the fat fate an and tra transport t of

• f ENPs in

in the the en envir ironment

• Exposure to ENPs determined by kinetics of several

physicochemical transformation processes

Frederik Van Koetsem – Laboratory of Analytical Chemistry and Applied Ecochemistry – 24 February 2011

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Fate of f ENPs re rele leased in into aquatic environments

• ENPs colloidal stability and mobility, NP sorption, or

aggregation and deposition ⇨ f(ENP surface properties)

• ENP surface properties dependant on, e.g.:
• Temperature
• Ionic strength
• pH
• Particle concentration and size
• Redox reactions and/or association with NOM or

surfactants ⇨ increasing complexity of interactions

Frederik Van Koetsem – Laboratory of Analytical Chemistry and Applied Ecochemistry – 24 February 2011

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Fate of f ENPs re rele leased in into aquatic environments

2. . Exp xperim imenta tal pr prospect

• Collection of different aquatic samples, e.g.:
• ≠ pH, ≠ salinity, ≠ OM content, ≠ redox potential
• Spiking with metallic ENPs
• Analysis via developed analytical toolbox
• Additional monitoring of physicochemical characteristics
• Electrical conductivity, pH, redox potential, etc.
• Behavior ENPs ⇔ characteristics of aquatic samples

⇰id identif ificati tion of

• f pa

paramete ters affe affecti ting fate fate of

• f ENPs in

in rea eal en envir ironmental sa samples

Frederik Van Koetsem – Laboratory of Analytical Chemistry and Applied Ecochemistry – 24 February 2011

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Fate of f ENPs re rele leased in into aquatic environments

• To contribute to the identification of factors affecting the

fate of metallic ENPs

• To reveal the kinetics of NPs’ transformation processes
• To study environmental factors affecting remobilization of

adsorbed or precipitated metallic ENPs

• To aid in the development of analytical methods to

quantify metallic ENPs of different sizes

Frederik Van Koetsem – Laboratory of Analytical Chemistry and Applied Ecochemistry – 24 February 2011

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Aim im

• Environmental changes ⇨ transformation or

remobilization of metallic ENP

• Changing environmental conditions ⇨ study the kinetics
• f processes affecting NP distribution
• Mimicking of these alterations via 16 Microcosm set-ups

(developed by Prof. J Rinklebe)

Frederik Van Koetsem – Laboratory of Analytical Chemistry and Applied Ecochemistry – 24 February 2011

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Kin inetics of f tra ransformation & re remobilization of f ENPs

Microcosm set-up

Frederik Van Koetsem – Laboratory of Analytical Chemistry and Applied Ecochemistry – 24 February 2011

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Kin inetics of f tra ransformation & re remobilization of f ENPs

Frederik Van Koetsem – Laboratory of Analytical Chemistry and Applied Ecochemistry – 24 February 2011

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Thank you fo for your attention

Any questions?