Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Assessment of ATR-FTIR spectroscopy with multivariate analysis to investigate the binding mechanisms of Ag and TiO2 nanoparticles to Chelex®-100 or Metsorb™ for the DGT technique
AU - Pouran, H.
AU - Perez Colodrero, R.
AU - Wu, S.
AU - Hix, G.
AU - Zakharova, J.
AU - Zhang, H.
PY - 2020/2/21
Y1 - 2020/2/21
N2 - Studying nanomaterials' ecotoxicology is not new but there are still gaps in our understanding of their fate in the environment. A major challenge is lack of reliable tools to measure available concentrations of nanoparticles (NPs) in soil and water. Diffusive gradients in thin-films (DGT) is a robust technique for measuring the concentrations of trace metals in the environment. We have also shown that it could be potentially developed for measuring ZnO NPs. To further investigate the suitability of DGT for measuring the available concentrations of NPs in soil and water we selected two model nanoparticles, Ag and TiO2, which are widely used and incorporated in different commercial products. We aimed to understand (1) if two of the DGT binding agents, Chelex®-100 and Metsorb™, could irreversibly retain our model NPs and if yes (2) what might be the differences between bound Ag and TiO2 NPs and Ag+ and Ti4+ cations. We used ATR-FTIR spectroscopy for this purpose and analysed the IR spectra using principal component analysis and linear discriminant analysis (PCA-LDA), as our pattern recognition tool. The results show that the DGT resins form chemical bonds with silver and titanium nanoparticles and their ionic forms. PCA-LDA demonstrates that the binding mechanisms are statistically different (95% confidence level) among the treatments. This study indicates DGT's potential for measuring the available concentrations of NPs in the environment and suggests that ATR-FTIR spectroscopy combined with computational analysis could potentially differentiate between chemical species that are retained simultaneously by the DGT device resin layer.
AB - Studying nanomaterials' ecotoxicology is not new but there are still gaps in our understanding of their fate in the environment. A major challenge is lack of reliable tools to measure available concentrations of nanoparticles (NPs) in soil and water. Diffusive gradients in thin-films (DGT) is a robust technique for measuring the concentrations of trace metals in the environment. We have also shown that it could be potentially developed for measuring ZnO NPs. To further investigate the suitability of DGT for measuring the available concentrations of NPs in soil and water we selected two model nanoparticles, Ag and TiO2, which are widely used and incorporated in different commercial products. We aimed to understand (1) if two of the DGT binding agents, Chelex®-100 and Metsorb™, could irreversibly retain our model NPs and if yes (2) what might be the differences between bound Ag and TiO2 NPs and Ag+ and Ti4+ cations. We used ATR-FTIR spectroscopy for this purpose and analysed the IR spectra using principal component analysis and linear discriminant analysis (PCA-LDA), as our pattern recognition tool. The results show that the DGT resins form chemical bonds with silver and titanium nanoparticles and their ionic forms. PCA-LDA demonstrates that the binding mechanisms are statistically different (95% confidence level) among the treatments. This study indicates DGT's potential for measuring the available concentrations of NPs in the environment and suggests that ATR-FTIR spectroscopy combined with computational analysis could potentially differentiate between chemical species that are retained simultaneously by the DGT device resin layer.
KW - Bond strength (chemical)
KW - Data handling
KW - Discriminant analysis
KW - Fourier transform infrared spectroscopy
KW - II-VI semiconductors
KW - Multivariant analysis
KW - Nanoparticles
KW - Pattern recognition
KW - Principal component analysis
KW - Resins
KW - Spectrum analysis
KW - Supersaturation
KW - TiO2 nanoparticles
KW - Titanium dioxide
KW - Trace elements
KW - Zinc oxide
KW - ATR FT-IR spectroscopies
KW - Commercial products
KW - Computational analysis
KW - Diffusive gradients in thin films
KW - Linear discriminant analysis
KW - Multi variate analysis
KW - Nanoparticle (NPs)
KW - Titanium nanoparticles
KW - Chemical analysis
U2 - 10.1039/c9ay02458a
DO - 10.1039/c9ay02458a
M3 - Journal article
VL - 12
SP - 959
EP - 969
JO - Analytical Methods
JF - Analytical Methods
SN - 1759-9660
IS - 7
ER -