Publications by authors named "Mo-Hai Shen"
Hollow fiber supported liquid membrane (HFSLM) extraction was coupled with ICP-MS for speciation analysis of labile Ag(I) and total Ag(I) in dispersions of silver nanoparticles (AgNPs) and environmental waters. Ag(I) in aqueous samples was extracted into the HFSLM of 5%(m/v) tri-n-octylphosphine oxide in n-undecane, and stripped in the acceptor of 10 mM Na2S2O3 and 1 mM Cu(NO3)2 prepared in 5 mM NaH2PO4-Na2HPO4 buffer (pH 7.5).
View Article and Find Full Text PDFIt is still not very clear what roles the various Ag species play in the toxicity of silver nanoparticles (AgNPs). In this study, we found that traditional exposure media result in uncontrollable but consistent physicochemical transformation of AgNPs, causing artifacts in determination of median lethal concentration (LC50) and hindering the identification of Ag species responsible for the acute toxicity of AgNPs to Daphnia magna. This obstacle was overcome by using 8 h exposure in 0.
View Article and Find Full Text PDFArticle Synopsis
- - Understanding how natural organic matter (NOM) and metal ions (like Na(+), Ca(2+), and Mg(2+)) affect the stability of engineered nanoparticles (ENPs) in water is crucial for environmental science.
- - The study examined how the size (molecular weight) of NOM impacts the aggregation of fullerene nanoparticles (nC60) when treated with different electrolytes, finding that higher molecular weight NOM tends to stabilize nC60 in low salt concentrations but can increase aggregation in high salt environments.
- - The research highlights that the role of high molecular weight NOM can shift from stabilizing ENPs in monovalent (single-charge) conditions to promoting their attachment in divalent (double-charge)
Article Synopsis
- The increase in commercial use of silver nanoparticles (AgNPs) raises concerns about their health and environmental risks, particularly due to their unstable nature in aquatic systems.
- This study examined how factors like sunlight, dissolved organic matter (DOM), and other environmental elements affect the transformation and toxicity of AgNPs.
- Findings showed that sunlight can cause AgNPs to aggregate or break down, and that DOM plays a crucial role in stabilizing them, highlighting the need for more comprehensive toxicity studies under realistic environmental conditions.