Indexed on: 05 Jun '20Published on: 05 Jun '20Published in: Environmental Toxicology and Chemistry
Recent studies investigating the influence of carbon nanotubes (CNT) on the bioavailability of organic contaminants have mostly focused on single-solute systems; however, a more likely scenario in the natural environment is a multi-solute system where chemical interactions at the surface of the CNT may alter the bioavailability of these chemicals. In this study bi-solute adsorption isotherms of pairs of chemically similar polycyclic aromatic hydrocarbons (PAHs) by multi-walled carbon nanotubes (MWCNTs) were established, in conjunction with quantifying the bioavailability of the two competing MWCNT-adsorbed PAHs to Pimephales promelas using bile analysis by HPLC with fluorescence detection. Results showed that while adsorption and bioavailability of chemically similar PAHs (anthracene and phenanthrene, and fluoranthene and pyrene) were the same in a single-solute system, in bi-solute systems, PAHs that could better align or flex with the MWCNT surface due to morphological characteristics would outcompete the more rigid or planar PAHs. Bioavailability of individual PAHs in bi-solute solutions increased by as much as 50% compared with single-solute solutions. However, the relationship between adsorption (i.e. K ) and concentration of PAH in the fish bile was similar in single and bi-solute systems. This indicates that competitive interactions at the surface of MWCNT influence bioavailability by way of altering adsorption affinity in a moderately predictable manner. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.