Feasibility study on the extraction of TiO2 nanoparticle exposed in the activated sludge using alkaline digestion

[Display omitted] With increasing of potential toxicity of engineered nanoparticles (NPs), many in-vivo and in-vitro studies have been conducted and required an effective extraction method of NPs from exposed biological samples (tissues or cells). Herein, alkaline digestion using tetramethylammonium hydroxide (TMAH) was applied to extract TiO2 NPs exposed to activated sludge. While TMAH was shown to have high extraction efficiency of Ag NPs, Au NPs, and quantum dots, the recovery of TiO2 NPs from biological samples has not been tested. Therefore, we confirm that TiO2 NPs exposed to activated sludge can be effectively extracted at the initial size distribution using TMAH digestion with sonication.