Analysis of cerium oxide and copper oxide nanoparticles bioaccessibility from radish using SP-ICP-MS

The transformation of nanoparticles (NPs) internalized in plant tissues is the human digestive system that can provide a better understanding of the impact of NPs on the human system. The presented methodology was developed to study the bioaccessibility of cerium oxide (CeO₂ ) and copper oxide (CuO) NPs from radish after the in vitro simulation of gastrointestinal digestion using single-particle inductively coupled plasma mass spectrometry (SP-ICP-MS).

Radish plants were cultivated hydroponically in a growth medium containing: (i) CeO₂ NPs and (ii) CuO NPs. Both cerium (Ce) and copper (Cu) were found in all organs of the radish plants after analysis by standalone ICP-MS. This confirms the bioaccumulation of CeO₂ and CuO NPs and the translocation of their Ce and Cu to the aerial parts of the plant. Less Ce (4.095 μg g^-1 ) has been detected in leaves than in roots (1.156 mg g^-1 ) while Cu content in leaves was 5.245 μg g^-1 and in roots was 10.41 μg g^-1 . Analysis of the digestive extracts obtained after the in vitro simulation of gastro (pepsin) and gastrointestinal (pancreatin) digestion showed that Ce has easy access to human system at least by 73%.

The size of CeO₂ NPs in digestive extracts showed no significant changes. However, the results obtained for CuO NPs digestion were variable and suggested that CuO NPs dissolved during the digestion process. The CuO NPs were observed in roots after the gastrointestinal digestion concluding that CuO NPs recovered after the initial dissolution. © 2020 Society of Chemical Industry.