Separation and quantification of metallic nanoparticles using cloud point extraction and spectrometric methods: a brief review of latest applications

Because of their unique physical and chemical properties, the use of metallic nanoparticles (MNPs) has considerably increased in various fields. This has led to a new concern about their presence in the environment. Since their negative effect and potential toxicity impact have been confirmed, scientists focus on the development of different procedures for their detection, identification, characterization and quantification, not only in homogeneous and simple matrices, but also in complex environmental matrices. The current review presents cloud point extractions recently developed and used for the separation/preconcentration of MNPs (such as Ag, Au, CuO, ZnO, and Fe3O4) before their spectrometric quantification. This combination has been shown as a promising alternative for separation/preconcentration and quantification of MNPs in different environmental waters (such as tap, canal, mineral, bottled, lake, river, sea waters, or treated and untreated wastewaters) and some antibacterial products. The reviewed separation procedures have illustrated not only the separation of MNPs from the matrix, but also the separation of MNPs from their metallic ions. After optimization, high preconcentration factors and quantitative recoveries were described in most cases.