Determination and characterization of Ag-Based nanoparticles in soil and surface water samples by novel single particle inductively coupled plasma mass spectrometry (sp-ICP-MS)

Sizing engineered nanoparticles is now a robust field of science; however, application of available techniques to more complex, natural systems is hindered by numerous challenges including low nanoparticle number concentrations, polydispersity from aggregation, dissolution, and interference from other incidental particulates [1]. sp-ICP-MS as a novel emerging technology, has the potential to address many of analytical challenges when sizing inorganic nanoparticles in environmental matrices [2]. In this work, we investigated the occurrence of Ag-based nanoparticles in soil and surface water samples. Soil and water sampled collected from some industrial places in Isfahan city. Ultrasonic assisted aqueous solvent extraction method was used for re-suspension of adsorbed AgNPs. Then the suspension was analysed with Agilent 7700x ICP-MS in single particle mode. The developed method can be applied in eco-toxicological and risk-assessments studies for Ag based nanoparticles in the soil environment. Surface water samples were prepared by using SDS surfactant and were analysed directly by ICP-MS technique. Using this method, the particle mass and number concentration and the particle size and size distribution of the Ag based nanoparticles spiked to natural soil and water samples could be determined. The recovery of 60 nm Ag based nanoparticles at a spiked concentration of 100 ng kg−1 ranged from 72% - 9% in soil and 84% - 91% in water samples. The repeatability for the determination of the particle size of a 60 nm Ag based nanoparticles in surface water and soil samples were 1.4% and 2.3%, respectively.