Simple in situ preconcentration for electrolyte atmospheric liquid discharge optical emission spectrometric determination of trace cadmium on microplastics

Abstract

The harm of heavy metals of microplastics to organisms mainly comes from the part adsorbed on their surface. A new simple in situ preconcentration was proposed for portable electrolyte atmospheric liquid discharge optical emission spectrometry (ISP-EALD-OES) for convenient on-site analysis of Cd on microplastics, with in situ evaporation for effective preconcentration. A microplastic sample with 1% HNO₃ was centrifuged to dissolve Cd species from the surface, and the Cd in the supernatant was then determined by this method. After optimizing the experimental conditions, the limit of detection (LOD) for Cd was 1.5 ng mL⁻¹ using the corresponding aqueous standard. This could be a new strategy for field analytical chemistry of trace elements on microplastics’ surfaces.