Novel anionic magnetic nanosorbent for the automatic and simultaneous determination of arsenic and antimony by MSPE-HG-ICP-MS

Antimony and arsenic are two pollutants known for their bioaccumulative effects and toxic properties even in low concentrations, therefore there is a need to develop efficient and reliable extraction and preconcentration methods of these analytes in water systems simultaneously. In this work, an online ultratrace extraction and preconcentration methodology for environmental waters was carried out by combining magnetic solid phase extraction (MSPE), hydride generation (HG) and inductively coupled plasma mass spectrometry (ICP-MS). A novel anionic nanosorbent, called M@GONIO, based on graphene oxide and magnetic nanoparticles functionalized with ammonium groups was designed, synthesized, and characterized for MSPE. The developed method was carefully optimized through univariate analysis and response surface methodology based on a central composite design. Under the optimized conditions, the enrichment factors for As and Sb were 84.7 and 84.6, respectively. The intra-day and inter-day precision expressed as relative standard deviation (RSD) were below 5.1% in all the evaluated conditions. The proposed analytical method was successfully validated and applied to the determination of trace of As and Sb in environmental waters from diverse origin.