Preparation of functional magnetic porous organic polymer as sorbent for mercury speciation followed by HPLC-ICP-MS analysis

Abstract

A novel sulfur-containing functional core–shell magnetic porous organic polymer (Fe₃O₄@BD-TpMA-S-SH MOP) was synthesized as a magnetic solid-phase extraction (MSPE) sorbent for mercury speciation followed by high-performance liquid chromatography (HPLC)-inductively coupled plasma mass spectrometry (ICP-MS) detection. The prepared Fe₃O₄@BD-TpMA-S-SH MOP possessed rich active adsorption sites (S: 25 wt%), high magnetism (39.2 emu g⁻¹) and high adsorption capacity (636, 656, 649 and 366 mg g⁻¹ for Hg²⁺, methylmercury (MeHg⁺), ethylmercury (EtHg⁺) and phenylmercury (PhHg⁺), respectively). Under the optimal conditions, the limit of detection (LOD) of the developed MSPE-HPLC-ICP-MS method was 0.43, 0.55, 0.69 and 1.1 ng L⁻¹ for Hg²⁺, MeHg⁺, EtHg⁺ and PhHg⁺, respectively, with a high enrichment factor (EF) in the range of 346–383-fold. The accuracy of the method was validated, and it was successfully applied for trace/ultratrace mercury speciation in environmental water and fish samples. The developed method has high sensitivity, low LOD, high EF, fast adsorption/desorption dynamics and good matrix resistance ability, showing great applicability in real sample analysis with complex sample matrices.