A rapid magnetic-based purification of Cd2+and Pb2+prior to portable electrochemical determination for grain

How to quickly separate and detect cadmium (Cd2+) and lead (Pb2+) from solid samples is a difficult problem that needs to be solved. For this, Fe3O4@agarose@iminodiacetic acid (IDA) was synthesized and used for rapid purification of Cd2+ and Pb2+. This material can remove complex matrix interference completely within a short time of 15 min. The mechanism of the adsorption kinetics fit well to a pseudo-second-order model. A portable screen-printed electrodes (SPEs)-based electrochemical detection platform was established. After coupling with the pretreatment, the whole detection process only took within 30 min. The limits of detection (LOD) were ten times lower than those of the Codex general standard, with values of 0.02 and 0.01 mg/kg for Pb2+ and Cd2+, respectively. The recoveries ranged from 84.1% to 109.7% in naturally contaminated grain, in good agreement with the ICP-MS, demonstrating great prospects for the rapid screening and monitoring of Cd2+ and Pb2+ in grain.