A Versatile Method for Simultaneous One-Step Preconcentration of Trace Metals and REEs Using InertSep ME-2

Abstract

This study proposes a solid-phase extraction method using InertSep ME-2 resin that enables one-step preconcentration of trace metals and rare earth elements (REEs) across a wide salinity range. Developed as an alternative following the discontinuation of Nobias Chelate PA-1, the method uses a custom system with eight resin columns to process 40-50 mL samples in parallel within 20 minutes. Analysis by ICP-MS, employing matrix-matched bracketing standards along with Y and Lu spikes, achieved high precision (relative standard deviation below 5%) and high recovery rates (trace metals 99 ± 5%, REEs 103 ± 2%). Application to Toyama Bay revealed clear distribution patterns of trace metals and REEs in river water, groundwater, submarine groundwater discharge (SGD), and seawater, demonstrating that SGD plays a significant role in transporting terrestrial metals to coastal areas. This method provides a reliable and efficient approach for trace element analysis in diverse aquatic environments.