Field Preconcentration of Trace Metals from Seawater and Brines Coupled with Laboratory Analysis Using Flow Injection and ICP-AES Detection

A simple but robust battery powered field sampling unit for the selective in situ preconcentration of trace elements (Cd, Co, Cu, Mn, Ni, Pb and Zn) from natural waters on a commercially available iminodiacetate resin is described. Water samples were filtered (0.45 μm) on-line and passed through twin microcolumns containing the resin Metpac CC-1. This allowed duplicate samples to be preconcentrated in parallel. The microcolumns were then taken to the laboratory and placed in a flow injection manifold coupled to an inductively coupled plasma – atomic emission spectrometer (FI – ICP–AES) for elution and quantitation. The results for CASS-2, a coastal seawater CRM, preconcentrated for 2 h at 0.5 ml min−1, gave good agreement with certified values for Cd, Co, Cu, Mn, Ni and Zn. The preconcentration column has been shown to be applicable to samples in the salinity range 39–156% for Cd, Co, Mn and Zn and the field sampling unit is therefore suitable for the analysis of seawaters and industrial brines (...