Determination of copper, cadmium, manganese and lead in saline water with flow injection and atom trapping atomic absorption spectrometry

Abstract

A flow injection device has been developed to separate Cu, Cd, Mn and Pb from a solution of sodium chloride, thus minimising interference and enabling their accurate determination in high salinity waters such as sea- or estuary water. Micro-columns of Chelex 100 resin were used and parameters of ammonium acetate buffer concentration, pH and the concentration of a buffer flush have been optimised. Close to 100% recovery of the transition elements and 99.8% exclusion of sodium chloride was achieved. Atom trapping atomic absorption spectrometry (ATAAS) was used as the detection technique to determine concentrations of the four elements at four sites on the Severn Estuary. In addition, a water cut-off device has been incorporated to improve the safety of the AT apparatus.