Field sample preconcentration of copper in sea water using chelating minicolumns subsequently incorporated on a flow-injection-flame atomic absorption spectrometry system

摘要

A field flow preconcentration system for copper etermination in seawater is described.Seawater samples are collected and preconcentrated in site by passing them using a peristaltic pump through a minicolumn packed with Amberlite XAD-4 impreganated with the complexing agent 1-(2-pyridylazo)-2-naphthol.Thus,copper is preconcentrated without the interference of the saline matrix.Once in the laboratory,the minicolumns loaded with copper are incorporated on a flow injection system and eluted with a small volume of a 20%(v/v)ethanolic solution of 0.5 mol L~(-1) hydrochloric acid into the nebuliser-burnery system of a flame atomic absorption spectrometer.The analytical figures of merit for the determination of copper are as follows:detection limit (3s),0.06 #mu#g L~(-1);precision (RSD),1.2% for 2 #mu#g L~(-1);entichment factor,30 (using 25 mL of sample and 83 #mu#L of eluent).Analysis of certified reference materials (SLEW-3 and NASS-5) showed good agreement with the certified value.This procedure was applied to the determination of copper in seawater samples from Galicia (Spain).