Solid phase extraction of rare earth elements in seawater and estuarine water with 4-(2-thiazolylazo) resorcinol immobilized Chromosorb 106 for determination by inductively coupled plasma mass spectrometry

Abstract

A solid phase preconcentration method has been developed using a new chelating resin prepared by immobilization of 4-(2-thiazolylazo) resorcinol (TAR) on Chromosorb 106. The method was optimized for determination of rare earth elements (REEs) in seawater and estuarine water samples by inductively coupled plasma mass spectrometry (ICP-MS). The effects of various experimental parameters, such as load pH, eluent concentration, sample and eluent flow rates were examined to optimize operating conditions. The REEs were quantitatively retained from saline solutions on a minicolumn of Chromosorb 106-TAR resin at pH5.0 and then eluted with 1.0mL of 1% (v/v) HNO3. The resin possesses large sorption capacity for REEs ranging from 81.1μmolg−1 for Lu and 108μmolg−1 for Nd. Detection limits (3s) varied between 0.06ngL−1 for Pr and 0.31ngL−1 for Ce for preconcentration of 5.0mL blank solutions (pH5.0). The relative standard deviation for triplicate measurements was less than 5% at 0.1μgL−1 level. The method was validated by analysis using a Nearshore seawater certified reference material (CASS-4). The elemental results were comparable with the values reported in literature. The method was verified by analysis of spiked and unspiked coastal seawater and estuarine water samples.