Multielement Solid Phase Preconcentration Using a Chelating Resin of Styrene Divinylbenzene Copolymer and Application for the Analysis of Seawater and Fish Otoliths by Inductively Coupled Plasma Mass Spectrometry (ICP-MS)

Abstract

A new chelating resin was synthesized by immobilizing 4–(2–thiazolylazo) resorcinol (TAR) on to a styrene divinylbenzene copolymer. This material was examined for on-line solid phase extraction/preconcentration of Cd, Co, Cu, Ni, Pb, and Zn in seawater and fish otoliths for determination by inductively plasma mass spectrometry (ICP-MS). A volume of 5.0 mL sample solution was loaded on to a mini-column of the resin at 2.0 mL min−1 via a sequential injection system. The optimum pH for multielement preconcentration was around pH 5.5. Recoveries were better than 96% in artificial seawater. Elution was achieved with 1.0 mL of 0.75 mol L−1 HNO3. The resin possesses a large sorption capacity ranging from 82.0 µmol g−1 for Pb to 319 µmol g−1 for Cu. The detection limits (3σ) varied between 0.0016 µg L−1 (Cd) and 0.015 µg L−1 (Zn) for preconcentration of 5.0 mL blank solutions (pH 5.5). Relative standard deviation for three replicate runs was between 0.3% (Cd) and 6% (Zn) at the 1.0 µg L−1 level. The procedure was validated by analysis of a nearshore seawater and a fish otoliths certified reference material, and employed for coastal seawater and estuarine water samples.