Determination of cerium, yttrium and thorium in environmental samples

Abstract

A method for the determination of Ce, Y and Th in sea water, pore water, suspended matter, sediments and biota is reported. The method involves a double coprecipitation with Mg(OH)₂ and CaC₂O₄ to pre-concentrate Ce, Y and Th from sea and pore water and acid digestion in open vessels to solubilise sediments, suspended matter and biota. The measurement was performed by inductively coupled plasma atomic emission spectrometry. Radiotracers (¹⁴⁴Ce, ⁸⁸Y and ²²⁸Th) were used in different steps to check the chemical yield of the method. Detection limits of 44 ng g^–1(0.005 ng ml^–1) for Ce, 0.62 ng g^–1(0.0003 ng ml^–1) for Y and 15 ng g^–1(0.003 ng ml^–1) for Th in biota and sediments (water) were obtained. Results for the determination of Ce, Y and Th in sea water, pore water, suspended matter, sediments and biota for samples collected in the Tyrrhenian Sea are given. High concentration factors and recoveries were obtained for Ce, Y and Th in various marine environmental samples. Larger sample volumes can be used to increase the concentration factors and to improve the detection limits.