Determination of rare earth elements in seawater by inductively coupled plasma mass spectrometry with on-line column pre-concentration using 8-quinolinole-immobilized fluorinated metal alkoxide glass

The on-line column pre-concentration technique with inductively coupled plasma mass spectrometry (ICP-MS) has been developed using micro-column of 8-quinolinole-immobilized fluorinated metal alkoxide glass (MAF-8HQ). The aim of method was to determine rare earth elements (REEs) (Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu) in seawater. A 6.4 ml of seawater sample was passed through the column for 2 min, after washing the column with ultrapure water, the adsorbed REEs were subsequently eluted into the plasma with 1.4 M nitric acid. Sample pH, sampling and eluting flow rates and acidity of eluent were optimized. Detection limits (3σ) based on three times standard deviations of water by 8 replicates were in the range from 0.11 pg ml−1 for Y to 0.30 pg ml−1 for Tb, and the precisions by a 10 pg ml−1 REEs standard solution (n=8) were in the range from 4.7% for Tm to 8.7% for Tb and Yb. Analysis of one sample could be processed in 7 min. The proposed method was verified by determination of REEs in the two certified reference materials (CRMs) of seawater, CASS-4 and NASS-5, and the method was also applied to determine REEs in the costal seawater of Hiroshima Bay, the Seto Inland Sea, Japan.