Determination of trace metals in seawater by on-line column preconcentration inductively coupled plasma mass spectrometry

Abstract

A home made column of commercially available imminodiacetic functional group resin, Muromac A-1 was used to separate and concentrate trace metals (Al, V, Mn, Co, Ni, Cu, Zn, Mo, Cd, Pb and U) from seawater. An automated low pressure flow analysis method with on-line column preconcentration/inductively coupled plasma mass spectrometry (ICP-MS) is described for the determination of trace metals in seawater. Sample solutions (adjusted to pH 5.0) passed through the column, after washing the column with water, the adsorbed metals were subsequently eluted into the plasma with 0.7 M nitric acid. Calibration curves were accomplished by means of purified artificial seawater with a sample loading time of 120 s. Detection limits of the trace metals in the artificial seawater were 0.007 for Al, 0.011 for V, 0.007 for Mn, 0.014 for Co, 0.029 for Ni, 0.099 for Cu, 0.076 for Zn, 0.007 for Mo, 0.010 for Cd, 0.007 for Pb and 0.001 ng ml −1 for U, respectively, as the concentrations of analyte metals corresponding to three times (3 σ) the standard deviation of blank signal intensities by eight replicate measurements. The precision was less than ±5.4% for 11 elements and one sample can be processed in 7 ml and 8 min. The proposed method was verified by the analysis of two reference standard materials of seawater CASS-3 and NASS-4.