Determination of trace Nd, Tb, and Ho in environmental samples by ICP-MS after column preconcentration and separation with titanium dioxide nanotubes

摘要

A microcolumn preconcentration method coupled to inductively coupled plasma mass spectrometry (ICP-MS) was developed for the preconcentration and determination of trace rare earth elements (REE_s) in environmental water samples, based on titanium dioxide nanotubes (TDNTs) as a solid phase extraction adsorbent. The experimental parameters for the preconcentration of REE_s, such as pH, sample flow rate and volume, eluent concentration and interfering ions on the preconcentration of REE_s, were examined systematically. Under the optimum conditions, the detection limits for Nd, Tb, and Ho were found to be 0.093, 0.018, and 0.025 pg mL~1, respectively, with a 100-fold enrichment factor. The relative standard deviations (RSD_ s) were less than 4.6% (n=9, c=1.0 ng mL'1). The proposed method was applied to the determination of trace rare earth elements (Nd, Tb, and Ho) in real samples with satisfactory results. The recoveries were between 93.5% and 104%.