Preconcentration and Determination of Trace Cu, Pb, and Zn in Biological Samples by Combining Carbon Nanofibers (CNFs) as a Solid Phase Extraction Adsorbent with ICP-MS

A procedure for the determination of trace Cu, Pb, and Zn in biological samples has been developed using inductively coupled plasma mass spectrometry (ICP-MS) and carbon nanofibers (CNFs) as a solid phase extraction adsorbent. The effect of various experimental parameters, such as pH, sample flow rate and volume, elution solution and interfering ions on the retention of the studied ions, have been investigated systematically. The experimental results showed that Cu, Pb, and Zn were quantitatively sorbed on a microcolumn containing CNFs in the range of pH 7.0-9.0 and then eluted completely with 1.0 mol mL(-1) HNO3. The detection limits (DL) for Cu, Pb, and Zn were 0.031 ng mL(-1)), 0.027 ng and 0.062 ng mL(-1), respectively. The relative standard deviations (RSD) were less than 5.0% (c=1.0 ng mL(-1), n=9). The proposed method was applied to the determination of trace Cu, Pb, and Zn in a mussel certified reference material (GBW 08571) with satisfactory results.