Experimental design methodology applied to mercury determination: hair samples as a mercury bioindicator.

The application of modified magnetic nanoparticles in extraction of trace Hg was investigated. For this purpose, surfaces of magnetic nanoparticles were modified by 2-picolamine and then utilized as a solid-phase sorbent for Hg(II) extraction. A statistical method, based on surface response design, has been used for the optimization of Hg ion elution from the magnetic nanoparticles. The sorbed Hg ions were eluted quantitatively with 5.5 mL of a solution containing 0.8 M HCl and 0.08 M EDTA after 12 min. The recovery value in this method was 98.6% with RSD of 1.4%, and the obtained LOD was 0.01 ng/mL. The preconcentration factor was calculated to be 179. The method was applied to the determination of hair Hg content for biomonitoring purposes.