Solid-phase extraction of Zn(II), Cu(II), Ni(II) and Pb(II) on poly(vinyl chloride) modified with 3-ferrocenyl-3-hydroxydithioacrylic acid, and their subsequent determination by electrothermal atomic absorption spectrometry

A new chelating resin based on poly(vinyl chloride) functionalized with 3-ferrocenyl-3-hydroxydithioacrylic acid has been synthesized and characterized. The resin was used as a packing material in an off-line mini-column solid-phase extraction system for preconcentration of Zn, Ni, Cu and Pb in water samples prior to their determination using electrothermal atomic absorption spectrometry. Analytical parameters such as pH, flow rate and sample breakthrough volume were optimized. The breakthrough volume for 0.2 mu g of analyte using 0.1 g of adsorbent was 60-100 mL, permitting enrichment factors of at least 60. The proposed procedure, validated using a riverine water reference material (SLRS-3), was applied to environmental water samples. The potential for use of the chelating resin to separate interfering ions such as Na, K, Mg and Ca is also explored.