A sensitive and selective bulk optode for determination of Hg(II) based on hexathiacyclooctadecane and chromoionophore V

A sensitive new bulk optical sensor (optode) for mercury(II) is described. This optode is based on the interaction of hexathiacyclooctadecane with Hg(II) in plasticized polyvinyl chloride (PVC) membrane incorporating chromoionophore V as lipophilic H+-selective indicator. The membranes were cast onto glass substrates and used for the determination of mercury ions in aqueous solutions. The PVC membrane composition plus the other experimental variables were optimized. With the proposed sensor, mercury(II) can be measured in the range of 2.1 × 10−7 to 1.2 × 10−4 mol L−1 with a limit of detection 2.0 × 10−7 mol L−1 Hg(II). The influence of potential interfering ions on the determination Hg(II) was studied. The sensor showed excellent selectivity for Hg(II) with respect to several common alkali, alkaline earth and transition metal ions. The results obtained for the determination of mercury ions in water samples using the proposed optode was found to be comparable with the well-established furnace atomic absorption method.