An optode for determination Hg(II) ion has been developed using diphenylcarbazone (DC) immobilised in a Nafion(R) film. The film is transparent, homogeneous and mechanically strong, and changes in colour from orange to violet in the presence of Hg(II). The optode film can be generated readily using an acid solution. The optode has been incorporated into flow system, and characterised for determination of Hg(II) in the concentration range 0.5-50 muM with detection limit 0.2 muM (or 40 mug L-1). The response time of the optode film was within 8-15 min to reach 90% of the final signal and depends on the concentration of Hg(II) ions. Interferences from other ions have also been investigated.
Sensor Research Group at Faculty of Pharmacy, University of Jember