An optode for the determination of copper, based on 4-decyloxy-2-(2-pyridylazo)-1-naphthol immobilized in poly(vinyl chloride)

A new ionophore, 4-decyloxy-2-(2-pyridylazo)-1-naphthol (lipophilized iso-PAN), has been synthesized. The ionophore has been immobilized in a poly(vinyl chloride) (PVC) membrane to produce a functioning optode. This membrane is homogeneous, transparent, mechanically strong and reacts with several metal ions to produce deeply coloured complexes which are reversed with the addition of HCl. Conditions have been optimized for the detection of Cu(II) ions in the concentration range 0.2 to 100 muM. The reactions with interfering ions Hg(II), Fe(II), Bi(II), Ni(II), Pb(II), Cd(II), Zn(II) and Al(III) are discussed.