Simultaneous determination of cadmium and zinc using a fiber optic device and fluorescence spectrometry

A reservoir type of optode is described for simultaneous and remote determination of Cd and Zn using [9-(1′,4′,7′,10′,13′-pentaazacyclopentadecyl)methylanthracene] as the fluorophore. Simultaneous analysis was achieved by the significant perturbation in the fluorescence spectrum of the Cd–ligand complex while the Zn complex only results in enhancement in the fluorescence intensity as compared to ligand alone. The ion permeability of several membranes were examined; Nafion and cellophane were used for the construction of the optode. Using the optode constructed with cellophane, for 20 min immersion time, the 3-s detection limits were found to be 4.5 μg l−1 for Cd and 0.6 μg l−1 for Zn.