Fibre optic fluorimetric determination of fluoride ions

Abstract

The reaction between fluoride ions and a complex of calcein blue and zirconium, immobilised on a non-ionic exchange resin Amberlite XAD-4, has been studied with respect to the development of a fibre-optic based fluoride ion sensor. The fluorescence from this complex was enhanced in the presence of fluoride ions, which were detected using optical fibres with the immobilised reagent phase contained in a flow cell. The response to fluoride ions at pH 2.2 was linear in the range 0.11–0.42 mM(2–8 p.p.m.). The reversibility of the reaction has been investigated together with the effect of some foreign ions on the determination of fluoride ions.