A compact optical flow cell for use in aqueous halide determination

A compact optical flow cell for use in aqueous halide determination has been developed. The performance of the cell and optical set-up has been tested by studying the halide quenching of fluorescence from thin polymeric films containing a halide-sensitive fluorophore. Aqueous halide is injected into the flow cell and the quenched fluorescence emission observed orthogonal to the plane of excitation after it has undergone total internal reflection within the glass support-an efficient method for observing weak fluorescence intensities. The experimental set-up is both a low-cost and an accurate method for use in the determination of aqueous halide ions. The method can very easily be adopted to determine other aqueous anions which quench the fluorescence of dyes incorporated into thin hydrophilic polymer films. The suitability of this method for the continuous measurement of halide 'on-line' rather than a single 'static' measurement is discussed.