Optical fibre Al(III) sensor based on solid surface fluorescence measurement

An optical Al(III) sensor based on the use of purpurin immobilised on XAD 4 (styrene-divinylbenzene cross-linked copolymer) and solid surface fluorescence measurement has been developed. An optical fibre attachment for the spectrofluorometer and the probe have also been designed in this study. The plot of log[Al(III)] against the sensor response was linear for Al(III) concentration in the range of 5.0×10−5 to 3.2×10−3 M, with a limit of detection of 3.0×10−5 M. Fluoride solution was shown not to quench the complex during measurement and was used as regenerating agent to regenerate the probe. A good repeatability (1%) and reproducibility (4%) of measurement were obtained with this probe.