A Novel Fluorimetric Bulk Optode Membrane Based on NOS Tridentate Schiff Base for Selective Optical Sensing of Al3+ Ions

Abstract

© 2016, Springer Science+Business Media New York. A novel fluorimetric optode has been developed for the highly selective and sensitive for the determination of ultra trace amounts of Al3+ions. The proposed fluorescent optode is based on the incorporation of a simple and effective fluorescent sensor tridentate NOS Schiff base N-(2-hydroxynaphthylidene)-2-aminothiophenol (H2L) in a plasticized PVC containing KTpClPB as a lipophilic anionic additive. H2L was synthesized by a facile one-step Schiff base reaction. The plasticized PVC-membrane displays a calibration response for Al3+ions over a wide concentration range from 1.0 × 10−9to 4.4 × 10−3 mol/L. The fluorescence signal of the optode membrane can be easily recovered by immersion in 0.01 M EDTA. In addition to high stability and reproducibility, the sensor shows a unique selectivity towards Al3+ion with respect to common co-existing cations, particularly Ga3+and In3+. The proposed optode was applied successfully for determination of Al3+in some real samples, including bottled drinking waters, bottled mineral waters and soft drinks.