A REUSABLE OPTICAL SENSING LAYER FOR PICRIC ACID-BASED ON THE LUMINESCENCE QUENCHING OF THE EU-THENOYLTRIFLUOROACETONE COMPLEX

A new luminescene sensing layer for the determination of picric acid b ased on reversible luminescence quenching of the Eu-thenoyltrifluoroac etone (TTA) complex was proposed. The optosensor was based on the elec trostatic immobilization of the Eu-TTA complex on the chelating resin of Chelex 100 packed in the flow cell, which can induce a room tempera ture luminescence behaviour in an aqueous phase. The quenching mechani sm was also studied. The detection limit was 2 X 10(-6) M by using a r esponse time of 1 min. The optosensor was easy to prepare and the life time of the optosensor was at least 1 month. The optosensor has been u sed for the direct determination of picric acid in water samples and t he indirect measurement of some drugs such as quinine.