Fluorescence determination of platinum with dibromohydroxyphenyl-fluorone in microemulsion after separation and enrichment by sulfhydryl dextrose gel

A new fluorescence quenching method has been developed for the determination of platinum in nonionic microemulsion medium. This method is based oil the fact that platinum can form a stable chelate with dibromohydroxyphenyl-fluorine (DBHPF) when they are in the molar ratio of 1:2 in the nonionic microemulsion medium. Under optimum conditions, the system, having the maximum excitation and emission wavelengths at 468 nm and 532 nm, respectively, shows constant fluorescence intensity in the pH range of 3.5-4.0 and high selectivity and sensitivity as well as low interference from foreign ions. Furthermore, this fluorescence intensity is a linear function of Pt(IV) concentration in the range of 0.002-1.00 μg·mL−1 and the limit of detection is 2.90 ng·mL−1.