With the aid of combining of benzidine with 4-brominoaniline through triazene group,a new fluorescent reagent bis[3-( 4-Bromobenzene) diazoamino]– biphenyl( BBDB) was synthesized and confirmed by means of infrared spectra. A chelate complex was formed by the reaction between BBDB and Pb( Ⅱ) in a weak basic medium,which resulted in the enhancement of fluorescence. The possible response mechanism of BBDB to Pb( Ⅱ) was discussed. A new spectrofluorimetric method for the determination of trace Pb( Ⅱ) with this ...