[Study on the synthesis of a new reagent 3-(4'-fluorophenyl)-5-(2'-arsenoxylphenylazo)-rhodanine and the fluoresence determination of bismuth(III)].

A new fluorescence reagent, 3-(4'-fluorophenyl)-5-(2'-arsenoxylphenylazo)-rhodanine, was synthesized. The structure of the reagent was clarified by elemental analysis and IR. At pH 5.4, the reagent can react with trace bismuth (III) to form a chelate which reduces the fluorescence intensity greatly. And when lambdaex/lambdaem = 305/407 nm, the fluorescence is intensive. There is a linear relationship between the decrease of fluorescence intensity and the concentration of bismuth (III) in the range of 0-0.025 microg x mL(-1). The detection limit is 1.2 x 10(-10) g x mL(-1). A new method of fluorescence spectrophotometric determination of bismuth (III) was developed.