Direct spectrophotometric determination of bismuth in pharmaceutical products using a flow-injection system

A sensitive flow-injection method has been developed for the determination of bismuth(III), based on the rapid reaction of bismuth(III) with a chromog enic reagent, dibromo-p-chlorocarboxyarsenazo (DBCCA). The reaction is foll owed spectrophotometrically by measuring the absorbance of bismuth(III)-DBC CA complex at 628 nm. The calibration graph is linear over the range 0.3 to 5.0 mug ml(-1) of bismuth(III). The detection limit is 0.056 mug ml(-1). T he proposed method permits the analytical frequency of 90 h(-1) and has bee n successfully applied to the determination of bismuth in two pharmaceutica l products.