Study on the Spectrophotometric Determination of Barium with a New Chromogenic Reagent Dibromo-p-methyl-bromosulfonazo and Its Analytical Application

A method for the determination of barium with a new chromogenic reagent dibromo p methyl bromosulonazo has been developed. In 0.72 mol·L -1 HCl medium, barium reacts with the reagent to form a 1∶2 blue complex which has an absorption maximum at 628 nm with a molar absorptivity 9.9×10 4 L·mol -1 ·cm -1 . Beer's law is obeyed in the range 0~25 μg of barium in 25 mL of solution. The method has been applied to the determination of micro amouts of barium in sintered materials of barium titanate with satisfactory results.