Study on spectrophotometric determination of strontium with dibromo-p-methylsulfonazo and its application

The chromogenic reaction between the new reagent dibromo-p-methylsulfonazo and strontium?was studied.In 0.72 mol/L H_2SO_4 medium,strontium reacts with the reagent to form a blue complex which exhibits an absorption maximum at 626 nm with a apparent molar absorptivity of 6.22×10~4 L· mol~(-1)·cm~(-1).Beer's law was obeyed in the range of 0-12 μg/25 mL for strontium.Most of common coexisting ions did not interfere with the determination of strontium.The proposed method has been applied to the direct determination of strontium in Si-Sr-Fe alloys.