The synthesis of new reagent dibromo-p-methyl-carboxysulfonazo and the study on its spectrophotometric determination with strontium

A new reagent dibromopmethylcarboxysulfonazo has been designed and synthesized.The color reaction of the new reagent with strontium has been studied and reported.In 048?mol/L HCl medium,the new reagent dibrompmethylcarboxysulfonazo reacts with strontium to form a blue complex,having an absorption maximum at 620?nm with a molar absorptivity of 888×104 L·mol-1·cm-1.Beers law is obeyed in the range 0～25?μg of strontium in 25?mL of solution.It is found that dibromopmethylcarboxyonazo is a highly sensitive and selective chromogenic reagent in comparison with other reagents when dertermining strontium.