二溴对甲基偶氮氯磺与锶的显色反应研究及应用

Study on the Chromogenic Reaction of Dibromo-p-methyl-chromosulfonazo with Strontium and Its Analytical Application

研究了二溴对甲基偶氮氯磺与锶的显色反应,在0.72mol·L-1盐酸介质中,试剂与锶形成稳定的2∶1蓝色络合物,其最大吸收波长位于633nm,表观摩尔吸光系数为7.7×104L·mol-1·cm-1,锶量在0～30μg/25mL范围内符合比耳定律。该试剂与其它测定锶的试剂相比,具有灵敏度高、选择性好等优点。方法应用于铝合金中微量锶的测定,结果满意。

The chromogenic reaction of dibromo-methyl-chromosulfonazo with strontium has been studied in this paper. In 0.72 mol·L^(-1) HCl medium , the reagent reacts with strontium to form a 2∶1 blue complex, having an absorption maximum at 633 nm with a molar absorptivity of 7.7×10~4 L·mol^(-1)·cm^(-1).Beer's law is obeyed in the range 0～30 μg of strontium in 25 mL of solution. It is found that dibromo-p-methyl-chromosulfonazo is a highly sensitive and selective chromogenic reagent in comparison with other reagents when determining strontium. The method has been applied to the determination of strontium in aluminium alloy with satisfactory results.