Spectrophotometric Determination of Micro Barium in Ferroalloy with Dibromo-p-methyl Carboxyazo

In the medium of HCl, dibromo p methyl carboxyazo reacts with barium to form a 2∶1 complex, the maximum absorption exhibits at 605nm with an apparent molar absorptivity e max = 1.75×10 4L·mol -1 ·cm -1 . The complex is stable at least for 48 hours. The method is highly selective, most foreign ions in considerable amounts are tolerable. Beer's law is obeyed over the range from 0 to 16μg/10mL for barium. The method has been used to the determination of micro barium in ferroalloy samples with satisfactory results.