【摘要】 研究了钡的新显色剂二溴对甲偶氮羧的合成及其与钡显色反应的条件。在磷酸介质中，试剂与钡形成2：1的络合物，吸收峰位于609nm。摩尔吸光系数为2．05×104L·mol－1·cm－1。钡量在0～1．6mg／L范围内符合比耳定律，显色体系具有很高的选择性，大量常见离子及40倍量的钙，7倍量的锶不影响测定，可不经分离，直接测定新型除氧剂中的钡，结果令人满意。更多还原

【Abstract】 A new reagent, dibromomethyl carboxyazo was synthesized and its colour reaction with barium was studied. In the medium of H3PO4, this reagent reacts with barium to form a 2: 1 complex with an apparent molar absorptivity of 2. 05 ×10 4L· mol-1·cm-1 at 609 nm.Bcer’s law is obeyed over the range from 0 to 1. 6 mg/L for barium. The method is highly selective, since most foreign ions in considerable amounts, 40-fold amounts of calium and 7-fold amounts of strontium are tolerable. The method has been applied to the direct determination of barium in deoxidant samples with satisfactory results.更多还原