在 pH =5的邻苯二甲酸氢钾 -氢氧化钠的缓冲溶液中 ,钴 (II)与双水杨醛乙二胺形成黄色配合物 .该黄色配合物的λmax =380nm ,ε =5 .5x10 3L·mol- 1 ·cm- 1 ,Co(II)的质量浓度为 0～ 4 7mg 10ml时符合比尔定律 .本方法用于测定VB12药物中的钴结果良好 Cobalt (II) forms a yellow complex with the bis-salicylaldehyde ethylenediamine in a potassium hydrogen phthalate-sodium hydroxide buffer solution at pH = 5. The yellow complex has a [lambda] max = 380 nm and a [epsilon] = 5.5xl03L · Mol-1 · cm-1, and Beer’s law is obeyed when the mass concentration of Co (II) is 0-4 7mg 10ml.The method is good for the determination of cobalt in VB12 drug