【摘要】 <正>钻的显色剂有数十种之多,其中应用较广的是亚硝基酚类和吡啶偶氮类,如常用的亚硝基红盐法灵敏度较低（ε=1.4×10⁴）。采用〔2-（5-Br-吡啶偶氮）-5-二乙氨基酚)（5-Br-PADAP）作显色剂,由于试剂结构中吡啶环上的吸电子基—Br、苯酚上—N（C₂H₅）₂的斥电子效应使试剂在与金属离子反应时,形成“带电醌型”螯合物而更多还原

【Abstract】 A sensitive and selective photometric method has been developed for the determination of trace cobalt by the formation of co-5-Br-PADAP complex in agueous phase ’with non-ionic surfactant OP as solubilizing agent. The maximum absorption of the complex is at 585nm. This complex stands stably within 24 hours in the presence of sodium pyrophos-phate.This method has been applied to the determination of trace cobalt in ores and steels with satisfactory results.更多还原