电解锰试样用盐酸和过氧化氢溶解,以砷作载体,氯化铜为催化剂,加次磷酸钙还原硒,用苯萃取沉淀与锰和杂质分离。加溴酸钾将砷硒沉淀溶于水相中,除去过量氧化剂后,3·3′-二氨基联苯胺溶液与二氧化硒生成有色配合物,用甲笨萃取,于分光光度计420 nm波长处测量其吸光度。本法准确稳定,测定范围为0.005%—0.05%。 Electrolytic manganese samples were dissolved with hydrochloric acid and hydrogen peroxide to arsenic as a carrier, copper chloride as a catalyst, plus calcium hypophosphite to reduce selenium, with benzene extraction precipitation and separation of manganese and impurities. Potassium bromate dissolves the arsenic and selenium precipitate in the aqueous phase. After removing excess oxidant, the 3 · 3’- diaminobenzidine solution forms a colored complex with selenium dioxide and is extracted with methylbenzene and measured at a wavelength of 420 nm in a spectrophotometer Its absorbance. This law is accurate and stable, the determination of the range of 0.005% -0.05%.