K系数-双波长标准加入法测定镀镍溶液中的钴含量

DETERMINATION OF COBALT CONTENT IN NICKEL PLATING SOLUTIONS BY K COEFFICIENT DUAL WAVELENGTH STANDARD ADDITION SPECTROPHOTOMETRIC METHOD

提出了一种Ｋ系数－双波长标准加入法，应用于镀镍溶液中钴的测定．通过加入掩蔽剂氨三乙酸（ＮＴＡ），使得Ｎｉ（Ⅱ）与５－Ｂｒ－ＰＡＤＡＰ形成的配合物的吸光度显著降低，而相对应的Ｃｏ（Ⅱ）配合物的吸光度基本不变．

A new K coefficient dual wavelength standard addition spectrophotometric method is proposed in this paper for determination of cobalt content in nickel plating solutions with satisfactory results.The absorptivity of the complex of Ni(Ⅱ)with 2 (5 Bromo 2 pyridylazo) 5 diethylaminophenol(5 Br PADAP) is lowered by the addition of the masking reagent ammoniatriacetic acid(NTA),while the absorptivity of the corresponding complex of Co(Ⅱ) remains unchanged.So that,the accuracy of the determination is increased of Co(Ⅱ) mixed with large amount of Ni(Ⅱ).