Application of cobalt ammine complexes for the simultaneous determination of traces of As, Fe, Ti, V and Zr in high-purity cobalt metal by lanthanum hydroxide coprecipitation and inductively coupled plasma-atomic emission spectrometry.
Co is not coprecipitated with lanthanum hydroxide in ammonium hydroxide solution due to the formation of soluble salts of cobalt ammine complexes. This complexation reaction has been applied to the simultaneous determination of five trace impurities (As, Fe, Ti, V and Zr) in high-purity Co metal by inductively coupled plasma-atomic emission spectrometry. Warming the solution and double coprecipitation are effective for separating the trace elements simultaneously from a large amount of cobalt ammine complexes. Matrix-matched solutions are used for calibration. The detection limits of the five elements are in the range of 0.06 and 0.6 microg/g and the recoveries are quantitative.
Kujirai
O
O
National Research Institute for Metals, 1-2-1, Sengen, 305, Tsukuba, Ibaraki, Japan.
Yamada
K
K