Analytical Sciences

Abstract − Analytical Sciences, 19(2), 313 (2003).

Determination of Cobalt and Nickel by Graphite-Furnace Atomic Absorption Spectrometry after Coprecipitation with Scandium Hydroxide
Tomoharu MINAMI, Kousuke ATSUMI, and Joichi UEDA
Faculty of Education, Kanazawa University, Kakumamachi, Kanazawa 920-1192, Japan
Trace amounts of cobalt and nickel in a water sample were quantitatively coprecipitated with scandium hydroxide at pH 8.0 - 10.5. Because the coprecipitant could be easily dissolved with 1 mol dm-3 nitric acid, and the presence of up to 10 mg cm-3 of scandium did not interfere with the graphite-furnace atomic absorption spectrometric determination of cobalt and nickel, the volume of the final solution prepared for the determination could be minimized down to 0.5 cm-3. The concentration factor was 400-fold and the detection limits (signal to noise = 2) were 5.0 pg cm-3 of cobalt and 10.0 pg cm-3 of nickel in 200 cm3 of the initial sample solution. The 27 diverse ions investigated did not interfere with the determination in at least a 500-fold mass ratio to cobalt or nickel. The proposed method was successfully applied to the determination of trace amounts of cobalt and nickel in river-water samples.