Test determination of Cu(II), Ni(II), and Cr(VI) in a single sample

It was shown that Cr(VI), Ni(II), and Cu(II) can be simultaneously adsorbed on a solid phase consisting of two filled fibrous disks and then determine d visually using organic reagents. One sorbent disk, a fibrous material fil led with an AB-17 anion exchanger, was used to determine chromium by its re action with 1,5-diphenylcarbazide. Another disk filled with an KU-2 cation exchanger was used for the simultaneous sorption of copper and nickel follo wed by the consecutive determination of nickel with dimethylglyoxime and co pper with sodium didethyldithiocarbamate. The conditions were optimized for the determination or nickel in the presence of copper and of copper in the presence of nickel after decomposing its dimethylglyoxime complex with 1 M HCl. The detection limits were 0.02, 0.1, and 0.05 mg/L for Cr, Ni, and Cu , respectively. The time of analysis was no longer that 20 min.