51. Solving a chemistry problem

163. 50.00 ml of standard solutions of cobalt (0.30 µg/ml) and nickel (0.10 µg/ml) were placed in two separating funnels, N,N´-diethyldithiocarbamate was added, and the resulting CCl4 complexes were extracted. The extracts were collected and diluted to 10.00 ml CCl4. The optical density of both extracts was measured at 367 and 328 nm in cuvettes l = 1.0 cm and obtained: A367, Co = 0.365; A328, Co=0.100; A367, Ni = 0.186; Az28, Ni = 0.300. A 50.00 ml aliquot of the analyzed solution containing cobalt and nickel was placed in a separating funnel and all reagents were added as for standard solutions. The optical density of the obtained extract (10.00 ml CCl4) was measured at 367 and 328 nm, l = 1.0 cm. Calculate the concentration (mcg/ml) of cobalt and nickel in the analyzed solution according to the given measurement results: A367 = 0.515; A328 = 0.425.