21. Solving a chemistry problem

5. 50 ml of standard solutions of cobalt (0.3 µg/ml) and nickel (0.1 µg/ml) were placed in two separating funnels, N,N´-diethyldithiocarbamate was added and the resulting complexes were extracted with CCl4. The extracts were collected and diluted to 10 ml CCl4. We measured the optical density of both extracts at 367 nm and 328 nm in cuvettes l=1.0 cm and obtained: A367,Co=0.365; A328,Co=0.100; A367,Ni =0.186; A328,Ni =0.300. A 50 ml aliquot of the test solution containing cobalt and nickel was placed in a separatory funnel and all reagents were added as for standard solutions. The optical density of the resulting extract (10 ml of CCl4) was measured at 367 and 328 nm, l = 1.0 cm. Calculate the concentration (μg/ml) of cobalt and nickel in the analyzed solution from the given measurement results: A367 = 0.385; A328=0.310.