铜在弱氨性溶液中和α-联糠肟(又:α-糠偶酰二肟,)形成棕色沉淀,这个沉淀能溶解在氯仿、苯和二氧已环中。钴和镍在这个条件下也形成沉淀,沉淀能溶解于有机溶剂中。铜钴镍和α-联糠肟形成的络合物其不稳定常数在50%的二氧已环溶剂里彼此比较接近,但是铜能借助于反萃取的方法和钴、镍分离。 Copper forms a brown precipitate in a weak ammonia solution and a-furyl oxime (again: α-furildioxime), which precipitate can be dissolved in chloroform, benzene and dioxane. Cobalt and nickel also form a precipitate under this condition, and the precipitate can be dissolved in an organic solvent. Copper-cobalt-nickel complexes with α-bismuth oxime have unstable constants that are close to each other in a 50% dioxane solvent, but copper can be separated from cobalt and nickel by means of back-extraction.