Mixed-ligand complexes of cobalt(II) with hydroxythiophenols (OP) {2-hydroxythiophenol (HTP) and its derivatives (2-hydroxy-5-aminthiophenol (HATP), 4-hydroxy-3-thiolsulfonic acid (HTSA), 4-hydroxy-3-thiolbenzoic acid (HTBA), 4-Nitro-2-hydroxythio­phenol (HNTP)} in the presence of hydrophobic amines (Am) have been studied by spectro­photometric methods. Extraction of mixed ligand complexes is maximal at pH 3.6-6.3. The optimum conditions for the formation and extraction of mixed-ligand compounds have been found and the ratios of components the complexes have been determined. The Beer’s law was applicable in the range of 0.05–3.2 μg/ml. The effect of foreign ions and reagents on the ex­traction was studied. The new method is free from common interferences. A procedure has been developed for extraction – spectrophotometric determination of cobalt in different objects

doi.org/10.32737/0005-2531-2019-4-39-47