ANALYTICAL APPLICATION OF ION ASSOCIATES OF MOLYBDENUM AND TUNGSTEN WITH 2-HYDROXY-5-BROMOTHIOPHENOL AND HYDROPHOBIC AMINES

The interaction of molybdenum and tungsten of 2-hydroxy-5-halogentiophenol leading to the formation of extractable with chloroform ternary complex has been investigated. As hydrophobic amins aniline, N-methylaniline and N, N-dimethylaniline were used. Conditions for the extraction-photometric determination of molybdenum and tungsten have been found. It was found that the ternary complexes are formed at pHopt. 1.8–5.1. The maximum in the absorption spectrum is observed at 457–538 nm. The molar absorbance coefficient is in the range of (3.4–4.2)•104. This fact can be regarded as an indication that Me(VI) is reduced to Me(V) by the reagent itself during the complex formation