The distribution of the extracted substance between the aqueous and organic phases, among other factors, depends on the diluent chosen. It has already been noted in many works that dilution with alkanes usually increases the extraction capacity of TBP.

Tellurium in the tetravalent state in hydrochloric acid solutions forms moderately strong complexes that absorb in the ultraviolet region. The spectrum consists of a number of bands characterizing various tellurium-containing particles. Solutions with high HCl content (5-10 mol/l) and low tellurium content (10^-6-10^-3 mol/l) have buffering properties. The proportion of different forms of tellurium-containing particles depends little on the total concentration of tellurium and is determined by the concentration of hydrochloric acid.

The distribution of the extracted substance between the aqueous and organic phases depends on the nature of the diluent used. If kerosene or individual alkanes are used as a diluent, i.e. compounds that are slightly polar and do not have the ability to form donor-acceptor bonds, then their interaction with tributyl phosphate (TBP) and solvate is apparently limited by the occurrence of dispersion forces without the formation of molecular compounds with dissolved substances. In such systems, limited solubility of solvates of extracted compounds is very often observed...

The effect of temperature on the distribution of substances in extraction processes has been repeatedly considered. The distribution of coordination-solvated compounds is usually placed in a greater dependence on temperature than the distribution of hydrate-solvates...

Naphthenic acids are good extractants for heavy non-ferrous metal ions, with each metal ion being extracted in a specific region of pH values. It has been shown that Cu2+ copper ions begin to be extracted at a pH of 3.2-3.7, depending on the concentration of copper in the aqueous phase, the concentration of naphthenic acid in the organic phase, and the ratio.

Naphthenic acids are a component of oils, mainly naphthenic ones. The latter contain alicyclic hydrocarbons with five- and six-membered cycles. The composition and structure of naphthenic acids change from one oil fraction to another. Naphthenic acids obtained by alkaline treatment of gasoil and kerosene distillates contain mainly cyclopentane derivatives.