Distribution constants and group increments of organic substances in the extraction systems of water saline–hexane

Abstract

In the extraction systems of hexane–aqueous solutions of potassium carbonate, ammonium sulfate and sodium chloride, the distribution of a number of organic compounds (benzyl alcohol, tetrahydrofuran, phenol, aniline, pyridine, pyridazine, pyrimidine, n-butylamine, diethylamine, triethylamine, benzylamine) was studied. It was shown that sodium chloride, the most frequently used as a salting out agent, is noticeably inferior in salting ability to potassium carbonate, dipotassium phosphate and ammonium sulfate, since it contains singly charged ions with a relatively low charge density. Using the method of group increments on the example of aliphatic alcohols, the salting out ability of a number of mineral salts with singly charged ions was evaluated. By the value of this ability, the salts studied are arranged in the following order: NaNO2 > NaCl > KCl ~ NaBr > NaClO4 > KJ > NH4NO3 > NH4SCN. At the same time, the salting out effect of the last four salts from the above series is small. Based on the usage of the group increment method, the nature of the salting out effect is additionally confirmed, which consists, first of all, in strengthening the structure of the saline solution and increasing the increment of the methylene group (ICH2) with increasing the salt concentration.