New Complexing Polymer Aminothioether Sorbents in the Analytical Control of Recyclable Metal-Containing Raw Material of Rare and Noble Metals

Abstract

The development and use of thioether sorbents for the separation and preconcentration of metals from aqueous solutions are described. The possibilities of initial polymer thioethers in selective preconcentration and the acceleration of sorption through the introduction of nitrogen-containing groups into thioethers are considered. The dependence of the selectivity of sorbents on the nature of radical at the nitrogen atom is revealed. The use of aminothioethers with different substituents at the nitrogen atom enables distinguishing the groups of noble metals, toxic elements of arsenic and selenium subgroups, and a number of nonferrous metals in the presence of large excesses of other elements. A high recovery of the elements to be determined into the sorption preconcentrate and the selectivity of the sorbents help to improve the accuracy of the analysis. Prospects for the use of aminothioethers are considered on an example of sewage waters. It is found that the extraction of small concentrations of elements from large volumes of solutions is more convenient to carry out in dynamics, for which powdered aminothioether sorbents are not suitable. To ensure a possibility of using aminothioethers in dynamics, a “snake in a cage” synthesis method is used, in which the inert granular support is modified with aminothioether moieties. The introduction of aminothioethers with different radicals at the nitrogen atom makes it possible to combine sorbents selective with respect to different groups of elements on one carrier and thus to create a universal sorbent with predetermined properties, aimed at extracting certain metals.