Siberian Federal University

Adsorbents based on silica gel with grafted sulfur-containing groups of various nature were proposed for preconcentrating Se(IV). The quantitative extraction of Se(IV) is achieved in the range of 0.5 M HCl – pH 7 by silica gel with thiol and tetrasulfide groups and pH 1–4 by silica gel with dithiocarbamate and thiourea groups with a sorption equilibrium time not exceeding 5 min. In the studied ranges of acidity, there is no sorption of Se(VI) on MPS, MFS, and TSS adsorbents, which makes it possible to separate Se(IV) and Se(VI) using these sorbents. The adsorption capacity for Se(IV) is 0.11; 0.035 and 0.087 mmol/g for MPS, MFS and TSS, respectively