Siberian Federal University

Silicas, sequentially modified with polyhexamethylene guanidine and 8-hydroxyquinoline‑5-sulfonic acid (SiO2-PHMG‑oxine) or 7-iodine‑8-hydroxyquinoline‑5-sulfonic acid (SiO2-PHMG‑ferron), have been proposed for the adsorption-luminescent determination of Y(III) in natural waters. Complex compounds of Y(III) are formed on the surface of adsorbents during adsorption from solutions at pH 6–7, which luminesce in a yellow-green color (λlum = 485 nm (SiO2-PHMG‑oxine) and λlum = 490 nm (SiO2-PHMG‑ferron)). This is the basis for the method of its sorption-luminescent determination. The detection limit of Y(III), calculated according to the 3s criterion, is 1 μg/L (SiO2-PHMG‑oxine) and 2 μg/L (SiO2-PHMG‑ferron), the analytical range is 4–400 μg/L (SiO2-PHMG‑oxine) and 6–500 μg/L (SiO2-PHMG‑ferron). The developed methods were tested in the determination of yttrium in the Yenisei and Kacha rivers of the Krasnoyarsk Krai