Speciation of inorganic selenium in natural water by solid-phase extraction using functionalized silica.

Functionalized adsorbents with poly-(4,9-dioxododecane-1,12-guanidine) (SiO-PDDG) and mercaptophenyl groups (MPhS) were used for the separation of Se(VI) and Se(IV) for the first time. Fixation of PDDG was characterized by capillary electrophoresis and TGA/DSC. The quantitative extraction of Se(VI) proceeded due to anion exchange at pH 3-7.

A new method for highly efficient separation and determination of arsenic species in natural water using silica modified with polyamines.

A simple and highly efficient method for the determination of highly toxic arsenic species using non-covalently aminated silica is proposed. The polyamines including poly(hexamethyleneguanidine), poly(4,9-dioxadodecane-1,12-guanidine), hexadimethrine, and poly(diallyldimethylammonium) were tested as silica modifiers. The prepared adsorbents allow effective preconcentration of anionic species of arsenic from aqueous solutions.

Effective separation of chromium species in technological solutions using amino-immobilized silica prior to their determination.

Amino-immobilized (poly(4,9-dioxadodecane-1,12-guanidine, polydiallyldimethylammonium, hexadimethrin bromide, polyhexamethylene guanidine) silicas were proposed for chromium speciation for the first time. Adsorbents surface was characterized by TGA-DSC, FT-IR, CHN, XRD and SEM analysis. Polyamines were strongly fixed on the silica surface and were not washed off with solutions of 3М HNO and 20 g L NaCl.

Biosilica layer-by-layer modified with polyamines and carboxyarsenazo for REE preconcentration prior to ICP-MS determination in lignites and volcanic fumarole sediment.

Biosilica-based adsorbents prepared from rice husk, sequentially modified with polymeric polyamines and carboxyarsenazo were proposed for the preconcentration of 13 lanthanides, La, Sc, and Y. It is shown that the proposed adsorbent quantitatively extracted rare earth elements (REEs) from solutions with pH 3.5-6.