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.

Determination of Metals in Natural Waters by Inductively Coupled Plasma Optical Emission Spectroscopy after Preconcentration on Silica Sequentially Coated with Layers of Polyhexamethylene Guanidinium and Sulphonated Nitrosonaphthols.

A series of complexing adsorbents is prepared by coating silica particles with linear polyhexamethylene guanidinium (PHMG) chloride followed by saturation with a number of sulphonated nitrosonaphthols reagents electrostatically retained by positively charged polymer layer. PHMG coated silica is hydrolytically stable even during treatment with 6 M HCl heated up to 50 °C. The adsorption of 1-nitroso-2-naphthol-3,6-disulfonic acid (nitroso-R-salt), 2-nitroso-1-naphthol-4-sulfonic acid (nitroso-N-salt), and 2-nitroso-1-naphthol-3,6-disulfonic acid (nitroso-K-salt) on PHMG modified silica was studied.