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. The effective immobilisation of sulphonated nitrosonaphthols was achieved in the range of pH of 3 - 8, while the adsorption of the monosulphonated reagent (nitroso-N-salt) is twice as high as the disulphonated analogues (nitroso-R-salt and nitroso-K-salt). The adsorption of Cu(II), Fe(III), Co(II), Ni(II), Al(III), Zn(II), Pb(II), Mn(II), and Cr(III) on prepared complexing adsorbents under static and dynamic conditions was studied as a function of time, pH, sample volume, and presence of interfering ions. Metal ions can be desorbed by using 1 M HCl or 1 M HNO3. The preconcentration factors of metals under optimized conditions are varied from 20 to 80. The developed method was used for the preconcentration of trace metals from natural waters followed by ICP-OES determination. The sub-ppb limits of detection of metals are achieved.

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Functionalized adsorbents with poly-(4,9-dioxododecane-1,12-guanidine) (SiO2-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...

Silica modified with 2-nitroso-1-naphthol-4-sulfonic acid (NNS), quantitatively extracting palladium(II) from solutions in the pH range 1-8, is proposed for the preconcentration and photometric determination of palladium(II) in the adsorbent phase. In the sorption of palladium(II) from solutions with pH 1-3, complex compounds of the stoichiometry Pd : NNS = 1 : 2 were formed on the adsorbent surface. They has intense lilac color and a maximum in diffuse reflectance spectrum at 550 nm. A procedure is developed for sorption-photometric determination of palladium in the version of diffuse reflectance spectroscopy with a limit of detection 0.03 μg per 0.1 g of the sorbent. The analytical range is 0.1-10 μg/0.1 g. The procedure was tested in the determination of palladium in wastewater and water extract from the soil.

A simple and available method for on-line preparation of the adsorbent and solid phase extraction procedure for multi-element determination by inductively coupled plasma mass spectrometry (ICP-MS) has been proposed. The adsorbent (Al 2 O 3 -PB-AC) was synthesised by sequential impregnation of Al 2 O 3 with Polybrene (PB) and Alizarin Complexone (AC). Cd(II), Cr(III), Ni(II), Pb(II) and Zn(II) were quantitatively recovered using Al 2 O 3 -PВ-AC from aqueous solutions at pH 6.5 and at a flow rate of 1.0 mL min −1 . All the elements can easily be eluted by 3.0 mL 0.5 M HNO 3 . A mini-column packed with 0.100 g Al 2 O 3 -PB-AC retained all elements quantitatively from up to 50 mL multi-element solution with an enrichment factor of 16.7. The relative standard deviation for five replicate determinations was 3.5%, 7.3%, 6.2%, 7.4% and 4.7% for Cd(II), Cr(III), Ni(II), Pb(II) and Zn(II), respectively, for determination of 5 μg L −1 level. The developed method was applied for SPE-ICP-MS determination of Cd, Cr, Ni, Pb, Zn in snow and river waters.