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Mesoporous lanthanum phosphate was synthesized by supramolecular self-assembly of cetyltrimethylammonium bromide and lanthanum nitrate following digestion in phosphoric acid. TGA-DTA, XRD and SEM were employed to study the uncalcined and calcined materials. Sorption behavior of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Ba(II), Hg(II) and Pb(II) cations was studied on such materials in water, 3 mol•L -1 ammonia, 0.01 mol•L -1 potassium ferrocyanide and 0.01 mol•L -1 potassium ferricyanide solutions.

In this work, a novel, efficient, and green sorbent, SiO2@Fe3O4 has been created and functionalized with 1‐butyl‐3‐methylimidazolium hexafluorophosphate as an ionic liquid. This sorbent was applied for microextraction of four beta blockers, propranolol, metoprolol, atenolol, and alprenolol with bupivacaine as internal standard from human plasma followed by liquid chromatography with mass spectrometric detection. A mixture of sodium bicarbonate and sodium dihydrogen phosphate was used as an extractant dispersive agent (effervescent power) to enhance the interaction between the magnetic sorbent and analytes. Main affecting parameters on microextraction and elution were optimized. Figures of merit for dispersive solid phase extraction with ionic liquid coated magnetic nanoparticles assisted by effervescent powder were calculated under the optimized conditions. The detection limits for propranolol, metoprolol, atenolol, and alprenolol were found at 0.33, 0.62, 0.03, and 0.44 ng/mL, respectively. For all analytes, good linearity was obtained. Intra‐ (n = 5) and interday (n = 10) precision were both under 6.3% while the preconcentration factors were obtained in the range between 15–18. The extraction efficiencies for each analyte ranged from 75 to 91%. The method was successfully applied for determination of trace amounts of the beta blockers in human plasma samples.

In this paper, new modified magnetite nanoparticles functionalized with triazene groups were designed and synthesized for extraction/preconcentration of sub-ppb level of mercury ions in water and fish samples prior to its determination with inductively coupled plasma optical emission spectrometry (ICP-OES). In the separation process, aqueous solution of Hg 2+ ions was mixed with 150 mg of Fe 3 O 4 magnetite nanoparticles modified with 1-(p-acetyl phenyl)-3-(o-ethoxy phenyl) triazene (AET) and then external magnetic field was applied for isolation of magnetite nanoparticles containing mercury ions. Experimental conditions for effective adsorption including pH, sample volume, eluent concentration and existing co-existing ions have been studied and established. Under the optimal extraction and preconcentration conditions, the limit of detection (LOD) of 0.04 ng mL À1 and the relative standard deviation (R.S.D) of 2.09% for five replicate extractions and measurements of 10 mg of Hg 2+ ion in 1000 mL water solution were achieved by ICP-OES. The sorption capacity of functionalized Fe 3 O 4 magnetite nanoparticles under optimum conditions has been found to be 10.26 mg of mercury ion per gram at pH 7 with the preconcentration factor of 500 (2 mL of elution for a 1000 mL sample volume). Standard solutions containing Hg 2+ in the concentration range of 0.2-200 ng mL À1 were examined by the proposed procedure and it was observed that calibration curve was linear in this range (R 2 ¼ 0.999). The special advantages of the proposed method are high enrichment factor, fast separation and low detection limits compared with other methods.

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