Selective extraction and preconcentration of ultra-trace level of mercury ions in water and fish samples using Fe3O4-magnetite-nanoparticles functionalized by triazene compound prior to its determination by inductively coupled plasma-optical emission spectrometry

Abstract

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.

Atomic spectrometry update. Clinical and biological materials, foods and beverages

“…Reports of new procedures for more conventional preconcentration were also seen during the last year. Rofouei et al 39 added Fe 3 O 4 magnetite nanoparticles modied with 1-( p-acetylphenyl)-3-(o-ethoxyphenyl)triazene to samples to effect adsorption of Hg 2+ . The particles were recovered by application of a magnetic eld and the Hg 2+ eluted for measurement by ICP-AES.…”

“…Newly synthesized magnetite nanoparticles were used for a rapid extraction and preconcentration of iHg at sub-ppb concentrations from water and sh samples. 39 The magnetite nanoparticles, functionalised with 1-(p-acetylphenyl)-3-(o-ethoxyphenyl)triazene iHg-binding ligands, can be isolated from the sample with a magnetic eld. When coupled with ICP-AES, this extraction and system can deliver a preconcentration factor of 500 with an LOD of 0.04 ng mL À1 and an RSD of 2.09%.…”

Reversible magnetic mercury extraction from water

“…Recently, Pang et al 15 reported the synthesis of functionalised iron oxide nanoparticles which efficiently remove mercury(II) from water samples (380 mg Hg 2+ extracted per mol adsorbent) but selectivity in combination with other metals or recyclability of this scavenger material was not studied. On the other hand, Khani et al 14 have developed magnetite nanoparticles functionalised with triazene groups showing selectivity towards mercury in binary systems, which could be used in 2 cycles with an extraction capacity of 10.26 mg Hg 2+ per gram nanomaterial. Mandel et al have reported that thiol-modied magnetic microparticles are capable of extracting mercury(II) preferentially over other metal ions.…”

Determination of ultratraces of mercury species using separation with magnetic core-modified silver nanoparticles and electrothermal atomic absorption spectrometry

“…In this way, the maximum benet of the high preconcentration factors (PFs) that can be achieved by means of different microextraction approaches is obtained. [15][16][17][18][19] When used for SPE microextraction processes, these materials are easily separated by a magnet without the need for centrifugation. 8 In this respect, numerous adsorbents have been proposed for the separation of metals but, in most cases, their physical characteristics and the subsequent leaching of the analytes do not permit high PFs to be obtained.…”