Dispersive solid phase micro-extraction of mercury(II) from environmental water and vegetable samples with ionic liquid modified graphene oxide nanoparticles

Abstract

A new dispersive solid phase micro-extraction (dispersive-SPME) method for separation and preconcentration of mercury(II) using ionic liquid modified magnetic reduced graphene oxide (IL-MrGO) nanoparticles, prior to the measurement by cold vapour atomic absorption spectrometry (CV-AAS) has been developed. The IL-MrGO composite was characterized by Brunauer-Emmett-Teller method (BET) for adsorption-desorption measurement, thermogravimetric analysis (TGA), powder X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The method is based on the sorption of mercury(II) on IL-MrGO nanoparticles due to electrostatic interaction and complex formation of ionic liquid part of IL-MrGO with mercury(II). The effect of experimental parameters for preconcentration of mercury(II), such as solution type, concentration and volume of the eluent, pH, time of the sorption and desorption, amount of the sorbent and coexisting ion concentration have been optimized. Under the optimized conditions, a linear response was obtained in the concentration range of 0.08-10 ng mL -1 with a determination coefficient of 0.9995. The limit of detection (LOD) of the method at a signal to noise ratio of 3 was 0.01 ng mL -1 . Intra-day and inter-day precisions were obtained equal to 3.4 and 4.5 %, respectively. The dispersive solid phase micro-extraction of mercury(II) on IL-MrGO nanoparticles coupled with cold vapour atomic absorption spectrometry was successfully used for extraction and determination of mercury(II) in water and vegetable samples.

Role of Ionic Liquids in Composites in Analytical Sample Preparation

“…Some studies also use sonication to improve the dispersion of the carbon material [59,60,[95][96][97]. It is interesting to mention that most of the studies use magnetic C-IL materials [61][62][63][64][65]77,96,[98][99][100][101][102][103][104][105][106]. In this case, the carbon materials are used as a support for the synthesis of MPs increasing the surface area of the material, and then, the magnetic carbon material is subsequently modified with the IL.…”

“…In this case, the carbon materials are used as a support for the synthesis of MPs increasing the surface area of the material, and then, the magnetic carbon material is subsequently modified with the IL. Regarding the type of carbonaceous materials used in the extraction schemes to prepare the composite, most of the studies use GO [58,62,64,65,95,[97][98][99][103][104][105][106][107][108][109][110][111][112][113], followed by G [57,63,100,102,114], while a few have reported the use of SWCNTs [96] and MWCNTs [59,60,77,101]. This may be due to the easy preparation of GO and G in comparison with the three-dimensional structures.…”

“…Amounts of the sorbents ranging between 2 and 80 mg have been employed in µ-dSPE and m-µ-dSPE methods, while the SPE cartridges were prepared using packing 200 mg of the composites. They have been mainly used for the determination of heavy metals [59,60,97,99,[103][104][105]112], pollutants [57,58,61,106,109,110,113], pesticides [63,95,101,102], drugs [96,98,107,108], hormones [64,114], microcystins [100], and phenolic acids [111], in a wide variety of samples, including water [60,61,63,95,[99][100][101]103,105,109,110,112,113], food [64,99,102,104,106,110,111,…”

A selective and easily recyclable dimer based on a calix[4]pyrrole derivative for the removal of mercury(ii) from water

“…Additionally they require large areas, maintenance and operational costs. In recent years a number of papers have been published on new approaches for removing mercury from water using functionalised silica sorbents based on mesoporous materials, 33 nanoparticles [34][35][36][37] and chelating agents. 38 Supramolecular chemistry 39 offers the possibility of producing highly selective receptors which can mimic some of the receptors present in living systems 40 for removing metal ions from water with the additional advantage that these can be easily recyclable, an important issue for the commercialisation of any technology, within this context calixpyrroles (products of the condensation of pyrrole and ketones in acid medium) possess properties of great interest, not the least as extracting agents for removing pollutants from the environment.…”

Preconcentration of ultra-traces of Cu(II) in water samples using SBA-15 sorbent modified with a thiocarbohydrazide ligand prior to determination by flame atomic absorption spectrometry

“…However, the heavy metals concentration levels in environmental samples are fairly low and preconcentration procedures are often needed. 8 Among the various methods, such as co--precipitation, 9 ion exchange, 10 liquid-liquid extraction (LLE), 11 reverse osmosis adsorption 12 and solid phase extraction (SPE), 13,14 solid phase extraction has attracted a considerable amount of interest for the preconcentration of toxic metal ions, [15][16][17] due to the higher efficiency and low use of pure organic solvents. This method is simple, efficient, selective, cost-effective and easy to automate without the need for emulsion, and it is safe concerning the reagents employed.…”