Selective Pre‐concentration and Solid Phase Extraction of Mercury(II) from Natural Water by Silica Gel‐loaded (E)‐N‐(1‐Thien‐2′‐ylethylidene)‐1,2‐phenylenediamine Phase

Abstract

Silica gel-loaded (E)-N-(1-thien-2'-ylethylidene)-1,2-phenylenediamine (TEPDA) phase was synthesized based on physical adsorption approaches. The stability of a chemically modified TEPDA especially in concentrated hydrochloric acid that was then used as a recycling and preconcentration reagent allowed the further uses of silica gel-loaded immobilized TEPDA phase. The application of this silica gel-loaded phase to sorption of a series of metal ions was performed by using different controlling factors such as the pH of the metal ion solution and the equilibration shaking time by the static technique. This difference was interpreted on the basis of selectivity incorporated in these sulfur containing silica gel-loaded TEPDA phases. Hg(II) was found to exhibit the highest affinity towards extraction by these silica gel-loaded TEPDA phases. The pronounced selectivity was also confirmed by the determined distribution coefficients (K d ) of all the metal ions, showing the highest value reported for mercury(II) extraction by the silica gel immobilized TEPDA phase. The potential applications of the silica gel immobilized TEPDA phase to selective extraction of mercury(II) from aqueous solution were successfully accomplished and preconcentration of low concentration of Hg(II) (30 pg•mL -1 ) from natural tap water with a preconcentration factor of 200 for Hg(II) off-line analysis was conducted by cold vapor atomic absorption analysis.

Extraction of Trace Cd(II) in Real Samples using Multi Walled Carbon Nanotubes Carboxylate

“…sorbent retained a homogenous distribution in the range of 156.0-10.0 nm. Fig.2.The formation of MWCNTs was followed by Raman Spectroscopy spectroscopy .the carbonyl vibration , while there are fingerprints at 160 cm -1 and 230 cm -1 due to the presence of hydroxyl species at the carbon nanotubes 23 .…”

“…Coprecipitation [11][12][13] , membrane filtration 14,15 , electrodeposition 16 , cloud point extraction 17 and solvent extraction [18][19][20][21] are the popular methods for the preconcentration and separation of the traces transition metal ions. Solid phase extraction (SPE) of trace metal ions is also an important preconcentration/separation technique 1,[22][23][24][25] .…”

Separation of Cr(III) from by Functionalized Graphene Oxide with Covalently Linked Porphyrin (GO–H2NP) Adsorbed on Surfactant Coated C18

“…Therefore there are numerous methods and techniques concerning chromium speciation and determination including liquid-liquid extraction after complex formation [3][4] ,solid-liquid extraction [5][6][7][8][9] , LC-AAS [10][11] ,FIA-AAS 38,39 , spectrophotometric 12,39 , ICP-AES 13 , and NAA 14 . However, some of these techniques are currently, time consuming and have elaborate sample preparation steps and low enrichment factors.…”

“…The method developed was simple, reliable, and precise for determining Cr in water. Also, the proposed method was free of interference compared to conventional procedures to determine Cr 17,21,[38][39] . The methode can be successfully applied to the separation and determination of Cr in binary mixtures.…”

Extraction of Trace Copper(II) in Water Samples using Ammonium Pyrrolidine Dithiocarbamate(APDC) Modified Carbon Nanotubes to Measurement by FAAS

“…Thus, the development of new methods for selective separation, concentration and determination of it in sub-micro levels in different industrial, medicinal and environmental samples is of continuing interest. The determination of copper is usually carried out by flame and graphite furnace atomic absorption spectrometry (AAS) 11,12 as well as spectrometric methods 13,14 . However, due to the presence of copper in medicinal and environmental samples at low levels, its separation from other elements presents and also the use of a preconcentration step prior to its determination is usually necessary.…”