Preconcentration and separation of copper(II), cadmium(II) and chromium(III) in a syringe filled with 3-aminopropyltriethoxysilane supported on silica gel

Abstract

In this study, a syringe was filled with silica gel loaded with 3-aminopropyltriethoxysilane, for the separation and preconcentration of copper, cadmium and chromium prior to their determination by graphite furnace atomic absorption spectrometry (GFAAS) in seawater. For this purpose, a syringe was filled with 0.5 g of modified silica gel and the sample solution was drawn into the syringe and ejected back again. The analyte elements were quantitatively retained at pH 5. Then, the elements sorbed by the silica gel were eluted with 2.0 M of HCl and determined by GFAAS. At optimum conditions, the recovery of Cu, Cd and Cr were 96-98%. Detection limits (3delta) were 6.6, 7.5 and 6.0 micro g L(-1) for Cu, Cd and Cr, respectively. The elements could be concentrated by drawing and discharging several portions of sample successively but eluting only once. Cu, Cd and Cr added to a seawater sample were quantitatively recovered (>95%) in the range of the 95% confidence level. The method proposed in this paper was compared with a column technique. Optimum experimental conditions, reproducibility, precision and recoveries of both techniques are the same, but the syringe technique is much faster, easier and more practical than the column technique. It is a portable system and allows one to make the sorption process in the source of sample. In addition, the risk of contamination is less than in the column technique.

Determination of Copper by Flame Atomic Absorption Spectrometry after Preconcentration with Activated Carbon Impregnated with a New Schiff Base

“…This preconcentration factor of the method by using HPPS was superior to those previously reported. 20,24 The limit of detection (LOD) of the method for the determination was studied under the optimal conditions. The LOD based on 3σ of the blank is 2.26 µg per 1000 mL.…”

“…37 The LOD values of previous methods were higher than those of our work, thus better LOD has been achieved with modified AC using HPPS. [23][24][25][26] The reproducibility of the proposed method for the extraction and determination of 50 µg copper from 50 mL of water was also studied. The results obtained on 10 replicate measurements revealed a CV of 1.5%.…”

“…Detection of copper ions with spectrophotometer is cheap, but interference from some ions such as Zn(II) and Fe(III) limited the procedure. Tokman et al 24 used 3-amino-propyltriethoxysilane supported on silica gel as preconcentrator for Cu(II). For this purpose, a syringe filled with modified silica gel was used.…”

A Practical Application of Solid-phase Extraction Using a Syringe Filled with Sorbent for the Determination of Lead and Cadmium in Water

“…This procedure was handy, fast and convenient. [6][7][8][9][10][11][12][13] The amine groups are one of the most efficient functional groups for the removal of heavy metal ions, 14,15 and various adsorbents with amine functional groups have been developed from natural biopolymers, e.g. chitosan, which contains amine groups in its backbone, 16 or from synthetic polymers that are subsequently immobilized with the amine groups.…”

Synthesis and Application of Amberlite XAD-2 Functionalized with Dithizone for Field Preconcentration and Separation of Trace Cadmium in Seawater

“…The couplings of flow injection (FI) sample preconcentration systems with conventional flame atomic absorption spectrometry (FAAS) have been carried out for trace metal determinations in complex diluted samples, including a minicolumn containing a chelating resin [2][3][4][5] or a solid sorbent. [6][7][8] In these methods, on-line minicolumn preconcentration systems using chelating resins are simpler and less time consuming than other options, allowing "in situ" sample preconcentration.…”