Determination of some trace elements in sea-water by atomic absorption spectrometry after concentration with modified silicas

Abstract

Silica gels modified with 3-aminopropyltriethoxysilane or 3-mercaptopropyltrimethoxysilane groups have been developed for the preconcentration of copper and cadmium prior to their determination by flame atomic absorption spectrometry. The surface areas of the modified silica gels were determined by the Brunauer-Emmett-Teller (BET) method to be 290 m2 g-l of the amino-modified silica and 410 m2 g-1 of the thiol-modified silica. Batch and column methods were used for the separation and concentration of copper and cadmium. These metals were quantitatively retained on both the modified gels in slightly acidic media. In the batch method, the effects of pH, shaking time and type of buffer on the adsorption of copper and cadmium were investigated. In the batch and column procedures both copper and cadmium adsorbed on the silicas were quantitatively recovered (relative standard deviation of 2-6%) using 2 mol dm-3 hydrochloric acid even in the presence of sodium chloride up to a concentration of 1 .O%.

The Solid Phase Extraction of Lead Using Silver Nanoparticles – Attached to Silica Gel Prior to its Determination by FAAS

“…On the other hand, as a supporting material, silica gel is especially of particular interest because it does not swell, has good mechanical strength and thermal stability as well as quite large surface area. Therefore, instead of direct use as a sorbent, it is rather modified commonly with inorganic and organofunctional groups to increase its interest towards the analytes [10][11][12][13][14][15][16].…”

RETRACTED: Cloud point extraction of palladium in water samples and alloy mixtures using new synthesized reagent with flame atomic absorption spectrometry (FAAS)

“…The cloud point phenomenon is reversible and when the temperature is falls bellow the CPT a single phase appear again. Several Preconcentration methods and separation techniques such as liquid-liquid extraction [16], co-precipitation [17], ion-exchange [18,19], sorption on the various adsorbents such as activated carbon [20], silica [21,22], polymeric resin [23][24][25][26], activated columns [27], Amberlite XAD resins [28] and other sorbents [29][30][31], cloud point extraction is a facile, rapid and versatile technique employed for preconcentration and analysis of pesticides, polychlorides and phenols [32,33]. The analytical application of the cloud point phenomenon extend the extraction of toxic organic compound, medical drugs, vitamins and oils to the extraction of metal chelates, with several detection techniques.…”

The Use of Water Soluble Polymers for the Pre-Concentration and Separation of Copper, Lead, and Chromium Prior to Their Determination by Graphite Furnace Atomic Absorption Spectrometry

“…For this purpose activated carbon, [1] silica [2] and numerous polymers with or without chelating groups [3][4][5] have been the most favored stationary phases used as collectors. For this purpose activated carbon, [1] silica [2] and numerous polymers with or without chelating groups [3][4][5] have been the most favored stationary phases used as collectors.…”