Synthesis, characterization and application of a novel mercapto- and amine-bifunctionalized silica for speciation/sorption of inorganic arsenic prior to inductively coupled plasma mass spectrometric determination

Abstract

a b s t r a c tA bifunctional sorbent, (NH 2 + SH)silica, containing both amine and mercapto functionalities was prepared by modification of silica gel with 3-(triethoxysilyl)propylamine and (3-mercaptopropyl)trimethoxysilane. In addition to the bifunctional sorbent, silica gel was modified individually with the functional mercapto-and amino-silanes, and the mono-functional sorbents, namely (SH)silica and (NH 2 )silica, were also mechanically mixed ((NH 2 )silica + (SH)silica) for the sake of comparison of sorption performances. It has been demonstrated that (SH)silica shows quantitative sorption only to As(III) at two pH values, 1.0 and 9.0, while (NH 2 )silica displays selectivity only towards As(V) at pH 3.0. On the other hand, the bifunctional (NH 2 + SH)silica possesses the efficient features of the two mono-functionalized sorbents; for example, it retains As(III) at a wider pH range, from 1.0 to at least 9.0 with the exception at pH 2.0, and it also shows quantitative sorption to As(V) at pH 3.0. This property gives the bifunctional (NH 2 + SH)silica a better flexibility in terms of sorption performance as a function of solution pH. The mechanically mixed (NH 2 )silica + (SH)silica exhibits a similar but less efficient sorption behavior compared to the bifunctional sorbent. Desorption of both As(III) and As(V) species can be realized using 0.5 M NaOH. The validity of the proposed method was checked through the analysis of a standard reference material and a good correlation was obtained between the certified (26.67 g L −1 ) and determined (27.53 ± 0.37 g L −1 ) values. Spike recovery tests realized with ultrapure water (93.0 ± 2.3%) and drinking water (86.9 ± 1.2%) also confirmed the applicability of the method.

Solid Phase Extraction to On-Line Preconcentrate Trace Cadmium Using Chemically Modified Nano-Carbon Black with 3-Mercaptopropyltrimethoxysilane

“…The effect of oxidation can be evaluated in Figure 1b, which shows clearly aggregation of particles most likely due to intramolecular forces as hydrogen bond ascribed to the functional groups hydroxyl, carbonyl and carboxyl on the surface. 38 On the other hand, the modification with 3-MPTMS of oxidized CB promoted a new disaggregation of particles although lower than CB, indicating the grafting of 3-MPTMS on the surface owing to the hydrophobic feature of silane agent.…”

Template Synthesis of Immobilized polysiloxane Diamine-Thiol tetraacetic acid Bi-Ligand system and its application for determination of metal ions

“…More recently bi-ligand thiol-amine polysiloxane ligand systems were firstly reported by El Nahhal and his research group in 1996 [23]. Further researches were developed by Yurity Zub in 2008 and Ahmet E. Eroglu in 2011 [27,28]. Previously we have reported two separate polysiloxane ligand systems, a polysiloxane immobilized amine-acetate and a thiol-acetate polysiloxane [29].…”

Speciation analysis of chromium in water samples through sequential combination of dispersive magnetic solid phase extraction using mesoporous amino-functionalized Fe3O4/SiO2 nanoparticles and cloud point extraction

“…In order to obtain information on particle size and morphology of materials TEM images were obtained [32], thus demonstrating the successful of synthesis herein adopted.…”