Synthesis of aminopropyl triethoxysilane-functionalized silica and its application in speciation studies of vanadium(IV) and vanadium(V)

Abstract

a b s t r a c tA solid phase extraction sorbent, aminopropyl triethoxysilane-functionalized silica was prepared and used for vanadium speciation prior to inductively coupled plasma mass spectrometric determination. The necessary sorption parameters such as sorption pH, reaction temperature, sorbent amount and sample volume were optimized. The sorption for V(V) and V(IV) under the optimized conditions was 98% (±1) and was lower than 10%, respectively. The sorption process was investigated both from a kinetic perspective and also in terms of Freundlich, Dubinin-Radushkevich and Langmuir isotherm models to characterize the uptake of vanadate ion by the functionalized silica. Desorption from the sorbent was realized with 0.5 mol L −1 thiourea prepared in 0.2 mol L −1 HCl. Among the possible interfering species tested, Te(IV), Se(IV), Se(VI) and Fe(III) showed interference effects with V(V) signal. The validity of the method was first checked via spike recovery experiments with four different types of water; namely ultra pure, bottled drinking, tap, and sea water for different concentrations of V(V). The percent recovery values changed between 87 and 108 for all water types. The accuracy of the proposed methodology was also checked by analyzing a standard reference material (NIST, SRM 1643e) and a good agreement was found between the determined and the certified value. The proposed methodology has also been shown to be applicable for the separate sorption of V(V) in the absence/presence of V(IV) and for the sorption of both V(IV) and V(V) in waters. The amount of V(IV) can then be determined from the difference.

Synthesized of Sporopollenin-Immobilized Schiff Bases and Their Vanadium(IV) Sorption Studies

“…4 oxidation states as vanadyl cation, VO 2? , in reducing media and is stable in acidic solution below pH 2 [6]. However, it is known that vanadium exists in different hydrolyzed forms depending upon its concentration and the pH of the system [1].…”

“…Vanadium is known as an essential trace element for plants and animals. Although vanadium is important for biological system at low concentrations, it is toxic at high concentrations [6]. Vanadium has an electronic configuration of [Ar]3d 3 4s 2 and can exist in eight oxidation states ranging from -3 to ?5, but with the exception of -2.…”

“…Only the three highest, ?3, ?4 and ?5, are important in biological systems. Under ordinary conditions, the ?4 and ?5 oxidation states are the most stable [6,7]. The ?4 oxidation state, which is generally the most stable one for vanadium, is best represented by the vanadyl ion, VO 2?, which is stable in aqueous solution and under complexation with a wide range of ligands.…”

In-situ preparation of poly(ether imide)/amino functionalized silica mixed matrix membranes for application in enzyme separation

“…The amino functionalized hollow nanospheres were efficient adsorbents for CO 2 . APTES-functionalized silica was prepared for vanadium speciation by Erdem [32]. The amino functionalized titanium dioxide/silica nano hybrid material was prepared with APTES, TEOS and tetraethyl orthotitanate (TEOT), and the dyes adsorption of this material increased with the increases of number of amino groups [33].…”

Novel ultrasonic‐assisted deep eutectic solvent‐based dispersive liquid–liquid microextraction for determination of vanadium in food samples by electrothermal atomic absorption spectrometry: A multivariate study

“…At trace level it has a less toxic character as compared to lead, cadmium and mercury, but it also possesses useful biochemical functions, such as anti‐carcinogenic and insulin‐like characteristics . It is an important element for living beings . Vanadium pollution in the environment has been mostly related to industrial activities, particularly burning of coal and vanadium‐rich oils .…”