Magnetic Graphene Oxide Composite for the Microextraction and Determination of Benzophenones in Water Samples

Abstract

Magnetite nanoparticles (Fe3O4) functionalized with graphene oxide (GO) have been synthesized through a silanization process of the magnetic nanoparticles with tetraethyl orthosilicate and (3-aminopropyl)triethoxysilane and further coupling of GO. The synthesized nanomaterials have been characterized by several techniques, such as transmission electron microscopy (TEM), and infrared and Raman spectroscopy, which enabled the evaluation of the different steps of the functionalization process. The hybrid nanomaterial has been employed for the extraction of five benzophenones (benzophenone-1, benzophenone-3, 4-hydroxybenzophenone, benzophenone-6 and benzophenone-8) in aqueous samples by dispersive micro-solid phase extraction, combining the magnetic properties of magnetite nanoparticles with the excellent sorption capacity of graphene oxide via hydrophobic interactions with the analytes. The subsequent separation and quantification of the analytes was performed by liquid chromatography with tandem mass spectrometric detection, achieving limits of detection (LODs) in the range 2.5 to 8.2 μg·L−1, with relative standard deviations ranging from 1.3–9.8% and relative recovering in the range 86 to 105%. Positive swimming pool water samples analysed following the developed method revealed the presence of benzophenones in from 14.3 to 39 μg·L−1.

Tailoring the Surface of Natural Graphite with Functional Metal Oxides via Facile Crystallization for Lithium-Ion Batteries

“…There are two characteristic Raman peaks at 1360 and 1560 cm –1 , which are associated with the D band (disordered structure) and G band (graphitic structure) of NG, respectively. Unlike pristine NG, after a facile-crystallization process, additional Raman bands corresponding to the crystalline MoO 2 vibration (350, 454, and 483 cm –1 ), the Mo–O vibration (582 and 732 cm –1 ), and the Fe 3 O 4 A 1g mode (670 cm –1 ) were evident, as shown in Figure d. , …”

“…33 As can be seen in the magnified pattern of c-MoO 2 -NG (Figure 3b ) were evident, as shown in Figure 3d. 34,35 The surface chemistry and chemical state of a-MeO x -NG and c-MeO-NG before and after the facile-crystallization process were further investigated by XPS. The XPS profiles were carefully deconvoluted based on a binding energy of 284.5 eV for C 1s excitation.…”

Single-Walled (Magnetic) Carbon Nanotubes in a Pectin Matrix in the Design of an Allantoin Delivery System

“…The group of peaks observed at approximately 213, 270, 387, 486, and 585 cm –1 belongs to the stretching vibrations of Fe and O in hematite (Fe 2 O 3 ). The presence of Fe 2 O 3 can be associated with the oxidation of magnetite to hematite owing to the high-power laser used during measurement. − The peak at approximately 142 cm –1 is called the RBM mode and is the characteristic peak of the SWCNT structure. , …”

Benzophenones in the Environment: Occurrence, Fate and Sample Preparation in the Analysis

“…The low extraction time (¬ 15–20 min) is a great alternative to the tedious SPE procedures. The material could be reused up to four times without the loss of sensitivity [ 77 ]. The downside of this method in comparison to the others mentioned is the high LOD (2500–8200 ng/L).…”