Applications of Graphene and Its Derivatives in Chemical Analysis

In this review, the applications of graphene and its derivatives in the chemical analysis have been described. The properties of graphene materials which are essential for their use in chemical and biochemical analysis are characterized. The materials are used in sensors and biosensors, in electrochemistry, in chromatography and in the sample preparation techniques. Chemical and electrochemical sensors containing graphene materials are useful devices for detecting some chemical and biochemical compounds. Chromatographic columns for HPLC with graphene containing stationary phases may be used for separation of polar and nonpolar components of some specific mixtures. Graphene materials could be successfully employed during sample preparation for analysis with SPE, magnetic SPE, and SPME techniques. HighlightsThe review of the applications of graphene (G) and its derivatives, graphene oxide (GO) and reduced graphene oxide (rGO), in chemical and biochemical analysis is proposed.The electron donor-acceptor and proton donor-acceptor interactions for the graphene based materials - analytes systems and their impact on the analysis results are discussed, particularly:    i) in electrochemistry,ii) in chromatography,iii) in modern sample preparation techniquesiv) in sensors of different types.The essence of the thermal stability and the nomenclature of the graphene based materials in their different applications in chemical systems of different classes was discussed (and suggested).The benefits of using SPME fibers with immobilized graphene materials have been presented in detail.

Application of multivariate optimization procedures for preconcentration and determination of Au(III) and Pt(IV) in aqueous samples with graphene oxide by X-ray fluorescence spectrometry

A simple method was developed for the determination of Au(III) and Pt(IV) contents in aqueous samples after preconcentration. The method was based on the sorption of analytes as 2-amino-5-mercapto-1,3,4-thiadiazol complexes onto graphene oxide and subsequent direct determination by wavelength dispersive X-ray fluorescence (WDXRF). The optimization step was carried out using two-level full-factorial and Box-Behnken designs. The effects of four variables (pH, ligand mass, sonication time, and temperature) were studied by a full-factorial design to find significant variables and their interactions. Results of two-level full-factorial design for Au extraction showed that the factors: pH, ligand mass, temperature of sonication beside the interaction of pH-ligand mass, and interaction sonication temperature-ligand mass were significant. For Pt, the results revealed pH, ligand mass, sonication time, and interaction of pH-ligand mass were statistically significant. Box-Behnken matrix design was applied to determine the optimum level of significant parameters for extraction of two analytes simultaneously. The optimum values of the factors were pH 2.5, 0.9 mL ligand solution, 56 min sonication time and 15 °C temperature. The limits of detection (LOD) were found to be 8 ng mL(-1) for Au and 6 ng mL(-1) for Pt. The adsorption capacity for Au and Pt were 115 and 169 μg mg(-1), respectively. The relative standard deviation (RSD) was lower than 1.4 % (n = 5), and the extraction percentage was more than 95 % for both elements. The method was validated by determination of Au and Pt in spiked water samples and certified reference standard materials.

Speciation and determination of inorganic arsenic species in water and biological samples by ultrasound assisted-dispersive-micro-solid phase extraction on carboxylated nanoporous graphene coupled with flow injection-hydride generation atomic absorption spectrometry

In this paper, carboxylated nanoporous graphene as a nanoadsorbent was evaluated in two types of ultrasound assisted-dispersive micro-solid phase extraction for speciation of trace As(v) and As(iii) ions in natural water and human biological samples.