Graphene oxide functionalized with L-asparagine applied to crystal violet dye removal from water and wastewater.

The efficiency of graphene oxide functionalized with L-asparagine (GO@L-Asn) as adsorbent for crystal violet (CV) dye removal from water and wastewater was investigated. The surface and textural properties of this new nanomaterial were characterized by pH at point of zero charge, Fourier-transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, and Brunauer-Emmet-Teller technique. The main experimental variables involved in dye adsorption process were evaluated and optimized.

Novel bionanomaterial based on Spirulina maxima algae and graphene oxide for lead microextraction and determination in water and infant beverages.

A new hybrid bionanomaterial composed of graphene oxide (GO) and Spirulina maxima (SM) algae was synthesized and applied to develop a preconcentration method based on the dispersive micro-solid phase extraction (D-μ-SPE) technique for the determination of Pb in water and infant beverages. In this work, Pb(II) was extracted with 3 mg of the hybrid bionanomaterial (GO@SM) followed by a back-extraction step using 500 µL of 0.6 mol L HCl.

Hybrid biomaterials to preconcentrate and determine toxic metals and metalloids: a review.

Toxic elements represent a serious threat to the environment and cause harmful effects on different environmental components, even at trace levels. These toxic elements are often difficult to detect through the typical instrumentation of an analytical laboratory because they are found at very low concentrations in matrices such as food and water. Therefore, preconcentration plays a fundamental role since it allows the effects of the matrix to be minimized, thus reaching lower detection limits and greater sensitivity of detection techniques.

Elemental Speciation Analysis in Environmental Studies: Latest Trends and Ecological Impact.

Speciation analysis is a key aspect of modern analytical chemistry, as the toxicity, environmental mobility, and bioavailability of elemental analytes are known to depend strongly on an element's chemical species. Henceforth, great efforts have been made in recent years to develop methods that allow not only the determination of elements as a whole, but also each of its separate species. Environmental analytical chemistry has not ignored this trend, and this review aims to summarize the latest methods and techniques developed with this purpose.

Ultra-sensitive Sb speciation analysis in water samples by magnetic ionic liquid dispersive liquid-liquid microextraction and multivariate optimization.

Efficient separation and preconcentration of inorganic Sb species in different water samples were performed in this work by a novel dispersive liquid-liquid microextraction (DLLME) method based on the application of a magnetic ionic liquid (MIL) and electrothermal atomic absorption spectroscopy (ETAAS) detection. The Sb(iii) species was selectively extracted by complexation with ammonium diethyldithiophosphate (DDTP) and 45 μL of the MIL trihexyl(tetradecyl)phosphonium tetrachloroferrate ([P6,6,6,14]FeCl4) as extractant. Subsequently, a magnetic rod was applied for phase separation, introducing it directly into the sample solution, and the MIL phase was then diluted in chloroform.

Determination of As in honey samples by magnetic ionic liquid-based dispersive liquid-liquid microextraction and electrothermal atomic absorption spectrometry.

A dispersive liquid-liquid microextraction (DLLME) method was developed based on the application of a magnetic ionic liquid (MIL) used as extractant phase for trace As determination in honey samples by electrothermal atomic absorption spectrometry (ETAAS). The procedure was simple, efficient and did not require a centrifugation stage. The As(III) species was preconcentrated by chelation with ammonium diethyldithiophosphate under acidic conditions at 3 mol L HCl, followed by the extraction of the chelated analyte with the MIL trihexyl(tetradecyl)phosphonium tetrachloroferrate (III) ([P]FeCl) and acetonitrile as dispersant.

Magnetic ionic liquid-based dispersive liquid-liquid microextraction technique for preconcentration and ultra-trace determination of Cd in honey.

A simple, highly efficient, batch, and centrifuge-less dispersive liquid-liquid microextraction method based on a magnetic ionic liquid (MIL-DLLME) and electrothermal atomic absorption spectrometry (ETAAS) detection was developed for ultra-trace Cd determination in honey. Initially, Cd(II) was chelated with ammonium diethyldithiophosphate (DDTP) at pH 0.5 followed by its extraction with the MIL trihexyl(tetradecyl)phosphonium tetrachloroferrate(III) ([P]FeCl) and acetonitrile as dispersant.

Ionic liquid-assisted separation and determination of selenium species in food and beverage samples by liquid chromatography coupled to hydride generation atomic fluorescence spectrometry.

Different ionic liquids (ILs) were assayed as mobile phase modifiers for the separation and determination of selenite [Se(IV)], selenate [Se(VI)], selenomethionine (SeMet) and Se-methylselenocysteine (SeMeSeCys) by reversed-phase high-performance liquid chromatography coupled to hydride generation atomic fluorescence spectrometry (RP-HPLC-HG-AFS). The use of several ILs: 1-butyl-3-methylimidazolium chloride, 1-hexyl-3-methylimidazolium chloride ([Cmim]Cl), 1-octyl-3-methylimidazolium chloride, 1-dodecyl-3-methylimidazolium bromide, 1-hexadecyl-3-methylimidazolium bromide and tributyl(methyl)phosphonium methylsulphate was evaluated. Also, the effect of pH, buffer type and IL concentration on the separation of Se species was studied.

A comparative evaluation of different ionic liquids for arsenic species separation and determination in wine varietals by liquid chromatography - hydride generation atomic fluorescence spectrometry.

The application of different ionic liquids (ILs) as modifiers for chromatographic separation and determination of arsenite [As(III)], arsenate [As(V)], dimethylarsonic acid (DMA) and monomethylarsonic acid (MMA) species in wine samples, by reversed-phase high performance liquid chromatography coupled to hydride generation atomic fluorescence spectrometry detection (RP-HPLC-HG-AFS) was studied in this work. Several factors influencing the chromatographic separation of the As species, such as pH of the mobile phase, buffer solution concentration, buffer type, IL concentration and length of alkyl groups in ILs were evaluated. The complete separation of As species was achieved using a C18 column in isocratic mode with a mobile phase composed of 0.