Alexander Castro

INSTITUT DE CHIMIE ORGANIQUE ET ANALYTIQUE - ICOA

The process of convectively self-assembling particles in films suffers from low reproducibility due to its high dependency on particle concentration, as well as a variety of interactions and physical parameters. Inhomogeneities in flow rates and instabilities at the air-liquid interface are mostly responsible for reproducibility issues. These probl...

The process of convectively self‑assembling particles in films suffers from low reproducibility due to its high dependency on particle concentration, as well as a variety of interactions and physical parameters. Inhomogeneities in flow rates and instabilities at the air‑liquid interface are mostly responsible for reproducibility issues. These probl...

A novel hybrid plasmonic platform based on the synergetic combination of a molecularly imprinted polymer (MIP) thin film with Au nanoparticles (NPs) assemblies, noted as [email protected], was developed for surface-enhanced Raman scattering (SERS) spectroscopy recognition of polycyclic aromatic hydrocarbons (PAHs). While the MIP trapped the PAH clo...

Different ionic liquids (ILs) were studied in this work as mobile phase modifiers for the separation and determination of Hg2+, methylmercury (CH3Hg+) and ethylmercury (C2H5Hg+) species by reversed-phase high-performance liquid chromatography coupled to UV-cold vapor atomic fluorescence spectrometry (RP-HPLC-UV-CV-AFS). Several parameters influenci...

Nanomaterials and ionic liquids (ILs) have very attractive properties for improved analytical preconcentration methods. Thus, ILs have been used as excellent tools to functionalize nanomaterials, giving them specific chemical properties for higher selectivity, extraction efficiency and extended re-utilization in preconcentration. Moreover, incorpor...

In the present article a new approach for the synthesis of magnetic polymeric ionic liquid nanocomposites based on the Radziszewski reaction is presented. The Radziszewski reaction is a simple and successful procedure to obtain imidazolium-containing polymers under mild conditions and consists of the reaction between diamine compounds, glyoxal and...

A flow injection system based on a modified polytetrafluoroethylene (PTFE) knotted reactor (KR) was developed for arsenite [As(III)] and arsenate [As(V)] species preconcentration and determination by electrothermal atomic absorption spectrometry (ETAAS). Activated carbon (AC) was immobilized on the inner walls of a PTFE KR by a thermal treatment. A...

The capabilities of several phosphonium-ionic liquids (PILs) to form ion-pairs with a complex obtained by reaction of arsenate species with molybdate were evaluated. Phosphonium-ILs containing the tetradecyl(trihexyl)phosphonium cation but different anions (dicyanamide and decanoate) and tributyl(methyl)phosphonium methylsulphate IL were studied. T...

Several phosphonium-ionic liquids (ILs) were studied to assay their application as ion-pairing agents. Basically, a selective microextraction procedure is proposed based on the formation of As(V)- molibdate complex followed by ion pair reaction with ILs. The ion pair was extracted into a few μL of solvent and As was determined by direct injection...

A preliminary approach based on statics and dynamics studies involving removal of Arsenic (As) -as As(V)- from aqueous solutions is presented in this work. Raw and trihexyltetradecyl-phosphonium chloride ionic liquid-impregnated polymeric resins were evaluated for removal of As(V). Measurements of As(V) were made by Electrothermal Atomic Absorption...

Ionic liquids (ILs) are novel solvents that display a number of unique properties, such as negligible vapor pressure, thermal stability (even at high temperatures), favorable viscosity, and miscibility with water and organic solvents. These properties make them attractive alternatives to environmentally unfriendly solvents that produce volatile org...

Tin oxide (IV) or cassiterite obtained by the controlled precipitation method was characterized by different physical and chemical techniques such as TEM, surface area, XRD and RTP for the determination of the morphology, particle size distribution and reduction temperature of the system and then, a pure catalyst and doped with tin (Sn) and nickel...