Rafael Lucena

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In this paper, a novel extraction approach based on the use of a polymeric membrane as the extraction medium is described. For this aim, an original unit which allows the magnetic stirring of the membrane during the extraction process has been designed, optimized, and practically evaluated. On one hand, the main variables affecting the extraction process(More)
Dispersive liquid-liquid microextraction (DLLME) has been proved to be a powerful tool for the rapid sample treatment of liquid samples providing at the same time high enrichment factors and extraction recoveries. A new, simple and easy to handle one step in-syringe set-up for DLLME is presented and critically discussed in this paper. The novel approach(More)
Cks is an evolutionarily conserved protein that regulates cyclin-dependent kinase (CDK) activity. Clarifying the underlying mechanisms and cellular contexts of Cks function is critical because Cks is essential for proper cell growth, and its overexpression has been linked to cancer. We observe that budding-yeast Cks associates with select phosphorylated(More)
In this article, effervescence assisted dispersive liquid-liquid microextraction with extractant removal by magnetic nanoparticles is presented for the first time. The extraction technique makes use of a mixture of 1-octanol and bare Fe3O4 magnetic nanoparticles (MNPs) in acetic acid. This mixture is injected into the sample, which is previously fortified(More)
A simple and rapid method for the determination of seven phenothiazines derivatives (chlorpromazine, promethazine, levomepromazine, prochlorperazine, trifluoperazine, fluphenazine and thioridazine) in human urine samples is presented. The analytes are extracted from the sample in 50 microL of the ionic liquid 1-butyl-3-methyl-imidazolium hexafluorophosphate(More)
Stir fabric phase sorptive extraction (SFPSE), which integrates sol-gel hybrid organic-inorganic coated fabric phase sorptive extraction media with a magnetic stirring mechanism, is presented for the first time. Two flexible fabric substrates, cellulose and polyester were used as the host matrix for three different sorbents e.g., sol-gel(More)
A stir membrane liquid phase microextraction procedure working under the three-phase mode is proposed for the first time for the determination of six anti-inflammatory drugs in human urine. The target compounds are isolated and preconcentrated using a special device that integrates the extractant and the stirring element. An alkaline aqueous solution is(More)
In this article, a novel extraction approach, called stir frit microextraction (SFME), is presented. The new approach combines the extractive capability of a commercial polyethylene frit (20 μm of pore size) with the stirring in the same device. The proposed extraction procedure allows the determination of benzene, toluene, ethylbenzene, xylene isomers and(More)
The paper presents a general overview of the use of nanoparticles to perform sample preparation. In this way the main uses of nanoparticles to carry out solid phase extraction, solid phase microextraction, liquid-liquid extraction and filtration techniques are described for a wide range of nanoparticles including carbon nanoparticles, metallic, silica and(More)