Navegando por Palavras-chave "Samples"

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    Determination of levetiracetam in human plasma by dispersive liquid-liquid microextraction followed by gas chromatography-mass spectrometry
    (Univ Sao Paulo, Inst Psiquiatria, 2016) Steinhorst Alcantara, Greyce Kelly; Calixto, Leandro Augusto [UNIFESP]; Beraldo de Moraes, Luiz Alberto; Costa Queiroz, Regina Helena; Moraes de Oliveira, Anderson Rodrigo; de Gaitani, Cristiane Masetto
    Levetiracetam (LEV) is an antiepileptic drug that is clinically effective in generalized and partial epilepsy syndromes. The use of this drug has been increasing in clinical practice and intra- or -interindividual variability has been exhibited for special population. For this reason, bioanalytical methods are required for drug monitoring in biological matrices. So this work presents a dispersive liquid-liquid microextraction method followed by gas chromatography-mass spectrometry (DLLME-GC-MS) for LEV quantification in human plasma. However, due to the matrix complexity a previous purification step is required. Unlike other pretreatment techniques presented in the literature, for the first time, a procedure employing ultrafiltration tubes Amicon (R) (10 kDa porous size) without organic solvent consumption was developed. GC-MS analyses were carried out using a linear temperature program, capillary fused silica column, and helium as the carrier gas. DLLME optimized parameters were type and volume of extraction and dispersing solvents, salt addition, and vortex agitation time. Under chosen parameters (extraction solvent: chloroform, 130 mu L
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    Development of modified electrodes based on self assembled films of polypirrole and carbon nanotubes composites for pesticides monitoring
    (Univ Estadual Campinas, Inst Estudos Linguagem, 2016) Araujo, Gabriela Martins de [UNIFESP]; Polacci, Luis Antonio [UNIFESP]; Mazzo, Tatiana Martelli [UNIFESP]; Codognoto, Lucia [UNIFESP]; Simões, Fabio Ruiz [UNIFESP]
    In this work polypyrrole (PPy) and its respective composite with functionalized multiwalled carbon nanotubes (PPy-MWCNT) was obtained by the chemical polymerization of the monomer pyrrole (PPy) in aqueous solution by the dropwise addition of a solution of ammonium persulfate (PSA). The obtained PPy as well as its composite (PPy-MWCNT) were used to prepare two self-assembled films (SA) by the immersion of ITO blades (Inidium Tin Oxide) into PPy and PPy-MWCNT dispersions with alternated immersions into Polystyrene sulfonate (PSS) dispersion, thus resulting in a bilayer. The SA films were produced with ten bilayers (alternated layers of PPy or its composite). The obtained films were characterized by Fourrier Transformed Infrared Spectroscopy (FTIR), UV-Visible analysis, voltammetric analyses (square wave and cyclic voltammetry) and Scanning Electron Microscopy (SEM). The SA films were evaluated to determine the chlorothalonil pesticide which is commonly used as anti-fouling agent in marine environments. The SWV results showed a reduction peak at around -0.8 to 1.2 V (according to pH). It was also observed a synergic effect of the composite film (PPy-MWCNT/PSS) to determine the chlorothalonil by increase of the peak currents.