Mass spectrometry parameters optimization for the 46 multiclass pesticides determination in strawberries with gas chromatography ion-trap tandem mass spectrometry

Multiclass analysis method was optimized in order to analyze pesticides traces by gas chromatography with ion-trap and tandem mass spectrometry (GC-MS/MS). The influence of some analytical parameters on pesticide signal response was explored. Five ion trap mass spectrometry (IT-MS) operating parameters, including isolation time (IT), excitation voltage (EV), excitation time (ET),maximum excitation energy or “q” value (q), and isolationmass window (IMW) were numerically tested in order to maximize the instrument analytical signal response. For this, multiple linear regression was used in data analysis to evaluate the influence of the five parameters on the analytical response in the ion trap mass spectrometer and to predict its response. The assessment of the five parameters based on the regression equations substantially increased the sensitivity of IT-MS/MS in the MS/MS mode. The results obtained show that for most of the pesticides, these parameters have a strong influence on both signal response and detection limit.Using the optimized method, a multiclass pesticide analysis was performed for 46 pesticides in a strawberry matrix. Levels higher than the limit established for strawberries by the European Union were found in some samples.

Paroles de femmes : positionnement et stratégies de résistance

Nées des travaux des féministes américaines, les gender studies, faut-il le rappeler, se sont constituées aux Etats Unis dans les années quatre-vingts à partir des questionnements sur les rapports hommes / femmes au sein de la société. Depuis les années soixante-dix, la French Theory avait déjà joué un rôle très important dans le débat théorique américain avec les philosophes Gilles Deleuze, Jacques Derrida, Michel Foucault, Jean-François Lyotard… Remettant sans cesse en question le pouvoir, l’institution et la manière de penser, ils se sont distingués par la force de leur posture critique et par leur engagement. Aussi faut-il rappeler l’importance des travaux et des réflexions de femmes intellectuelles françaises, comme Hélène Cixous, Julia Kristeva, Luce Irigaray et tant d’autres pour les études du genre.

Development and biological evaluation of API-ILs based on anti-bacterial and anti-fungal drugs

In recent years Ionic Liquids (ILs) are being applied in life sciences. ILs are being produce with active pharmaceutical drugs (API) as they can reduce polymorphism and drug solubility problems [1] Also ILs are being applied as a drug delivery device in innovative therapies What is appealing in ILs is the ILs building up platform, the counter-ion can be carefully chosen in order to avoid undesirable side effects or to give innovative therapies in which two active ions are paired. This work shows ILs based on ampicillin (an anti-bacterial agent) and ILs based on Amphotericin B. Also we show studies that indicate that ILs based on Ampicillin could reverse resistance in some bacteria. The ILs produced in this work were synthetized by the neutralization method described in Ferraz et. al. [2] Ampicillin anion was combined with the following organic cations 1-ethyl-3-methylimidazolium, [EMIM]; 1-hydroxy-ethyl-3-methylimidazolium, [C2OHMIM]; choline, [cholin]; tetraethylammonium, [TEA]; cetylpyridinium, [C16pyr] and trihexyltetradecylphosphonium, [P6,6,6,14]. Amphotericin B was combined with [C16pyr], [cholin] and 1-metohyethyl-3-methylimidazolium, [C3OMIM]. The ILs-APIs based on ampicillin[2] were tested against sensitive Gram-negative bacteria Escherichia coli ATCC 25922 and Klebsiella pneumonia (clinical isolated), as well as on Gram positive Staphylococcus Aureus ATCC 25923, Staphylococcus epidermidis and Enterococcus faecalis. The arising resistance developed by bacteria to antibiotics is a serious public health threat and needs new and urgent measures. We study the bacterial activity of these compounds against a panel of resistant bacteria (clinical isolated strains): E. coli CTX M9, E. coli TEM CTX M9, E. coli TEM1, E. coli CTX M2, E. coli AmpC Mox2. In this work we demonstrate that is possible to produce ILs from anti-bacterial and anti-fungal compounds. We show here that the new ILs can reverse the bacteria resistance. With the careful choice of the organic cation, it is possible to create important biological and physic-chemical properties. This work also shows that the ion-pair is fundamental in ampicillin mechanism of action.

Produção de biodiesel via catálise heterogénea básica

Mestrado em Engenharia Química. Ramo Tecnologias de Protecção Ambiental.

Melhoria do processo produtivo na indústria do mobiliário

Com o aumento da concorrência, a crise económica que atravessamos e com a conquista de novos mercados no horizonte, surge a necessidade de responder a essas situações com uma melhor prestação do sistema produtivo no sentido de reduzir tempos de produção e de baixar os custos dos mesmos, podendo assim dar uma resposta mais rápida e competitiva às expectativas dos clientes. Esta dissertação tem como objectivo analisar todo o sistema produtivo da empresa, desenvolvendo um estudo adequado ao sistema actual de fabrico de mobiliário, propondo melhorias que proporcionem uma melhor organização e uma redução dos custos de fabrico. Fez-se também um levantamento do sistema de planeamento existente, detectando pontos de melhoria que, para além de um maior controlo e organização, permitem, em alguns aspectos, a melhoria do sistema produtivo. Foi apresentada uma proposta de um processo de reengenharia aplicado ao sistema produtivo, tendo em vista implementar as medidas de melhoria, indo ao encontro das situações identificadas, tornando assim o sistema produtivo mais eficiente.

Analysis of PCBs in soils and sediments by microwave-assisted extraction, headspace-SPME and high resolution gas chromatography with ion-trap tandem mass spectrometry

A procedure for the determination of seven indicator PCBs in soils and sediments using microwave-assisted extraction (MAE) and headspace solid-phase microextraction (HS-SPME) prior to GC-MS/MS is described. Optimization of the HS-SPME was carried out for the most important parameters such as extraction time, sample volume and temperature. The adopted methodology has reduced consumption of organic solvents and analysis runtime. Under the optimized conditions, the method detection limit ranged from 0.6 to 1 ng/g when 5 g of sample was extracted, the precision on real samples ranged from 4 to 21% and the recovery from 69 to 104%. The proposed method, which included the analysis of a certified reference material in its validation procedure, can be extended to several other PCBs and used in the monitoring of soil or sediments for the presence of PCBs.

Selective recognition in potentiometric transduction of amoxicillin by molecularly imprinted materials

The indiscriminate use of antibiotics in foodproducing animals has received increasing attention as a contributory factor in the international emergence of antibiotic- resistant bacteria (Woodward in Pesticide, veterinary and other residues in food, CRC Press, Boca Raton, 2004). Numerous analytical methods for quantifying antibacterial residues in edible animal products have been developed over years (Woodward in Pesticide, veterinary and other residues in food, CRC Press, Boca Raton, 2004; Botsoglou and Fletouris in Handbook of food analysis, residues and other food component analysis, Marcel Dekker, Ghent, 2004). Being Amoxicillin (AMOX) one of those critical veterinary drugs, efforts have been made to develop simple and expeditious methods for its control in food samples. In literature, only one AMOX-selective electrode has been reported so far. In that work, phosphotungstate:amoxycillinium ion exchanger was used as electroactive material (Shoukry et al. in Electroanalysis 6:914–917, 1994). Designing new materials based on molecularly imprinted polymers (MIPs) which are complementary to the size and charge of AMOX could lead to very selective interactions, thus enhancing the selectivity of the sensing unit. AMOXselective electrodes used imprinted polymers as electroactive materials having AMOX as target molecule to design a biomimetic imprinted cavity. Poly(vinyl chloride), sensors of methacrylic acid displayed Nernstian slopes (60.7 mV/decade) and low detection limits (2.9×10-5 mol/L). The potentiometric responses were not affected by pH within 4–5 and showed good selectivity. The electrodes were applied successfully to the analysis of real samples.

À la quete du salut dans la peste et dans en attendant, Godot

Soit La peste soit En attendant Godot traitent de l‘absurde de la condition humaine et de la quête du salut. La vie se présente sans avenir et comme un enchaînement de scènes pénibles qui se ressemblent. L‘humanité veut désespérément atteindre le bonheur et préserver sa dignité, mais, malgré tout effort, rien ne change : c‘est la terrible stabilité du monde. Presque tous les personnages manquent d‘identité. Ce sont des prisonniers de leur propre existence; des guignols manipulés arbitrairement par le destin; des victimes de la gratuité de la grâce divine. Les personnages, le temps, l‘espace, le langage, les silences, tout y sert à exprimer l‘absurde de la condition humaine. Dans ces deux oeuvres, l‘air est plein de cris de révolte. Les plaintes deviennent le langage naturel de l‘humanité souffrante, parce que, après tout, ni Godot ni le salut n‘arrivent jamais.

Approche autofictionnelle de l'homosexualite dans l'oeuvre romanesque de Conrad Detrez. Allusion, latence et chastete

Conrad Detrez does not write ―gay novels‖ as literary critique sees this expression nowadays. However, through self-fiction, Detrez´s novels present an allusive, latent and prudish approach of this topic, which is essential in the author and narrator‘s obsessions

Selective recognition in potentiometric transduction of amoxicillin by molecularly imprinted materials

The indiscriminate use of antibiotics in food-producing animals has received increasing attention as a contributory factor in the international emergence of antibiotic-resistant bacteria (Woodward in Pesticide, veterinary and other residues in food, CRC Press, Boca Raton, 2004). Numerous analytical methods for quantifying antibacterial residues in edible animal products have been developed over years (Woodward in Pesticide, veterinary and other residues in food, CRC Press, Boca Raton, 2004; Botsoglou and Fletouris in Handbook of food analysis, residues and other food component analysis, Marcel Dekker, Ghent, 2004). Being Amoxicillin (AMOX) one of those critical veterinary drugs, efforts have been made to develop simple and expeditious methods for its control in food samples. In literature, only one AMOX-selective electrode has been reported so far. In that work, phosphotungstate:amoxycillinium ion exchanger was used as electroactive material (Shoukry et al. in Electroanalysis 6:914–917, 1994). Designing new materials based on molecularly imprinted polymers (MIPs) which are complementary to the size and charge of AMOX could lead to very selective interactions, thus enhancing the selectivity of the sensing unit. AMOX-selective electrodes used imprinted polymers as electroactive materials having AMOX as target molecule to design a biomimetic imprinted cavity. Poly(vinyl chloride), sensors of methacrylic acid displayed Nernstian slopes (60.7 mV/decade) and low detection limits (2.9 × 10−5 mol/L). The potentiometric responses were not affected by pH within 4–5 and showed good selectivity. The electrodes were applied successfully to the analysis of real samples.