Navegando por Autor "Lima, Phabyanno Rodrigues"
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Item Boletim Técnico – Monitoramento de glifosato no Complexo Estuarino Lagunar Mundaú-Manguaba (CELMM) por cromatografia de íons com supressão química e detector de condutividade(Instituto Federal de Educação Ciência e Tecnologia de Alagoas, 2022-07-29) Novais, José Fábio Felix de; Lima, Phabyanno RodriguesNenhumItem Desenvolvimento de sensor eletroquímico baseado em eletrodos impressos de carbono, modificados com Ácido Polixanturênico para detecção da Afloxitina B1(Instituto Federal de Educação Ciência e Tecnologia de Alagoas, 2019-12-05) Silva, Jéssica da Conceição da; Lima, Phabyanno Rodrigues; http://lattes.cnpq.br/9334426018309756; Cavalcante, Sarah Kelly Melo; http://lattes.cnpq.br/0820477133147241; Silva, Jailson dos SantosIn the present work we describe the development of an electrode that uses xanturenic acid (AX) for the first time as an electrochemical probe, through a simple and efficient Aano-activated, nanomaterial modified carbon printed electrode immobilized with aptamers for the detection of aflotoxin. B1 (AFB1). The sensor surface was characterized by voltammetric techniques such as differential pulse voltammetry (VPD) and cyclic voltammetry (VC), which were used to study the behavior of modified electrodes, to optimize experimental parameters and obtain kinetic parameters. as a study of speed and pH. The electroactive species, quinone / hydroquinone, was electrogenerated in situ on the modified nanomaterials and AX electrode after cycles in the potential range between 0.5 and -1.0 vs. Ag at first sweep in 0.1 mol L-1 phosphate buffer (pH 5.5) with sweep rate of 50 mV s-1. After the activation process, the potential range around the redox quinone / hydroquinone pair was selected and the voltammograms were recorded at different speeds (5-20 mV s-1), then aptamer immobilization was performed, applied with the intention of to test the electrocatalytic activity for AFB1 oxidation. In addition, the electroactive species generated on the electrode surface showed inhibition against the immobilized aptamer when reacting with AFB1, causing a charge retention. Thus, from the results obtained the electrochemical aptensor developed showed a promising alternative to be applied in tests with real samples.Item Desenvolvimento de um potenciostato portátil de baixo custo e seu uso em análises ambientais(Instituto Federal de Educação Ciência e Tecnologia de Alagoas, 2023-09-18) Lucena, Charles Bronson Bezerra de; Lima, Phabyanno Rodrigues; http://lattes.cnpq.br/9334426018309756; Lopes, Cleylton Bezerra; http://lattes.cnpq.br/4000861323429729; Silva, Francisco de Assis dos Santos; http://lattes.cnpq.br/8842303844359230The planet's population has been growing consistently over the decades. The most recent pro- jections indicate that in the next ten years we will have an increase of 80 million people and that this number will only increase in the following decades. This fact will bring a series of challenges and among them we can mention the need to produce food for this large number of people without compromising the environment even further. Each year, the agricultural harvest in Brazil has been breaking records, in the same way that the use of agricultural pesticides is increasing in the same direction. If these substances are not used appropriately, they will quickly harm the environment and monitoring becomes increasingly necessary. This monitoring is car- ried out through chemical analysis. Raising awareness among new generations about problems related to environmental degradation is important and this can be done in chemistry classes. As is well known, carrying out practices in the laboratory makes learning easier and more effective. In this sense, carrying out practical classes requires essential equipment: a potentiostat. This equipment is expensive and its use is mostly restricted to research laboratories. This research sought to develop a potentiostat capable of carrying out electrochemical analyzes with the main characteristics being its low cost, ease of manufacture and portability where its focus is not on carrying out analyzes with great precision to be used in classes for the quantification of internal contaminants. -environmental stress. We searched the literature for projects that included some of these characteristics to promote adaptations and improvements with the aim of minimizing costs. The equipment developed was subjected to calibration using the electrical resistance method to verify its compliance with Ohm's law. It presented a difference of +/- 0.14% in rela- tion to a fictitious resistance compared to a difference of +/- 0.1% presented by a commercial potentiostat. Improvements in the future such as improving the software with the insertion of new electrochemical techniques, modifying the microcontroller (Arduino pro mini, or similar and developing another communication cable.Item Determinação de ácido ascórbico: um sensor eletroquímico à base de pasta de carbono com 4-nitroanilina adsorvida em silica gel modificada(Instituto Federal de Educação Ciência e Tecnologia de Alagoas, 2019-12-05) Santos, Monik Tamíres Silva; Cavalcante, Sarah Kelly Melo; http://lattes.cnpq.br/0820477133147241; Lima, Phabyanno Rodrigues; http://lattes.cnpq.br/9334426018309756; Cavalcante, Sarah Kelly Melo; http://lattes.cnpq.br/0820477133147241; Silva, Jailson dos SantosThe present work describes the development of a multiple wall carbon nanotube paste electrode (MWCNTPE) based on 4-nitroaniline (4NA) adsorbed onto silica gel modified with zirconium oxide (SZ) to detect ascorbic acid (AA). The sensing surface was characterized by Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM) and Infrared Spectroscopy (FTIR). The electroactive species, hydroxylamine / nitrous (R-NHOH / R-NO), was electrogenerated in situ from 4Nitroaniline after cycling in the potential range between 0.5 and -1.0 vs. Ag / AgCl in the first scan in 0.1 mol L-1 PBS buffer (pH 7.0) with a scanning rate of 0.02 Vs-1. The modified electrode showed efficient electrocatalytic activity against the oxidation of ascorbic acid in 0.3 V vs. Ag / AgCl. Electrochemical measurements including Cyclic Voltammetry (VC) and Chronoamperometry were used to study the behavior of the surface of the modified electrode used. These techniques were used to optimize the experimental parameters. Thus, under optimized conditions, the sensor presented a linear response range of 0.5 - 3.0 μmol.L-1, LD (0.15 μmol.L-1), LQ (0.48 μmol.L-1) and sensitivity of 7.60 (mA.L.mmol-1) adding to the sensor positive factors in sensitivity and selectivity. This sensor was applied for the amperometric determination of AA in food samples. The results were consistent with those obtained with the standard titration procedure.Item Monitoramento de glifosato no Complexo Estuarino Lagunar Mundaú-Manguaba (CELMM) por cromatografia de íons com supressão química e detector de condutividade(Instituto Federal de Educação Ciência e Tecnologia de Alagoas, 2022-07-29) Novais, José Fábio Felix de; Lima, Phabyanno Rodrigues; http://lattes.cnpq.br/9334426018309756; Lopes, Cleylton Bezerra; http://lattes.cnpq.br/4000861323429729; Lima, Sarah Kelly Melo Cavalcante Rodrigues; http://lattes.cnpq.br/0820477133147241The Estuarine Complex Lagunar Mundaú-Manguaba - CELMM has relevant cultural, gastronomic, social, economic and environmental importance for the cities that surround it. The main economic activity developed that encompasses its surroundings comes from the sugarcane agroindustry, responsible for the use of tons of pesticides every year in the monoculture of sugarcane. In the last 4 decades, the tributaries of the CELMM have been receiving inorganic contaminants (nutrients from fertilizers) from the sugarcane industry and agribusiness, through leaching caused by the hydrological cycle, feeding streams, rivers and channels that flow into its bed, acting as a vehicle transporter by agricultural flow of ions, with a tendency to modify the physical, chemical and biological characteristics of its ecosystem. However, for this reason, there is a need for detailed studies focusing on the determination of pesticides in the CELMM basin region. In this sense, among the various types of pesticides sold in Brazil, those products with a broad spectrum of action, the so-called non-selective, systemic and post-emergent, such as the herbicide glyphosate N-(phosphonomethyl) glycine, stand out. In this perspective, 8 samples were collected at 8 points of surface water up to 20 cm deep in the streams and channels of the agricultural region that flow into 4 municipalities that make up the CELMM, being collected in the period of the sugarcane harvest to determine the following ions of interest for public health by ion chromatography, such as glyphosate and other anions (fluoride, chloride, nitrite, bromide, nitrate, sulfate and phosphate) and cations (lithium, sodium, potassium, ammonium, magnesium, calcium). The municipalities in the state of Alagoas monitored were: Maceió/AL, Marechal Deodoro/AL, Pilar and Santa Luzia do Norte/AL. The analytical results did not show glyphosate concentrations above the limits of quantification (LQ) determined in the calibration curves of the monitored ions, which are (0.05 mg L-1), whereas other anions and cations that were quantified have concentrations below the Maximum Permissible Value (MPV) in accordance with current Brazilian legislation.