Encontrados 13 documentos, a visualizar página 1 de 2
Flow injection analysis using carbon film resistor electrodes for amperometric ...
Felix, Fabiana S.; Brett, Christopher M.A.; Angnes, LúcioFlow injection analysis (FIA) using a carbon film sensor for amperometric detection was explored for ambroxol analysis in pharmaceutical formulations. The specially designed flow cell designed in the lab generated sharp and reproducible current peaks, with a wide linear dynamic range from 5 × 10-7 to 3.5 × 10-4 mol L-1, in 0.1 mol L-1 sulfuric acid electrolyte, as well as high sensitivity, 0.110 A mol-1 L cm-2 ...
Avaliação da composição química de águas do Sistema Guarapiranga: estudo de cas...
Richter,Eduardo M.; Fornaro,Adalgiza; Lago,Claudimir L. do; Angnes,LúcioThe supply of drinking water in the Metropolitan Area of São Paulo City has been a great and serious challenge in the latest years. This work demonstrates the viability of the evaluation of the degree of contamination of the water reservoirs using analytical procedures, which allow the analysis of several compounds at relatively low cost: stripping square wave voltammetry (SSWV) and capillary zone electrophores...
Ultrasound-assisted treatment of coconut water samples for potentiometric strip...
Munoz,Rodrigo A. A.; Kolbe,Matias; Siloto,Rita C.; Oliveira,Pedro V.; Angnes,LucioThis work describes the application of potentiometric stripping analysis (PSA) at mercury film electrodes for zinc determination in coconut water. A sample ultrasound-assisted treatment was developed and optimised for the total zinc determination by PSA. One milliliter of sample was treated with 2 mL of 1:1 (v/v) concentrated HCl and H2O2 (30% m/v) mixture in closed (4 mL) vessels under sonication (in ultrasoni...
Carbon film resistor electrode for amperometric determination of acetaminophen ...
Felix, Fabiana S.; Brett, Christopher M.A.; Angnes, LúcioFlow injection analysis (FIA) with amperometric detection was employed for acetaminophen quantification in pharmaceutical formulations using a carbon film resistor electrode. This sensor exhibited sharp and reproducible current peaks for acetaminophen without chemical modification of its surface. A wide linear working range (8.0 × 10-7 to 5.0 × 10-4 mol L-1) in phosphate buffer solution as well as high sensitiv...
Uso de frascos de polipropileno descartáveis no pré-tratamento de amostras de á...
Richter,Eduardo M.; Lago,Claudimir L. do; Angnes,LúcioIn this work a simple and versatile procedure is described for treating water samples using small polypropylene (PP) vials (4 mL) for determining heavy metals by square wave voltammetry (SWV). This procedure involves treatment with nitric acid (0.2 mol L-1) and boiling in a water-bath (~ 100 ºC). This process is completed after one hour and allows the pretreatment of several samples simultaneously. The accuracy...
Determination of anions, cations, and sugars in coconut water by capillary elec...
Richter,Eduardo M.; Jesus,Dosil P. de; Muñoz,Rodrigo A. A.; Lago,Claudimir L. do; Angnes,LúcioThis work presents the determination of several analytes in coconut water by using capillary electrophoresis with contactless conductivity detection (CCD). It was analyzed 5 different samples: two unprocessed (natural) coconut water and three processed (commercial) ones. The samples were injected without pretreatment and only a simple dilution was necessary. The technique was applied to quantify 12 analytes: ch...
Multímetro interfaceado de baixo custo para aquisição de dados
Richter,Eduardo M.; Rocha,Fábio R. P.; Angnes,LúcioA digital multimeter (~U$ 240.00 on the national market) connected to a microcomputer by a RS-232 serial interface is proposed for data acquisition in equipment with analog output. Data are measured at the rate of 2 points per second and stored in text files by the software that accompanies the device, running in a Windows environment. The performance of the multimeter was verified by monitoring the transient s...
Determination of inorganic ions in ethanol fuel by capillary electrophoresis
Munoz,Rodrigo A. A.; Richter,Eduardo M.; Jesus,Dosil P. de; Lago,Claudimir L. do; Angnes,LúcioThe control of the content of inorganic ions in vehicular fuels plays an important role in the engine maintenance. A novel and versatile methodology to carry out rapid analysis of ions in ethanol is presented. Capillary electrophoresis was used to quantify cations (sodium, potassium, calcium, magnesium, and ammonium) and anions (sulfate, chloride, and nitrate). The injection of the sample directly in the capill...
Aplicações eletroanalíticas com eletrodos de prata confeccionados a partir de C...
Richter,Eduardo M.; Jesus,Dosil P. de; Neves,Carlos A.; Lago,Claudimir L. do; Angnes,LúcioThis paper presents a new way for the construction of silver electrodes utilizing recordable CDs. The new electrodes were explored for the quantification of chloride (by potentiometry/FIA), cyanide (by amperometry/FIA) and for lead analysis (by square wave voltammetry). For the flowing measurements, a digital multimeter, connected to a microcomputer (via RS 232 interface) was used to collect directly the potent...
Propulsor pneumático versátil e isento de pulsação para sistemas de análise em ...
Matos,Renato C.; Gutz,Ivano G. R.; Angnes,Lúcio; Fontenele,Rinaldo S.; Pedrotti,Jairo J.Aquarium air pumps are proposed and evaluated as pneumatic liquid propulsion devices for flow injection and continuos flow analysis (FIA and CFA) systems. This kind of pump is widely available at a very low cost and it can sustain a pressure around of 4 psi (0.28 bar) indefinitely. By applying this air pressure onto a solution contained in a reservoir flask, it is possible to reach flow rates of up to 12.5 mL m...
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