Encontrados 47 documentos, a visualizar página 1 de 5
Tyrosinase biosensor based on a glassy carbon electrode modified with multi-wal...
Vicentini, Fernando Campanhã; Janegitz, Bruno C.; Brett, Christopher M. A.; Fatibello-Filho, OrlandoA glassy carbon electrode modified with functionalized multi-walled carbon nanotubes (MWCNT), 1-butyl-3-methylimidazolium chloride (ionic liquid = IL) and tyrosinase (Tyr) within a dihexadecylphosphate (DHP) film for the development of a biosensor is proposed. MWCNT, IL and Tyr were efficiently immobilized in the film using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) as crossli...
Utilização de eletrodos sólidos de amálgama para a determinação analítica de co...
Souza,Djenaine de; Melo,Luisa Célia; Correia,Adriana Nunes; Lima-Neto,Pedro de; Fatibello-Filho,Orlando; Mascaro,Lucia HelenaThis review reports the use of solid amalgam electrodes in the electroanalytical determination of organic and inorganic compounds. The different types of amalgam electrodes are presented, and attention is paid to solid amalgam electrode, and here is presented details about the pre-treatment for activation and renovation and also possible modifications in its surface. The wide potential range, higher signal-to-n...
A Low-Cost Portable Microcontrolled Nephelometer for Potassium Determination
Santos,Vagner B. dos; Guerreiro,Thiago B.; Suarez,Willian T.; Faria,Ronaldo C.; Fatibello-Filho,OrlandoA low-cost portable microcontrolled nephelometer for the determination of potassium in coconut water and energy beverages is proposed. The nephelometer was constructed using two LEDs (light emitting diodes) as radiation sources at 465 nm and 880 nm, two photodiodes as photodetectors, and a peripheral interface controller (PIC) to acquisition and processing data of the nephelometer. The nephelometer was used to ...
Removal of copper(II) from sugar-cane spirits employing chitosan
Janegitz,Bruno C.; Oliveira,Andrea; Gomes,Marcos S.; Sartori,Elen R.; Pereira-Filho,Edenir R.; Fatibello-Filho,OrlandoA method employing chitosan as complexant agent in the removal of copper(II) ions generally present in the Brazilian cachaça samples is herein proposed. The efficiency of this method is attributed to its high capacity of metal cations adsorption, mainly due to presence of hydroxyl and amine groups that can serve as chelating sites. The removal of copper(II) ions from this alcoholic beverage was efficient employ...
A multicommuted flow procedure for the determination of total and free choleste...
Leite,Oldair D; Vieira,Heberth J; Fatibello-Filho,Orlando; Rocha,Fábio R. PA multicommuted flow-based procedure with detection by chemiluminescence for the determination of total and free cholesterol without changes in the flow manifold is proposed. Cholesterol esterase and cholesterol oxidase were both immobilized on glass beads via glutaraldehyde/(3-aminopropyl)-triethoxysilane and mini-columns containing the enzymes were used for online sample treatment. Cholesterol esters were cle...
Spectrophotometric flow injection system for determination of Zn2+ in ophthalmi...
Fatibello-Filho,Orlando; Vieira,Heberth JulianoA spectrophotometric flow injection method for the determination of Zn(II) in ophthalmic formulations was developed. In this work, Zn(II) ion was complexed with Alizarin red S in borate buffer solution (pH 9.0) and the chromophore produced was monitored at 520 nm. The analytical curve was linear in the Zn(II) concentration range from 6.05 x 10-6 to 1.50 x 10-4 mol L-1 with a detection limit of 3.60 x 10-6 mol L...
Determinação turbidimétrica em fluxo de cloridrato de fluoxetina em formulações...
Suarez,Willian Toito; Sartori,Elen Romão; Batista,Érica Ferreira; Fatibello-Filho,OrlandoA simple, accurate and precise flow-injection turbidimetric procedure for the determination of fluoxetine hydrochloride in pharmaceutical formulations is reported. The procedure is based on the precipitation of chloride of fluoxetine hydrochloride with silver nitrate solution and the yielded insoluble AgCl(s) was monitored at 420 nm. The analytical curve was linear in the fluoxetine hydrochloride concentration ...
Determinação de paracetamol pela inibição da reação quimiluminescente do lumino...
Oliveira,Geiser G.; Janegitz,Bruno C.; Batistão,Marina B.; Salami,Fernanda H.; Fatibello-Filho,Orlando; Leite,Oldair D.A flow injection chemiluminescence method for the determination of paracetamol in pharmaceutical formulations is described. It is based on the consumption of the sodium hypochlorite by paracetamol and decreases of the analytical signal. The analytical curve was linear in the paracetamol concentration range from 5.0 x 10-6 to 5.0 x 10-5 mol L-1, with a detection limit of 1.8 x 10-6 mol L-1. The RSDs were 2.0 and...
Determinação condutométrica de cloridrato de metformina em formulações farmacêu...
Sartori,Elen Romão; Suarez,Willian Toito; Fatibello-Filho,OrlandoA simple, precise, rapid and low-cost conductometric titration method for the determination of metformin hydrochloride (MET) in pharmaceuticals using silver nitrate as titrant is proposed. The method was based on the chemical reaction between the chloride of metformin hydrochloride molecule and Ag(I) ions, yielding the precipitate AgCl(s). The method was applied for MET determination in three pharmaceuticals an...
Determinação espectrofotométrica em fluxo de cloro em água usando célula de lon...
Salami,Fernanda Helena; Bonifácio,Viviane Gomes; Fatibello-Filho,Orlando; Marcolino-Jr,Luiz HumbertoA multicommuted method for determination of chlorine in water samples using a 100-cm cell was developed. In this method, orto-Tolidine reacts with chlorine and the product was monitored at 438 nm. The analytical curve for chlorine was linear in concentration range from 1.34x10-6 to 2.01x10-5 mol L-1 with a detection limit of 9.40x10-8 mol L-1. A sampling rate of 45 h-1and a RSD of 1.0 % (n = 15) were obtained. ...
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