Lúcio Angnes

Learn More
A novel unmediated hydrogen peroxide biosensor based on the incorporation of fibrous tissue of coconut fruit in carbon paste matrix is presented. Cyclic voltammetry and amperometry were utilized to characterize the main electrochemical parameters and the performance of this new biosensor under different preparation and operation conditions. The resulting(More)
The development of a new methodology for the construction of very efficient flow cells for mercury detection by potentiometric stripping analysis, employing the thin gold layer of recordable CDs as working electrode is reported. This new source of electrodes (CDtrodes) show very attractive performance, similar to that obtained with commercial gold(More)
This paper describes the separation and quantification of salbutamol in pharmaceutical products (salbutamol syrups) by capillary electrophoresis (CE) with contactless conductivity detection (C(4)D). The system was studied by micellar electrokinetic capillary chromatography (MEKC) and free solution capillary electrophoresis (FSCE), being the latter chosen in(More)
This work describes an efficient, fast, and reliable analytical methodology for mercury determination in urine samples using stripping chronopotentiometry at gold film electrodes. The samples were sonicated in the presence of concentrated HC1 and H2O2 for 15 min in order to disrupt the organic ligands and release the mercury. Thirty samples can be treated(More)
An automated method for dn/dc determination using a surface plasmon resonance instrument in tandem with a flow injection gradient system (FIG-SPR) is proposed. dn/dc determinations of small molecule and biomolecule, surfactant, polymer, and biopolymer solutions with precision around 1-2% and good accuracy were performed using the new method. dn/dc(More)
This paper proposes a new, fast and precise method to analyze isoniazid based on the electrochemical oxidation of the analyte at a glassy carbon electrode in 0.1M NaOH. The quantification was performed utilizing amperometry associated with batch injection analysis (BIA) technique. Fast sequential analysis (60 determinations h(-1)) in an unusually wide(More)
Flow injection analysis (FIA) with amperometric detection was employed for the quantification of N-acetylcysteine (NAC) in pharmaceutical formulations, utilizing an ordinary pyrolytic graphite (OPG) electrode modified with cobalt phthalocyanine (CoPc). Cyclic voltammetry was used in preliminary studies to establish the best conditions for NAC analysis. In(More)
A new composite material constituted by mu-{5,10,15,20-tetra(4-pyridyl)porphyrinato cobalt(iii)}-tetrakis-{chloro-bis-(2,2'-bipyridine)ruthenium(ii)} complex (or CoTRP) and cobalt oxide, exhibiting high stability and sensitivity for the quantification of hydrogen peroxide, was obtained by the electrochemical polymerization of the tetraruthenated cobalt(More)
Flow 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 5x10(-7) to 3.5x10(-4) mol L(-1), in 0.1 mol L(-1) sulfuric acid(More)
A simple, rapid and precise amperometric method has been developed for quantification of ascorbic acid (AA) in pharmaceutical formulations using flow-injection analysis (FIA). A slice of recordable compact disc (CD) modified by electrodeposition of platinum was employed as the working electrode. The proposed flow system allows determinations in the 1 mumol(More)