The simultaneous voltammetric determination of antihypertensive drugs amlodipine besylate (AML) and atenolol (ATN) using a cathodically pretreated boron-doped diamond electrode (CP-BDDE) is reported for the first time. The anodic peak potentials of AML and ATN at a CP-BDDE were found to be 0.727 and 1.32 V (vs. Ag/AgCl (3.0 mol L-1 KCl)) in phosphate buffer (pH 7.0), respectively, by cyclic voltammetry. It was observed that the CP-BDDE possesses improved performance for the simultaneous determination of AML and ATN when compared to other carbon-based electrodes in these conditions. Using square-wave voltammetric technique, the obtained analytical curves were linear in the concentration range from 2.9-33 µmol L-1 for AML and 9.8-190 µmol L-1 for ATN, with limits of detection of 0.17 and 0.22 µmol L-1, respectively. The proposed method was successfully applied to the simultaneous determination of AML and ATN in pharmaceutical samples.

A 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 employing either in column and batch system. The analysis were carried out employing the flame atomic absorption spectrometry and the remaining copper(II) concentrations in the treated cachaça were lower than LOD of FAAS technique.

Neste trabalho descreve-se a determinação do ácido acetilsalicílico (ASA) em formulações farmacêuticas empregando voltametria de onda quadrada (SWV) e um eletrodo de diamante dopado com boro (BDD). Neste método, ASA é determinado diretamente em solução de H2SO4 0,01 mol L-1, sem a necessidade da hidrólise alcalina. Foi obtido um único pico de oxidação no potencial de 1,97 V vs. Ag/AgCl (KCl 3,0 mol L-1) com características de uma reação irreversível. A curva analítica obtida é linear na faixa de concentração ASA de 2,50 × 10-6 -1,05 × 10-4 mol L-1, com um limite de detecção de 2,0 µmol L-1. O desvio padrão relativo foi menor que 1,4% para uma solução de ASA 45 µmol L-1 (n = 10). O método proposto foi aplicado com sucesso para a determinação de ASA em várias formulações farmacêuticas e os resultados obtidos foram concordantes com um método oficial da Farmacopéia Britânica, a um nível de confiança de 95%.

In this paper the determination of acetylsalicylic acid (ASA) in pharmaceutical formulations using square-wave voltammetry (SWV) and a boron-doped diamond electrode (BDD) is described. By this proposed method, ASA is directly determined in a 0.01 mol L-1 H2SO4 solution without the need of a previous time-consuming alkaline hydrolysis step. A single oxidation peak at a potential of 1.97 V vs. Ag/AgCl (3.0 mol L-1 KCl) with the characteristics of an irreversible reaction was obtained. The obtained analytical curve is linear in the ASA concentration range 2.50 × 10-6-1.05 × 10-4 mol L-1, with a detection limit of 2.0 µmol L-1. The obtained relative standard deviation was smaller than 1.4% for a 45 µmol L-1 ASA solution (n = 10). The proposed method was applied with success in the determination of ASA in several pharmaceutical formulations; the obtained results were in close agreement, at a 95% confidence level, with those obtained using an official method of the British Pharmacopoeia.