Jessica Scremin

Simultaneous Voltammetric Determination of Antihypertensive Drugs Amlodipine and Atenolol in Pharmaceuticals Using a Cathodically Pretreated Boron-Doped Diamond Electrode

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.

Electrochemical study of the antiplatelet agent ticlopidine and its voltammetric determination in pharmaceutical and urine samples using a boron-doped diamond electrode

In the present study, the electrochemical behavior of ticlopidine was investigated by cyclic voltammetry, square-wave voltammetry and differential pulse voltammetry using a cathodically pretreated boron-doped diamond electrode. Ticlopidine exhibited one well developed and irreversible oxidation peak suitable for analytical purposes at about 0.95 V (vs. Ag/AgCl 3.0 mol L−1 KCl) in BR buffer solution (pH 5.0). The electrode reaction of the analyte was found to be a diffusion-controlled process. At optimized differential pulse voltammetric parameters (modulation amplitude of 150 mV, scan rate of 10 mV s−1 and modulation time of 10 ms), the obtained analytical curve was linear for the ticlopidine concentration range of 3.9 to 38.4 μmol L−1 with a detection limit of 0.66 μmol L−1. The influence of possible interfering compounds was studied as well. The proposed method was applied with success in the determination of ticlopidine in pharmaceutical and urine samples with good accuracy and precision.

A simple square-wave voltammetric method for the determination of scopolamine in pharmaceuticals using a boron-doped diamond electrode

A simple procedure is described for the determination of scopolamine by square-wave voltammetry using a cathodically pretreated boron-doped diamond electrode. Cyclic voltammetry studies indicate that the oxidation of scopolamine is irreversible at a peak potential of 1.59 V (vs. Ag/AgCl (3.0 mol L-1 KCl)) in a 0.50 mol L–1 sulfuric acid solution. Under optimized conditions, the analytical curve obtained was linear (r = 0.9996) for the scopolamine concentration range of 1.0 to 110 µmol L–1, with a detection limit of 0.84 µmol L–1. The method was successfully applied to the determination of scopolamine in pharmaceutical formulations with minimum sample preparation.