The use of square wave adsorptive stripping voltammetry (SWAdSV) in conjunction with a cyclic renewable silver amalgam film electrode (Hg(Ag)FE) for the analytical determination of ambazone in urine samples and pharmaceutical formulations is described. A single reduction peak in Britton-Robinson buffer at pH 4.0 was detected at about −1.4 V versus Ag/AgCl. Mechanistic studies have shown that the compound can act as an electrocatalyst. The method was validated. The analytical curve was linear in the concentration range from 1.0×10−9 to 1.0×10−7 mol L−1. The detection and quantification limits were found to be 3.0×10−10 mol L−1 and 1.0×10−9 mol L−1, respectively. The proposed method was successfully applied to ambazone determination in real samples.
Electrochemical oxidation of methylthiomethyleneisoquinolinium chloride (MTMIQ), the first alkylthiomethyl substituted ammonium salt, which is fully miscible with water has been investigated by voltammetric (SWV) method using glassy carbon electrode. On the electrode, MTMIQ undergoes oxidation at the potential near Ep = 0.07V (vs. Ag/AgCl/3 M KCl). The influence of the pH of buffers, amplitude, frequency, step potential on the received signal was studied. The best results were obtained with a citrate buffer at a pH of 5. The oxidation peak current used for MTMIQ voltammetric determination was in the range of 2–8×10−5 mol L−1, LOD = 3.7×10−6, LOQ = 1.2×10−5. The product of the oxidation was accumulated at the working electrode and was investigated by spectroscopic method. Mechanistic pathways of the oxidation have been proposed. [...]
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