Publications by authors named "Jhonys Machado Freitas"

A simple, accurate, and environmentally friendly method for the simultaneous determination of the analog endocrine disruptors bisphenol S (BPS) and bisphenol A (BPA) was developed and validated. The determination was performed by square-wave voltammetry using a cathodically pretreated boron-doped diamond (BDD) as the working electrode, with 0.1 mol L HSO as the supporting electrolyte.

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Boron-doped diamond (BDD) electrodes present several notable properties, such as the largest potential window of all electrode materials (especially in anodic potentials), low background and capacitive currents, reduced fouling compared to other electrodes, mechanical robustness, and good stability over time. On the other hand, flow-based systems are known as well-established approaches to minimize reagent consumption and waste generation and with good compromise between sample throughput and analytical performance (mechanization of chemical assays). This review focuses on the use of BDD electrodes for electrochemical detection in flow systems, such as flow injection analysis (FIA), batch injection analysis (BIA), high performance liquid chromatography (HPLC), and capillary electrophoresis (CE).

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In this work, a batch-injection analysis system with square-wave voltammetric (BIA-SWV) detection was applied for the first time to the simultaneous determination of inorganic (zinc) and organic (naphazoline) species. Both compounds were detected in a single run (70 injections h(-1)) with a small injection volume (∼100 µL). The calibration curves exhibited linear response range between 3.

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In this work, the possibility of simultaneous determination of three compounds with a single-injection step using batch injection analysis with multiple pulse amperometric detection (BIA-MPA) is demonstrated for the first time. A sequence of three potential pulses (+1.25 V, +1.

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