A novel miniaturized electroanalytical device integrated with gas extraction for the voltammetric determination of sulfite in beverages

• Published in: Analytica chimica acta Vol. 1185; p. 339067
• Main Authors: Araújo, Diele A.G., Oliveira, Ana C.M., Pradela-Filho, Lauro A., Takeuchi, Regina M., Santos, André L.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-11-2021
• Subjects: Copper electrode; Food analysis; Head-space; Miniaturization; Square wave voltammetry; Head-space; Square wave voltammetry; Miniaturization; Food analysis; Copper electrode
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2021.339067

Voltammetry and amperometry are inexpensive and high-performance analytical techniques. However, their lack of selectivity limits their use in complex matrices such as biological, environmental, and food samples. Therefore, voltammetric and amperometric analyses of these samples usually require time-consuming and laborious sample pretreatments. In this study, we present a simple and cost-effective approach to fabricate a miniaturized electrochemical cell that can be easily coupled to a head space-like gas extraction procedure in such a way the sample pretreatment and voltammetric detection are performed in a single step. As a proof of concept, we have used the proposed system to quantify sulfite in beverage samples after its conversion to SO2(g). Despite the simplicity and low cost of the proposed system, it provided good analytical performance and a limit of detection of 4.0 μmol L−1 was achieved after only 10 min of extraction. The proposed system is quite versatile since it can be applied to quantify any volatile electroactive species. Also, the proposed system provides a unique way to assess real-time extraction curves, which are essential to study and optimize new gas extraction procedures. Therefore, the approach described in this study could contribute to both applied and fundamental Analytical Chemistry.
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•A miniaturized electrochemical device was fabricated with alternative materials.•Gas extraction of sulfite and its voltammetric detection in a single step.•Gas extraction can be studied in real-time with a high temporal resolution.•Integrated sample pretreatment and detection improves selectivity and detectability.•Analytical performance was competitive with more sophisticated and complex devices.