Electrochemical determination of nitazoxanide in environmental and pharmaceutical samples using a boron-doped diamond electrode

[Display omitted] •Electroanalytical method for nitazoxanide sensing in water and pharmaceutical samples.•Nitazoxanide determination in the absence of complex modification of electrode.•Good analytical performance ranging of 2.0–20.0 µmol L−1 of NTZ, LOD = 0.57 µmol L−1.•Selectivity even in the presence of other drugs also used in the COVID-19 pandemic.•All analysis were performed in small sample volumes for low waste generation. Consumption of Nitazoxanide (NTZ), a compound belonging to the class of nitrothiazoles, has increased due to its efficiency in treating viral gastroenteritis caused by rotavirus and norovirus “coronavirus disease”. Thus, developing a method capable of monitoring NTZ in wastewater and pharmaceutical formulations is relevant to human health control. However, most methods for NTZ determination are expensive and time-consuming. Hence, we present a fast, efficient, and low-waste method for NTZ monitoring in drugs and water samples using a boron-doped diamond electrode. A 3D-printed electrochemical cell with a capacity of 2 mL was used for all studies. Besides the simplicity of low waste generation, the method provided good analytical performance with a linear range of 2.0–20.0 µmol L−1 of NTZ, and a limit of detection (LOD) of 0.57 µmol L−1. Recovery percentages between 99 and 107 % were obtained to analyze spiked samples. In addition, we demonstrate that the LOD value can be significantly improved by 50 times after applying a pre-concentration step using solid-phase extraction. Therefore, we believe the described approach is a simple and efficient electrochemical method for monitoring NTZ levels in pharmaceutical and environmental samples without laborious sample preparation procedures. This is the first report to describe the use of BDD electrodes for NTZ monitoring and environmental sample analysis using an eco-friendly approach.