Screen-Printed Electrodes for the Voltammetric Sensing of Benzotriazoles in Water.

Benzotriazoles (BZTs) are high production volume industrial chemicals that are used in various applications such as corrosion inhibitors, antifreeze agents, and UV radiation stabilizers. Given their potential ecotoxicological implications for different ecosystems and in human health, as well as their poor biodegradability, they are of increasing concern. In this study, a new voltammetric method using commercial screen-printed electrodes (SPEs) has been developed for the sensing of BZTs in water samples to help in their environmental monitoring. To this end, different types of SPEs based on carbon nanoallotropes and copper were tested under several experimental conditions to determine the two BZTs most frequently detected in the environment: 1H-benzotriazole (BZT) and 5-methyl-1H-benzotriazole (Me-BZT, tolyltriazole) as model compounds for BZTs. Carbon nanofibers electrodes exhibited the best performance, allowing detection limits as low as 0.4 mg L-1 for both BZTs, with repeatability and reproducibility of ca. 5%. The applicability of the method was tested through the determination of BZT in spiked drinking water samples, suggesting its suitability for the sensing of samples heavily polluted with BZTs.

Synthesis and physicochemical characterization of pyrrolidinium based surfactants.

Three new pyrrolidinium based surfactants were synthesized and characterized as pure aggregate components and in mixtures with 1,2-dimyristoyl-sn-glycero-3-phosphocholine to understand how the molecular structure of the cationic amphiphile and its mole percentage might affect the physicochemical properties of the resulting aggregates. The thermotropic behavior of the mixed liposomes was investigated by differential scanning calorimetry on multilamellar vesicles, whereas their size and surface potential were investigated on large unilamellar vesicles by dynamic laser light scattering and fluorescence experiments, respectively. The presence of either methoxy or hydroxy groups in the positions 3 and 4 of the pyrrolidinium ring as well as the presence of a second alkyl chain on pyrrolidinium nitrogen, controls the aggregates features.