SEQUENTIAL CYCLIC-SQUARE-WAVE VOLTAMMETRIC DETERMINATION OF SULFANILAMIDE AND CIPROFLOXACIN IN ENVIRONMENT WATER SAMPLES USING A 3D-PRINTED ELECTROCHEMICAL DEVICE

Sulfanilamide (SAD) and ciprofloxacin (CIP) are widespread antibiotics, and their indiscriminate use, coupled with improper disposal contribute to the increase in the contamination levels of aquatic ecosystems [1]. Herein, we propose a 3D-printed carbon black/polylactic acid (CB/PLA) electrochemically activated electrode [2] to determine CIP and SAD concurrently by cyclic square-wave voltammetry (C-SWV) approach, which is a variant of the square-wave voltammetry (SWV) technique based on performing sequential scans in the anodic and cathodic directions [3]. Firstly, SWV measurements were conducted exploiting the oxidation processes Ox1CIP and Ox1SAD (+1.3 V and +1.1 V vs. Ag|AgCl|KCl(sat.)). However, the lack of selectivity was verified in the analysis of water samples. Then, the C-SWV strategy was used in the determination of Ox1CIP in the forward scan and Red1SAD (+0.5 V vs. Ag|AgCl|KCl(sat.)) in the reverse scan. Under selected C-SWV conditions, linear ranges from 4.96 to 40.61 µmol L-1 (r = 0.9977) for Ox1CIP and 1.99 to 10.78 µmol L-1 (r = 0.9989) for Red1SAD were obtained. The limits of detection for SAD and CIP were 0.2 and 0.6 µmol L-1, respectively, with sensitivity improving by 25% for CIP and 60% for SAD using this protocol, which also enhances selectivity by allowing the analytes to be distinguished at different potentials. Analysis of water samples (no dilution step) yielded good recovery values from 85 to 112%.

References

[1] Q. Wang, Q. Xue, Chin. Chem. Lett. 32, 609–619 (2021);[2] E.M. Richter, D.P. Rocha, Anal. Chem. 91, 12844–12851, (2019); [3] M. Buleandra, D.E. Popa, Microchem. J. 160, 10562, (2021