An improved drop casting electrochemical strategy for furosemide quantification in natural waters exploiting chemically reduced graphene oxide on glassy carbon electrodes

• DOI: 10.1007/s00216-020-02845-9
• Publication Date: 2020-08-01T03:45:36Z
• Authors: Sancler C. Vascon...; Eduardo M. Rodrigues; Leonardo G. de Al...; Fábio G. Lepri; Wagner F. Pacheco; Felipe S. Semaan; Rafael M. Dornellas
• Keywords: Reproducibility of Results; Electrochemical Techniques; 02 engineering and technology; Carbon; 6. Clean water; Furosemide; Limit of Detection; Graphite; Spectrophotometry, Ultraviolet; Diuretics; 0210 nano-technology; Electrodes; Oxidation-Reduction; Chromatography, High Pressure Liquid; Water Pollutants, Chemical

This work exploits the applicability of a chemically reduced graphene oxide (CRGO) modification on the electrochemical response of a glassy carbon electrode (GCE) for the first-time sensitive determination of furosemide in natural waters. The batch injection analysis (BIA) is proposed as an analytical method, where CRGO-GCE is coupled to a BIA cell for amperometric measurements. Acetate buffer (0.1 μmol L-1, pH 5.2) was used as the background electrolyte. The modification provided an increase in sensitivity (0.024 μA/μmol L-1), low limit of detection (0.7 μmol L-1), RSD (< 4%), and broad linear range (1-600 μmol L-1). Recovery tests performed in two different concentration ranges resulted in values between 89 and 99%. Recovery tests were performed and compared with high-performance liquid chromatography (HPLC) with UV-Vis detection using Student's t test at a 95% significance level, and no significant differences were found, confirming the accuracy of the method. The developed method is proven faster (169 h-1) compared with the HPLC analysis (5 h-1), also comparable with other flow procedures hereby described, offering a low-cost strategy suitable to quantify an emerging pharmaceutical pollutant. Graphical abstract.