Voltammetric determination of trimethoprim employing an electrode chemically modified with prussian blue film

Abstract

Biologically active drugs are a matter of environmental and public health concern even at smaller concentrations. For this reason, several investigators have pursued instrumental methods to determine these substances. Trimethoprim is an antibacterial agent that is after employed to treat infections in human and veterinary medicine. In the present study, we applied a glass carbon electrode chemically modified with iron (III) hexacyanoferrate (II) film (Prussian blue) and cyclic voltammetry to analyze trimethoprim. We obtained an analytical curve with a linear correlation coefficient (r) of 0.990, standard deviation (SD) of 0.027 μA, detection limit (based on the 3 SD/m ratio) of 16.2 nmol L–1, and a limit of quantification (based on the relationship 10 SD/m) of 54 nmol L–1.