*2.3. Electrochemical Methods*

The measurement of the current, charge, and potential is utilized in electrochemical techniques to characterize an analyte's chemical reactivity and detect the concentration. The basic electrochemical signals that serve as analytical signals constitute current, charge, and potential [62]. These techniques include cyclic voltammetry, chronoamperometry, electro-chemical impedance spectroscopy, and potentiometry [63]. In comparison to separation and spectral methods, electrochemical methods offer practical advantages such as operation simplicity, satisfactory sensitivity, a wide linear concentration range, low instrument cost, miniaturization capability, suitability for real-time detection, and less sensitivity to matrix effects [34,64]. Due to advances in electronics and computer sciences, the electroanalysis of pharmaceutically active substances is actively involved in new study fields of various methodologies. Due to their great sensitivity and selectivity, many innovative electroanalytical techniques have been effectively employed for trace analyses of essential pharmaceutically active substances [65]. The electrochemical analysis of active pharmaceuticals is based on redox processes that occur via electron transfer channels [66]. Electrochemical methods have been used for the analysis of antibiotics such as clarithromycin and azithromycin [67], diclofenac [68], and cefixime [69].
