Electrochemical Characterization and Detection of Ascorbic Acid in Garlic Using Activated Glassy Carbon Electrode: a Comprehensive Study

This study delves into the electrochemical properties of ascorbic acid (AA) in garlic bulbs, employing both a glassy carbon electrode (GCE) and an activated glassy carbon electrode (AGCE). Cyclic voltammetry (CV) and square wave voltammetry (SWV) were utilized for the thorough characterization and detection of AA in freshly harvested garlic bulbs sourced from Debark, Ethiopia. The AGCE was meticulously prepared through a 200-s activation process at a potential of 1750 mV. Demonstrating remarkable electrocatalytic behavior towards AA, the AGCE exhibited enhanced peak current and a less positive shift in peak potential compared to the GCE. It demonstrated an increase with pH up to 6.5, followed by a decrease beyond pH 6.5, leading to the selection of pH 6.5 as the optimal value. The variation in scan rate indicated an adsorption-controlled process. The established calibration curve equation was Ip (μA) =  − 9.94 – 0.15CAA, presenting a high R² value of 0.999 within the linear range of 0.01 – 0.2 mM. The method demonstrated a low limit of detection (0.004 mM) and quantification (0.012 mM). A robust degree of recovery (102.2%) validated the method’s accuracy. The concentration of AA in fresh garlic bulbs was determined to be 192.8 mg/kg, affirming the method’s suitability for the analysis of real environmental samples.