Voltammetric determination of carvacrol on Boron Doped Diamond Electrode

Highlights: • A simple, sensitive and rapid method of carvacrol determination using BDDE and Differential Pulse Voltammetry was described. • This is the first presentation of electrochemical method to determine of carvacrol on BDDE. • The calibration graph was linear from 0.29 to 15.03 mgL⁻¹ of carvacrol, LOD was 0.02 mgL⁻¹ with R = 0.9990. • The proposed method was verified by successful determination of carvacrol in commercially available oregano essential oil. -- Abstract: A simple, sensitive and rapid method of carvacrol determination using Boron Doped Diamond Electrode (BDDE) and Differential Pulse Voltammetry (DPV) was described. To the best of our knowledge, this is the first presentation of electrochemical method to determine this compound on BDDE. In presented conditions, carvacrol undergoes irreversible one-electron oxidation controlled by diffusion. The measurement conditions and composition of supporting electrolyte were developed and optimized. Optimal measurement parameters were achieved using 0.1 molL^-1 acetate buffer pH 6.0 as supporting electrolyte. The calibration graph was linear from 0.29 to 15.03 mgL⁻¹ of carvacrol, the detection limit was 0.02 mgL⁻¹ with the correlation coefficient of 0.9990. The influence of interfering metal ions, such as Cd²⁺, Cr³⁺ and Pb²⁺, was studied. The influence of thymol on the measurement results was also examined. The proposed method was verified by successful determination of carvacrol in commercially available oregano essential oil. Recovery of carvacrol added to the extracts obtained from fresh and dried parts of oregano and marjoram was successfully estimated. Effective application of the described analytical approach, not only enables the electrochemical detection of carvacrol, but also helps to reduce the operational cost.