Second-order electrochemical data generation to quantify carvacrol in oregano essential oils

•A novel electroanalytical method was developed to determine CAR in OEO samples.•Second-order cyclic voltammetry data were generated varying the scan rate.•The CAR determination was performed in presence of thymol as a potential interferent.•MCR-ALS was successfully used to obtain the second order advantage. A novel analytical method using voltammetric second-order modeling based on multivariate curve resolution-alternating least-square (MCR-ALS) is presented for the first time for the quantitation of carvacrol (CAR) in oregano essential oils (OEO). The second-order cyclic voltammetry data were generated on the basis that CAR shows a diffusional system. Thus, the scan rate (v) was used as a second instrumental mode and cyclic voltammograms at different v were acquired for a single sample, generating the second-order data. CAR determination was performed in presence of thymol, included as a potential interferent. Results demonstrated that MCR-ALS successfully exploited the second-order advantage and the recoveries were not statistically different than 100%. The limits of detection and quantitation were estimated using the MCR-ALS which were 6.27 × 10−5°mol°L−1°and 1.90 × 10−4°mol L−1, respectively. Finally, the developed methodology was implemented to quantify of CAR in OEO samples.