Electrochemical study for the simultaneous determination of phenolic compounds and emerging pollutant using an electroanalytical sensing system based on carbon nanotubes/surfactant and multivariate approach in the optimization

A voltammetric method for the simultaneous determination of phenolic compounds hydroquinone (HQ), catechol (CT), 4-nitrophenol (p-NP), and the emerging pollutant acetaminophen (AC) using a multi-walled carbon nanotubes (MWCNT) paste electrode in the presence of surfactant has been described. The relationship of oxidation potential and pH revels a Nernstian system for all compounds and the calculated diffusion coefficients were found to be 5.45 × 10− 6, 3.35 × 10− 5, 1.17 × 10− 5, and 2.60 × 10− 6 cm2 s− 1 for HQ, CT, AC, and p-NP, respectively. The best analytical condition for the simultaneous determination of phenolic compounds has been achieved by using a multi-response optimization approach. Under the optimum condition-Britton-Robinson buffer at 0.1 mol L− 1 pH 8, CPB at 450 μmol L− 1, and differential pulse voltammetry (pulse amplitude of 117 mV, pulse time of 23.98 ms, and scan rate of 8.61 mV s− 1), limits of detection of 0.07, 0.49, 0.29, and 0.32 μmol L− 1 for HQ, CT, AC, and p-NP were obtained, respectively. The method permits the simultaneous analysis in the presence of some pesticides and other phenolic compounds. The developed method was applied in water (tap and domestic wastewater) and dermatological creams, whose accuracy has been attested through addition and recovery assays and comparing with HPLC-DAD as a reference method.