Voltammetric determination of antioxidant 4,4′-methylenebis(2,6-di-tert-butylphenol) in lubricating oils using gold disc electrode

Abstract

A novel method for voltammetric determination of 4,4′-methylenebis(2,6-di-tert-butylphenol) antioxidant was developed employing linear sweep voltammetry and gold working electrode. Different supporting electrolytes were applied during development of this methodology and 0.05 mol dm−3 H2SO4 containing ethanol with 6.6 % toluene was selected as the suitable medium to ensure a sufficient solubility of the analyte. In this work, the electrochemical behavior of the mentioned antioxidant was investigated and different voltammetric techniques were compared. The developed method based on linear sweep voltammetry was purposed for determination of the antioxidant in base oil. It was found that this matrix does not allow the direct voltammetric determination of the antioxidant, thus, the sample pretreatment, namely the extraction with ethanol, was necessary. The proposed electroanalytical method enabled the determination of antioxidants in model and real samples with satisfactory results and provides good prospects for practical analysis.