Liquid chromatography coupled to molecular fluorescence with postcolumn UV sensitization for thimerosal and derivative compounds monitoring in environmental samples

Indirect voltammetric determination of thiomersal in influenza vaccine using photo-degradation and graphene quantum dots modified glassy carbon electrode

Thiomersal is an organomercury derivative that degrades producing thiosalicylic acid, dithiobenzoic acid and ethylmercury. It is widely used in topical pharmaceutical preparations and as preservative in vaccines and cosmetics. In this work, an electro-analytical method for thiomersal was developed using graphene quantum dots (GQDs) as a surface modifier of a glassy carbon electrode. The method rely on using square-wave voltammetry and exploring the synergistic effect between GQDs, visible radiation and the applied potential in producing very intense Hg oxidation peak during the anodic scan. A linear voltammetric response was obtained for the analyte in the concentration range from 3.0 μmol L^-1 (1.2 μg mL^-1) to 32 μmol L^-1 (12 μg mL^-1), with a detection limit of 0.9 μmol L^-1 (0.34 μg mL^-1). The proposed method was successfully applied for thiomersal determination in influenza vaccine.