Direct recognition and quantification by voltammetry of thiol/thioamide mixes in seawater

► Thiols and thioamides distinctive peak height and potential vs deposition potential profiles. ► Thioamide copper complexes are not electrolabile. ► Individual quantification in thiol/thioamide mixes is achieved despite coalescence. ► In natural samples, first time the heterogeneity in single signals is unveiled.