The non-additivity of the reduction currents of acrylamide (AA) and oxygen and of AA and hydrogen peroxide is reported. These results were obtained using hydrodynamic voltammetry at a rotating mercury covered gold electrode in solutions of 0.10 M tetramethylammonium hydroxide and 0.10 M LiCI. In air and oxygen saturated solutions AA limiting currents were 6-40% lower than in oxygen free solutions. The decreases in the apparent AA currents were greater when the AA/O-2 concentration ratio was smaller. An explanation for the non-additivity is proposed. These results have implications regarding the determination of AA using electrochemical detection when the analyte concentrations are small and rigorous exclusion of oxygen is difficult, e.g., HPLC-EC. (C) 2013 Elsevier B.V. All rights reserved.