Gennadiy Itov

1 Introduction Nitrite and nitrate ions are important species in biological and artificial nitrogen cycles [1-3]. They are present in industrial [4] and environmental waters [5], food products [6], and physiological systems [7]. Their accurate quantification is crucial to monitor and understand their transformations due to their health and environmental risks [8-10]. However, nitrite and nitrate often coexist in realistic solutions, and distinguishing between them is challenging.