In this presentation, the applicability of nitrogen microwave-sustained inductively coupled atmospheric-pressure plasma-mass spectrometry operated in single-event mode has been evaluated for the analysis of discrete entities such as engineered metallic nanoparticles, biological cells, or microplastics. The suitability of the technique for detecting these tiny individual entities with high sensitivity, free from spectral interference, has been assessed. Special attention has been paid to the elements heavily interfered within Ar-based plasmas, such as Ca, Fe and Se, whose most abundant isotopes (40, 56 and 80 amu, respectively) traditionally overlap with Ar⁺, ArO⁺ and Ar₂⁺ interferences. The figures-of-merit for the characterization of nanoparticles and the analysis of cells, where these target elements are especially relevant, will be discussed, along with the suitability of N₂ plasmas for handling discrete entities in single-event mode.